security/tomoyo/common.c

   1 /*
   2  * security/tomoyo/common.c
   3  *
   4  * Common functions for TOMOYO.
   5  *
   6  * Copyright (C) 2005-2010  NTT DATA CORPORATION
   7  */
   8
   9 #include <linux/uaccess.h>
  10 #include <linux/slab.h>
  11 #include <linux/security.h>
  12 #include "common.h"
  13
  14 static struct tomoyo_profile tomoyo_default_profile = {
  15         .learning = &tomoyo_default_profile.preference,
  16         .permissive = &tomoyo_default_profile.preference,
  17         .enforcing = &tomoyo_default_profile.preference,
  18         .preference.enforcing_verbose = true,
  19         .preference.learning_max_entry = 2048,
  20         .preference.learning_verbose = false,
  21         .preference.permissive_verbose = true
  22 };
  23
  24 /* Profile version. Currently only 20090903 is defined. */
  25 static unsigned int tomoyo_profile_version;
  26
  27 /* Profile table. Memory is allocated as needed. */
  28 static struct tomoyo_profile *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
  29
  30 /* String table for functionality that takes 4 modes. */
  31 static const char *tomoyo_mode[4] = {
  32         "disabled", "learning", "permissive", "enforcing"
  33 };
  34
  35 /* String table for /sys/kernel/security/tomoyo/profile */
  36 static const char *tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
  37                                        + TOMOYO_MAX_MAC_CATEGORY_INDEX] = {
  38         [TOMOYO_MAC_FILE_EXECUTE]    = "file::execute",
  39         [TOMOYO_MAC_FILE_OPEN]       = "file::open",
  40         [TOMOYO_MAC_FILE_CREATE]     = "file::create",
  41         [TOMOYO_MAC_FILE_UNLINK]     = "file::unlink",
  42         [TOMOYO_MAC_FILE_GETATTR]    = "file::getattr",
  43         [TOMOYO_MAC_FILE_MKDIR]      = "file::mkdir",
  44         [TOMOYO_MAC_FILE_RMDIR]      = "file::rmdir",
  45         [TOMOYO_MAC_FILE_MKFIFO]     = "file::mkfifo",
  46         [TOMOYO_MAC_FILE_MKSOCK]     = "file::mksock",
  47         [TOMOYO_MAC_FILE_TRUNCATE]   = "file::truncate",
  48         [TOMOYO_MAC_FILE_SYMLINK]    = "file::symlink",
  49         [TOMOYO_MAC_FILE_MKBLOCK]    = "file::mkblock",
  50         [TOMOYO_MAC_FILE_MKCHAR]     = "file::mkchar",
  51         [TOMOYO_MAC_FILE_LINK]       = "file::link",
  52         [TOMOYO_MAC_FILE_RENAME]     = "file::rename",
  53         [TOMOYO_MAC_FILE_CHMOD]      = "file::chmod",
  54         [TOMOYO_MAC_FILE_CHOWN]      = "file::chown",
  55         [TOMOYO_MAC_FILE_CHGRP]      = "file::chgrp",
  56         [TOMOYO_MAC_FILE_IOCTL]      = "file::ioctl",
  57         [TOMOYO_MAC_FILE_CHROOT]     = "file::chroot",
  58         [TOMOYO_MAC_FILE_MOUNT]      = "file::mount",
  59         [TOMOYO_MAC_FILE_UMOUNT]     = "file::umount",
  60         [TOMOYO_MAC_FILE_PIVOT_ROOT] = "file::pivot_root",
  61         [TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_FILE] = "file",
  62 };
  63
  64 /* Permit policy management by non-root user? */
  65 static bool tomoyo_manage_by_non_root;
  66
  67 /* Utility functions. */
  68
  69 /**
  70  * tomoyo_yesno - Return "yes" or "no".
  71  *
  72  * @value: Bool value.
  73  */
  74 static const char *tomoyo_yesno(const unsigned int value)
  75 {
  76         return value ? "yes" : "no";
  77 }
  78
  79 static void tomoyo_addprintf(char *buffer, int len, const char *fmt, ...)
  80 {
  81         va_list args;
  82         const int pos = strlen(buffer);
  83         va_start(args, fmt);
  84         vsnprintf(buffer + pos, len - pos - 1, fmt, args);
  85         va_end(args);
  86 }
  87
  88 /**
  89  * tomoyo_flush - Flush queued string to userspace's buffer.
  90  *
  91  * @head:   Pointer to "struct tomoyo_io_buffer".
  92  *
  93  * Returns true if all data was flushed, false otherwise.
  94  */
  95 static bool tomoyo_flush(struct tomoyo_io_buffer *head)
  96 {
  97         while (head->r.w_pos) {
  98                 const char *w = head->r.w[0];
  99                 int len = strlen(w);
 100                 if (len) {
 101                         if (len > head->read_user_buf_avail)
 102                                 len = head->read_user_buf_avail;
 103                         if (!len)
 104                                 return false;
 105                         if (copy_to_user(head->read_user_buf, w, len))
 106                                 return false;
 107                         head->read_user_buf_avail -= len;
 108                         head->read_user_buf += len;
 109                         w += len;
 110                 }
 111                 head->r.w[0] = w;
 112                 if (*w)
 113                         return false;
 114                 /* Add '\0' for query. */
 115                 if (head->poll) {
 116                         if (!head->read_user_buf_avail ||
 117                             copy_to_user(head->read_user_buf, "", 1))
 118                                 return false;
 119                         head->read_user_buf_avail--;
 120                         head->read_user_buf++;
 121                 }
 122                 head->r.w_pos--;
 123                 for (len = 0; len < head->r.w_pos; len++)
 124                         head->r.w[len] = head->r.w[len + 1];
 125         }
 126         head->r.avail = 0;
 127         return true;
 128 }
 129
 130 /**
 131  * tomoyo_set_string - Queue string to "struct tomoyo_io_buffer" structure.
 132  *
 133  * @head:   Pointer to "struct tomoyo_io_buffer".
 134  * @string: String to print.
 135  *
 136  * Note that @string has to be kept valid until @head is kfree()d.
 137  * This means that char[] allocated on stack memory cannot be passed to
 138  * this function. Use tomoyo_io_printf() for char[] allocated on stack memory.
 139  */
 140 static void tomoyo_set_string(struct tomoyo_io_buffer *head, const char *string)
 141 {
 142         if (head->r.w_pos < TOMOYO_MAX_IO_READ_QUEUE) {
 143                 head->r.w[head->r.w_pos++] = string;
 144                 tomoyo_flush(head);
 145         } else
 146                 WARN_ON(1);
 147 }
 148
 149 /**
 150  * tomoyo_io_printf - printf() to "struct tomoyo_io_buffer" structure.
 151  *
 152  * @head: Pointer to "struct tomoyo_io_buffer".
 153  * @fmt:  The printf()'s format string, followed by parameters.
 154  */
 155 void tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 156 {
 157         va_list args;
 158         int len;
 159         int pos = head->r.avail;
 160         int size = head->readbuf_size - pos;
 161         if (size <= 0)
 162                 return;
 163         va_start(args, fmt);
 164         len = vsnprintf(head->read_buf + pos, size, fmt, args) + 1;
 165         va_end(args);
 166         if (pos + len >= head->readbuf_size) {
 167                 WARN_ON(1);
 168                 return;
 169         }
 170         head->r.avail += len;
 171         tomoyo_set_string(head, head->read_buf + pos);
 172 }
 173
 174 static void tomoyo_set_space(struct tomoyo_io_buffer *head)
 175 {
 176         tomoyo_set_string(head, " ");
 177 }
 178
 179 static bool tomoyo_set_lf(struct tomoyo_io_buffer *head)
 180 {
 181         tomoyo_set_string(head, "\n");
 182         return !head->r.w_pos;
 183 }
 184
 185 /**
 186  * tomoyo_print_name_union - Print a tomoyo_name_union.
 187  *
 188  * @head: Pointer to "struct tomoyo_io_buffer".
 189  * @ptr:  Pointer to "struct tomoyo_name_union".
 190  */
 191 static void tomoyo_print_name_union(struct tomoyo_io_buffer *head,
 192                                     const struct tomoyo_name_union *ptr)
 193 {
 194         tomoyo_set_space(head);
 195         if (ptr->group) {
 196                 tomoyo_set_string(head, "@");
 197                 tomoyo_set_string(head, ptr->group->group_name->name);
 198         } else {
 199                 tomoyo_set_string(head, ptr->filename->name);
 200         }
 201 }
 202
 203 /**
 204  * tomoyo_print_number_union - Print a tomoyo_number_union.
 205  *
 206  * @head:       Pointer to "struct tomoyo_io_buffer".
 207  * @ptr:        Pointer to "struct tomoyo_number_union".
 208  */
 209 static void tomoyo_print_number_union(struct tomoyo_io_buffer *head,
 210                                       const struct tomoyo_number_union *ptr)
 211 {
 212         tomoyo_set_space(head);
 213         if (ptr->group) {
 214                 tomoyo_set_string(head, "@");
 215                 tomoyo_set_string(head, ptr->group->group_name->name);
 216         } else {
 217                 int i;
 218                 unsigned long min = ptr->values[0];
 219                 const unsigned long max = ptr->values[1];
 220                 u8 min_type = ptr->value_type[0];
 221                 const u8 max_type = ptr->value_type[1];
 222                 char buffer[128];
 223                 buffer[0] = '\0';
 224                 for (i = 0; i < 2; i++) {
 225                         switch (min_type) {
 226                         case TOMOYO_VALUE_TYPE_HEXADECIMAL:
 227                                 tomoyo_addprintf(buffer, sizeof(buffer),
 228                                                  "0x%lX", min);
 229                                 break;
 230                         case TOMOYO_VALUE_TYPE_OCTAL:
 231                                 tomoyo_addprintf(buffer, sizeof(buffer),
 232                                                  "0%lo", min);
 233                                 break;
 234                         default:
 235                                 tomoyo_addprintf(buffer, sizeof(buffer),
 236                                                  "%lu", min);
 237                                 break;
 238                         }
 239                         if (min == max && min_type == max_type)
 240                                 break;
 241                         tomoyo_addprintf(buffer, sizeof(buffer), "-");
 242                         min_type = max_type;
 243                         min = max;
 244                 }
 245                 tomoyo_io_printf(head, "%s", buffer);
 246         }
 247 }
 248
 249 /**
 250  * tomoyo_assign_profile - Create a new profile.
 251  *
 252  * @profile: Profile number to create.
 253  *
 254  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 255  */
 256 static struct tomoyo_profile *tomoyo_assign_profile(const unsigned int profile)
 257 {
 258         struct tomoyo_profile *ptr;
 259         struct tomoyo_profile *entry;
 260         if (profile >= TOMOYO_MAX_PROFILES)
 261                 return NULL;
 262         ptr = tomoyo_profile_ptr[profile];
 263         if (ptr)
 264                 return ptr;
 265         entry = kzalloc(sizeof(*entry), GFP_NOFS);
 266         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 267                 goto out;
 268         ptr = tomoyo_profile_ptr[profile];
 269         if (!ptr && tomoyo_memory_ok(entry)) {
 270                 ptr = entry;
 271                 ptr->learning = &tomoyo_default_profile.preference;
 272                 ptr->permissive = &tomoyo_default_profile.preference;
 273                 ptr->enforcing = &tomoyo_default_profile.preference;
 274                 ptr->default_config = TOMOYO_CONFIG_DISABLED;
 275                 memset(ptr->config, TOMOYO_CONFIG_USE_DEFAULT,
 276                        sizeof(ptr->config));
 277                 mb(); /* Avoid out-of-order execution. */
 278                 tomoyo_profile_ptr[profile] = ptr;
 279                 entry = NULL;
 280         }
 281         mutex_unlock(&tomoyo_policy_lock);
 282  out:
 283         kfree(entry);
 284         return ptr;
 285 }
 286
 287 /**
 288  * tomoyo_profile - Find a profile.
 289  *
 290  * @profile: Profile number to find.
 291  *
 292  * Returns pointer to "struct tomoyo_profile".
 293  */
 294 struct tomoyo_profile *tomoyo_profile(const u8 profile)
 295 {
 296         struct tomoyo_profile *ptr = tomoyo_profile_ptr[profile];
 297         if (!tomoyo_policy_loaded)
 298                 return &tomoyo_default_profile;
 299         BUG_ON(!ptr);
 300         return ptr;
 301 }
 302
 303 static s8 tomoyo_find_yesno(const char *string, const char *find)
 304 {
 305         const char *cp = strstr(string, find);
 306         if (cp) {
 307                 cp += strlen(find);
 308                 if (!strncmp(cp, "=yes", 4))
 309                         return 1;
 310                 else if (!strncmp(cp, "=no", 3))
 311                         return 0;
 312         }
 313         return -1;
 314 }
 315
 316 static void tomoyo_set_bool(bool *b, const char *string, const char *find)
 317 {
 318         switch (tomoyo_find_yesno(string, find)) {
 319         case 1:
 320                 *b = true;
 321                 break;
 322         case 0:
 323                 *b = false;
 324                 break;
 325         }
 326 }
 327
 328 static void tomoyo_set_uint(unsigned int *i, const char *string,
 329                             const char *find)
 330 {
 331         const char *cp = strstr(string, find);
 332         if (cp)
 333                 sscanf(cp + strlen(find), "=%u", i);
 334 }
 335
 336 static void tomoyo_set_pref(const char *name, const char *value,
 337                             const bool use_default,
 338                             struct tomoyo_profile *profile)
 339 {
 340         struct tomoyo_preference **pref;
 341         bool *verbose;
 342         if (!strcmp(name, "enforcing")) {
 343                 if (use_default) {
 344                         pref = &profile->enforcing;
 345                         goto set_default;
 346                 }
 347                 profile->enforcing = &profile->preference;
 348                 verbose = &profile->preference.enforcing_verbose;
 349                 goto set_verbose;
 350         }
 351         if (!strcmp(name, "permissive")) {
 352                 if (use_default) {
 353                         pref = &profile->permissive;
 354                         goto set_default;
 355                 }
 356                 profile->permissive = &profile->preference;
 357                 verbose = &profile->preference.permissive_verbose;
 358                 goto set_verbose;
 359         }
 360         if (!strcmp(name, "learning")) {
 361                 if (use_default) {
 362                         pref = &profile->learning;
 363                         goto set_default;
 364                 }
 365                 profile->learning = &profile->preference;
 366                 tomoyo_set_uint(&profile->preference.learning_max_entry, value,
 367                              "max_entry");
 368                 verbose = &profile->preference.learning_verbose;
 369                 goto set_verbose;
 370         }
 371         return;
 372  set_default:
 373         *pref = &tomoyo_default_profile.preference;
 374         return;
 375  set_verbose:
 376         tomoyo_set_bool(verbose, value, "verbose");
 377 }
 378
 379 static int tomoyo_set_mode(char *name, const char *value,
 380                            const bool use_default,
 381                            struct tomoyo_profile *profile)
 382 {
 383         u8 i;
 384         u8 config;
 385         if (!strcmp(name, "CONFIG")) {
 386                 i = TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX;
 387                 config = profile->default_config;
 388         } else if (tomoyo_str_starts(&name, "CONFIG::")) {
 389                 config = 0;
 390                 for (i = 0; i < TOMOYO_MAX_MAC_INDEX
 391                              + TOMOYO_MAX_MAC_CATEGORY_INDEX; i++) {
 392                         if (strcmp(name, tomoyo_mac_keywords[i]))
 393                                 continue;
 394                         config = profile->config[i];
 395                         break;
 396                 }
 397                 if (i == TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
 398                         return -EINVAL;
 399         } else {
 400                 return -EINVAL;
 401         }
 402         if (use_default) {
 403                 config = TOMOYO_CONFIG_USE_DEFAULT;
 404         } else {
 405                 u8 mode;
 406                 for (mode = 0; mode < 4; mode++)
 407                         if (strstr(value, tomoyo_mode[mode]))
 408                                 /*
 409                                  * Update lower 3 bits in order to distinguish
 410                                  * 'config' from 'TOMOYO_CONFIG_USE_DEAFULT'.
 411                                  */
 412                                 config = (config & ~7) | mode;
 413         }
 414         if (i < TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
 415                 profile->config[i] = config;
 416         else if (config != TOMOYO_CONFIG_USE_DEFAULT)
 417                 profile->default_config = config;
 418         return 0;
 419 }
 420
 421 /**
 422  * tomoyo_write_profile - Write profile table.
 423  *
 424  * @head: Pointer to "struct tomoyo_io_buffer".
 425  *
 426  * Returns 0 on success, negative value otherwise.
 427  */
 428 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 429 {
 430         char *data = head->write_buf;
 431         unsigned int i;
 432         bool use_default = false;
 433         char *cp;
 434         struct tomoyo_profile *profile;
 435         if (sscanf(data, "PROFILE_VERSION=%u", &tomoyo_profile_version) == 1)
 436                 return 0;
 437         i = simple_strtoul(data, &cp, 10);
 438         if (data == cp) {
 439                 profile = &tomoyo_default_profile;
 440         } else {
 441                 if (*cp != '-')
 442                         return -EINVAL;
 443                 data = cp + 1;
 444                 profile = tomoyo_assign_profile(i);
 445                 if (!profile)
 446                         return -EINVAL;
 447         }
 448         cp = strchr(data, '=');
 449         if (!cp)
 450                 return -EINVAL;
 451         *cp++ = '\0';
 452         if (profile != &tomoyo_default_profile)
 453                 use_default = strstr(cp, "use_default") != NULL;
 454         if (tomoyo_str_starts(&data, "PREFERENCE::")) {
 455                 tomoyo_set_pref(data, cp, use_default, profile);
 456                 return 0;
 457         }
 458         if (profile == &tomoyo_default_profile)
 459                 return -EINVAL;
 460         if (!strcmp(data, "COMMENT")) {
 461                 static DEFINE_SPINLOCK(lock);
 462                 const struct tomoyo_path_info *new_comment
 463                         = tomoyo_get_name(cp);
 464                 const struct tomoyo_path_info *old_comment;
 465                 if (!new_comment)
 466                         return -ENOMEM;
 467                 spin_lock(&lock);
 468                 old_comment = profile->comment;
 469                 profile->comment = new_comment;
 470                 spin_unlock(&lock);
 471                 tomoyo_put_name(old_comment);
 472                 return 0;
 473         }
 474         return tomoyo_set_mode(data, cp, use_default, profile);
 475 }
 476
 477 static void tomoyo_print_preference(struct tomoyo_io_buffer *head,
 478                                     const int idx)
 479 {
 480         struct tomoyo_preference *pref = &tomoyo_default_profile.preference;
 481         const struct tomoyo_profile *profile = idx >= 0 ?
 482                 tomoyo_profile_ptr[idx] : NULL;
 483         char buffer[16] = "";
 484         if (profile) {
 485                 buffer[sizeof(buffer) - 1] = '\0';
 486                 snprintf(buffer, sizeof(buffer) - 1, "%u-", idx);
 487         }
 488         if (profile) {
 489                 pref = profile->learning;
 490                 if (pref == &tomoyo_default_profile.preference)
 491                         goto skip1;
 492         }
 493         tomoyo_io_printf(head, "%sPREFERENCE::%s={ "
 494                          "verbose=%s max_entry=%u }\n",
 495                          buffer, "learning",
 496                          tomoyo_yesno(pref->learning_verbose),
 497                          pref->learning_max_entry);
 498  skip1:
 499         if (profile) {
 500                 pref = profile->permissive;
 501                 if (pref == &tomoyo_default_profile.preference)
 502                         goto skip2;
 503         }
 504         tomoyo_io_printf(head, "%sPREFERENCE::%s={ verbose=%s }\n",
 505                          buffer, "permissive",
 506                          tomoyo_yesno(pref->permissive_verbose));
 507  skip2:
 508         if (profile) {
 509                 pref = profile->enforcing;
 510                 if (pref == &tomoyo_default_profile.preference)
 511                         return;
 512         }
 513         tomoyo_io_printf(head, "%sPREFERENCE::%s={ verbose=%s }\n",
 514                          buffer, "enforcing",
 515                          tomoyo_yesno(pref->enforcing_verbose));
 516 }
 517
 518 static void tomoyo_print_config(struct tomoyo_io_buffer *head, const u8 config)
 519 {
 520         tomoyo_io_printf(head, "={ mode=%s }\n", tomoyo_mode[config & 3]);
 521 }
 522
 523 /**
 524  * tomoyo_read_profile - Read profile table.
 525  *
 526  * @head: Pointer to "struct tomoyo_io_buffer".
 527  */
 528 static void tomoyo_read_profile(struct tomoyo_io_buffer *head)
 529 {
 530         u8 index;
 531         const struct tomoyo_profile *profile;
 532  next:
 533         index = head->r.index;
 534         profile = tomoyo_profile_ptr[index];
 535         switch (head->r.step) {
 536         case 0:
 537                 tomoyo_io_printf(head, "PROFILE_VERSION=%s\n", "20090903");
 538                 tomoyo_print_preference(head, -1);
 539                 head->r.step++;
 540                 break;
 541         case 1:
 542                 for ( ; head->r.index < TOMOYO_MAX_PROFILES;
 543                       head->r.index++)
 544                         if (tomoyo_profile_ptr[head->r.index])
 545                                 break;
 546                 if (head->r.index == TOMOYO_MAX_PROFILES)
 547                         return;
 548                 head->r.step++;
 549                 break;
 550         case 2:
 551                 {
 552                         const struct tomoyo_path_info *comment =
 553                                 profile->comment;
 554                         tomoyo_io_printf(head, "%u-COMMENT=", index);
 555                         tomoyo_set_string(head, comment ? comment->name : "");
 556                         tomoyo_set_lf(head);
 557                         head->r.step++;
 558                 }
 559                 break;
 560         case 3:
 561                 {
 562                         tomoyo_io_printf(head, "%u-%s", index, "CONFIG");
 563                         tomoyo_print_config(head, profile->default_config);
 564                         head->r.bit = 0;
 565                         head->r.step++;
 566                 }
 567                 break;
 568         case 4:
 569                 for ( ; head->r.bit < TOMOYO_MAX_MAC_INDEX
 570                               + TOMOYO_MAX_MAC_CATEGORY_INDEX; head->r.bit++) {
 571                         const u8 i = head->r.bit;
 572                         const u8 config = profile->config[i];
 573                         if (config == TOMOYO_CONFIG_USE_DEFAULT)
 574                                 continue;
 575                         tomoyo_io_printf(head, "%u-%s%s", index, "CONFIG::",
 576                                          tomoyo_mac_keywords[i]);
 577                         tomoyo_print_config(head, config);
 578                         head->r.bit++;
 579                         break;
 580                 }
 581                 if (head->r.bit == TOMOYO_MAX_MAC_INDEX
 582                     + TOMOYO_MAX_MAC_CATEGORY_INDEX) {
 583                         tomoyo_print_preference(head, index);
 584                         head->r.index++;
 585                         head->r.step = 1;
 586                 }
 587                 break;
 588         }
 589         if (tomoyo_flush(head))
 590                 goto next;
 591 }
 592
 593 static bool tomoyo_same_manager(const struct tomoyo_acl_head *a,
 594                                 const struct tomoyo_acl_head *b)
 595 {
 596         return container_of(a, struct tomoyo_manager, head)->manager ==
 597                 container_of(b, struct tomoyo_manager, head)->manager;
 598 }
 599
 600 /**
 601  * tomoyo_update_manager_entry - Add a manager entry.
 602  *
 603  * @manager:   The path to manager or the domainnamme.
 604  * @is_delete: True if it is a delete request.
 605  *
 606  * Returns 0 on success, negative value otherwise.
 607  *
 608  * Caller holds tomoyo_read_lock().
 609  */
 610 static int tomoyo_update_manager_entry(const char *manager,
 611                                        const bool is_delete)
 612 {
 613         struct tomoyo_manager e = { };
 614         int error;
 615
 616         if (tomoyo_domain_def(manager)) {
 617                 if (!tomoyo_correct_domain(manager))
 618                         return -EINVAL;
 619                 e.is_domain = true;
 620         } else {
 621                 if (!tomoyo_correct_path(manager))
 622                         return -EINVAL;
 623         }
 624         e.manager = tomoyo_get_name(manager);
 625         if (!e.manager)
 626                 return -ENOMEM;
 627         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
 628                                      &tomoyo_policy_list[TOMOYO_ID_MANAGER],
 629                                      tomoyo_same_manager);
 630         tomoyo_put_name(e.manager);
 631         return error;
 632 }
 633
 634 /**
 635  * tomoyo_write_manager - Write manager policy.
 636  *
 637  * @head: Pointer to "struct tomoyo_io_buffer".
 638  *
 639  * Returns 0 on success, negative value otherwise.
 640  *
 641  * Caller holds tomoyo_read_lock().
 642  */
 643 static int tomoyo_write_manager(struct tomoyo_io_buffer *head)
 644 {
 645         char *data = head->write_buf;
 646         bool is_delete = tomoyo_str_starts(&data, "delete ");
 647
 648         if (!strcmp(data, "manage_by_non_root")) {
 649                 tomoyo_manage_by_non_root = !is_delete;
 650                 return 0;
 651         }
 652         return tomoyo_update_manager_entry(data, is_delete);
 653 }
 654
 655 /**
 656  * tomoyo_read_manager - Read manager policy.
 657  *
 658  * @head: Pointer to "struct tomoyo_io_buffer".
 659  *
 660  * Caller holds tomoyo_read_lock().
 661  */
 662 static void tomoyo_read_manager(struct tomoyo_io_buffer *head)
 663 {
 664         if (head->r.eof)
 665                 return;
 666         list_for_each_cookie(head->r.acl,
 667                              &tomoyo_policy_list[TOMOYO_ID_MANAGER]) {
 668                 struct tomoyo_manager *ptr =
 669                         list_entry(head->r.acl, typeof(*ptr), head.list);
 670                 if (ptr->head.is_deleted)
 671                         continue;
 672                 if (!tomoyo_flush(head))
 673                         return;
 674                 tomoyo_set_string(head, ptr->manager->name);
 675                 tomoyo_set_lf(head);
 676         }
 677         head->r.eof = true;
 678 }
 679
 680 /**
 681  * tomoyo_manager - Check whether the current process is a policy manager.
 682  *
 683  * Returns true if the current process is permitted to modify policy
 684  * via /sys/kernel/security/tomoyo/ interface.
 685  *
 686  * Caller holds tomoyo_read_lock().
 687  */
 688 static bool tomoyo_manager(void)
 689 {
 690         struct tomoyo_manager *ptr;
 691         const char *exe;
 692         const struct task_struct *task = current;
 693         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
 694         bool found = false;
 695
 696         if (!tomoyo_policy_loaded)
 697                 return true;
 698         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
 699                 return false;
 700         list_for_each_entry_rcu(ptr, &tomoyo_policy_list[TOMOYO_ID_MANAGER],
 701                                 head.list) {
 702                 if (!ptr->head.is_deleted && ptr->is_domain
 703                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
 704                         found = true;
 705                         break;
 706                 }
 707         }
 708         if (found)
 709                 return true;
 710         exe = tomoyo_get_exe();
 711         if (!exe)
 712                 return false;
 713         list_for_each_entry_rcu(ptr, &tomoyo_policy_list[TOMOYO_ID_MANAGER],
 714                                 head.list) {
 715                 if (!ptr->head.is_deleted && !ptr->is_domain
 716                     && !strcmp(exe, ptr->manager->name)) {
 717                         found = true;
 718                         break;
 719                 }
 720         }
 721         if (!found) { /* Reduce error messages. */
 722                 static pid_t last_pid;
 723                 const pid_t pid = current->pid;
 724                 if (last_pid != pid) {
 725                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
 726                                "update policies.\n", domainname->name, exe);
 727                         last_pid = pid;
 728                 }
 729         }
 730         kfree(exe);
 731         return found;
 732 }
 733
 734 /**
 735  * tomoyo_select_one - Parse select command.
 736  *
 737  * @head: Pointer to "struct tomoyo_io_buffer".
 738  * @data: String to parse.
 739  *
 740  * Returns true on success, false otherwise.
 741  *
 742  * Caller holds tomoyo_read_lock().
 743  */
 744 static bool tomoyo_select_one(struct tomoyo_io_buffer *head, const char *data)
 745 {
 746         unsigned int pid;
 747         struct tomoyo_domain_info *domain = NULL;
 748         bool global_pid = false;
 749
 750         if (!strcmp(data, "allow_execute")) {
 751                 head->r.print_execute_only = true;
 752                 return true;
 753         }
 754         if (sscanf(data, "pid=%u", &pid) == 1 ||
 755             (global_pid = true, sscanf(data, "global-pid=%u", &pid) == 1)) {
 756                 struct task_struct *p;
 757                 rcu_read_lock();
 758                 read_lock(&tasklist_lock);
 759                 if (global_pid)
 760                         p = find_task_by_pid_ns(pid, &init_pid_ns);
 761                 else
 762                         p = find_task_by_vpid(pid);
 763                 if (p)
 764                         domain = tomoyo_real_domain(p);
 765                 read_unlock(&tasklist_lock);
 766                 rcu_read_unlock();
 767         } else if (!strncmp(data, "domain=", 7)) {
 768                 if (tomoyo_domain_def(data + 7))
 769                         domain = tomoyo_find_domain(data + 7);
 770         } else
 771                 return false;
 772         head->w.domain = domain;
 773         /* Accessing read_buf is safe because head->io_sem is held. */
 774         if (!head->read_buf)
 775                 return true; /* Do nothing if open(O_WRONLY). */
 776         memset(&head->r, 0, sizeof(head->r));
 777         head->r.print_this_domain_only = true;
 778         if (domain)
 779                 head->r.domain = &domain->list;
 780         else
 781                 head->r.eof = 1;
 782         tomoyo_io_printf(head, "# select %s\n", data);
 783         if (domain && domain->is_deleted)
 784                 tomoyo_io_printf(head, "# This is a deleted domain.\n");
 785         return true;
 786 }
 787
 788 /**
 789  * tomoyo_delete_domain - Delete a domain.
 790  *
 791  * @domainname: The name of domain.
 792  *
 793  * Returns 0.
 794  *
 795  * Caller holds tomoyo_read_lock().
 796  */
 797 static int tomoyo_delete_domain(char *domainname)
 798 {
 799         struct tomoyo_domain_info *domain;
 800         struct tomoyo_path_info name;
 801
 802         name.name = domainname;
 803         tomoyo_fill_path_info(&name);
 804         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 805                 return 0;
 806         /* Is there an active domain? */
 807         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 808                 /* Never delete tomoyo_kernel_domain */
 809                 if (domain == &tomoyo_kernel_domain)
 810                         continue;
 811                 if (domain->is_deleted ||
 812                     tomoyo_pathcmp(domain->domainname, &name))
 813                         continue;
 814                 domain->is_deleted = true;
 815                 break;
 816         }
 817         mutex_unlock(&tomoyo_policy_lock);
 818         return 0;
 819 }
 820
 821 /**
 822  * tomoyo_write_domain2 - Write domain policy.
 823  *
 824  * @head: Pointer to "struct tomoyo_io_buffer".
 825  *
 826  * Returns 0 on success, negative value otherwise.
 827  *
 828  * Caller holds tomoyo_read_lock().
 829  */
 830 static int tomoyo_write_domain2(char *data, struct tomoyo_domain_info *domain,
 831                                 const bool is_delete)
 832 {
 833         if (tomoyo_str_starts(&data, "allow_mount "))
 834                 return tomoyo_write_mount(data, domain, is_delete);
 835         return tomoyo_write_file(data, domain, is_delete);
 836 }
 837
 838 /**
 839  * tomoyo_write_domain - Write domain policy.
 840  *
 841  * @head: Pointer to "struct tomoyo_io_buffer".
 842  *
 843  * Returns 0 on success, negative value otherwise.
 844  *
 845  * Caller holds tomoyo_read_lock().
 846  */
 847 static int tomoyo_write_domain(struct tomoyo_io_buffer *head)
 848 {
 849         char *data = head->write_buf;
 850         struct tomoyo_domain_info *domain = head->w.domain;
 851         bool is_delete = false;
 852         bool is_select = false;
 853         unsigned int profile;
 854
 855         if (tomoyo_str_starts(&data, "delete "))
 856                 is_delete = true;
 857         else if (tomoyo_str_starts(&data, "select "))
 858                 is_select = true;
 859         if (is_select && tomoyo_select_one(head, data))
 860                 return 0;
 861         /* Don't allow updating policies by non manager programs. */
 862         if (!tomoyo_manager())
 863                 return -EPERM;
 864         if (tomoyo_domain_def(data)) {
 865                 domain = NULL;
 866                 if (is_delete)
 867                         tomoyo_delete_domain(data);
 868                 else if (is_select)
 869                         domain = tomoyo_find_domain(data);
 870                 else
 871                         domain = tomoyo_assign_domain(data, 0);
 872                 head->w.domain = domain;
 873                 return 0;
 874         }
 875         if (!domain)
 876                 return -EINVAL;
 877
 878         if (sscanf(data, "use_profile %u", &profile) == 1
 879             && profile < TOMOYO_MAX_PROFILES) {
 880                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
 881                         domain->profile = (u8) profile;
 882                 return 0;
 883         }
 884         if (!strcmp(data, "quota_exceeded")) {
 885                 domain->quota_warned = !is_delete;
 886                 return 0;
 887         }
 888         if (!strcmp(data, "transition_failed")) {
 889                 domain->transition_failed = !is_delete;
 890                 return 0;
 891         }
 892         return tomoyo_write_domain2(data, domain, is_delete);
 893 }
 894
 895 /**
 896  * tomoyo_fns - Find next set bit.
 897  *
 898  * @perm: 8 bits value.
 899  * @bit:  First bit to find.
 900  *
 901  * Returns next on-bit on success, 8 otherwise.
 902  */
 903 static u8 tomoyo_fns(const u8 perm, u8 bit)
 904 {
 905         for ( ; bit < 8; bit++)
 906                 if (perm & (1 << bit))
 907                         break;
 908         return bit;
 909 }
 910
 911 /**
 912  * tomoyo_print_entry - Print an ACL entry.
 913  *
 914  * @head: Pointer to "struct tomoyo_io_buffer".
 915  * @acl:  Pointer to an ACL entry.
 916  *
 917  * Returns true on success, false otherwise.
 918  */
 919 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
 920                                struct tomoyo_acl_info *acl)
 921 {
 922         const u8 acl_type = acl->type;
 923         u8 bit;
 924
 925         if (acl->is_deleted)
 926                 return true;
 927  next:
 928         bit = head->r.bit;
 929         if (!tomoyo_flush(head))
 930                 return false;
 931         else if (acl_type == TOMOYO_TYPE_PATH_ACL) {
 932                 struct tomoyo_path_acl *ptr =
 933                         container_of(acl, typeof(*ptr), head);
 934                 const u16 perm = ptr->perm;
 935                 for ( ; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
 936                         if (!(perm & (1 << bit)))
 937                                 continue;
 938                         if (head->r.print_execute_only &&
 939                             bit != TOMOYO_TYPE_EXECUTE)
 940                                 continue;
 941                         break;
 942                 }
 943                 if (bit >= TOMOYO_MAX_PATH_OPERATION)
 944                         goto done;
 945                 tomoyo_io_printf(head, "allow_%s", tomoyo_path_keyword[bit]);
 946                 tomoyo_print_name_union(head, &ptr->name);
 947         } else if (head->r.print_execute_only) {
 948                 return true;
 949         } else if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
 950                 struct tomoyo_path2_acl *ptr =
 951                         container_of(acl, typeof(*ptr), head);
 952                 bit = tomoyo_fns(ptr->perm, bit);
 953                 if (bit >= TOMOYO_MAX_PATH2_OPERATION)
 954                         goto done;
 955                 tomoyo_io_printf(head, "allow_%s", tomoyo_path2_keyword[bit]);
 956                 tomoyo_print_name_union(head, &ptr->name1);
 957                 tomoyo_print_name_union(head, &ptr->name2);
 958         } else if (acl_type == TOMOYO_TYPE_PATH_NUMBER_ACL) {
 959                 struct tomoyo_path_number_acl *ptr =
 960                         container_of(acl, typeof(*ptr), head);
 961                 bit = tomoyo_fns(ptr->perm, bit);
 962                 if (bit >= TOMOYO_MAX_PATH_NUMBER_OPERATION)
 963                         goto done;
 964                 tomoyo_io_printf(head, "allow_%s",
 965                                  tomoyo_path_number_keyword[bit]);
 966                 tomoyo_print_name_union(head, &ptr->name);
 967                 tomoyo_print_number_union(head, &ptr->number);
 968         } else if (acl_type == TOMOYO_TYPE_MKDEV_ACL) {
 969                 struct tomoyo_mkdev_acl *ptr =
 970                         container_of(acl, typeof(*ptr), head);
 971                 bit = tomoyo_fns(ptr->perm, bit);
 972                 if (bit >= TOMOYO_MAX_MKDEV_OPERATION)
 973                         goto done;
 974                 tomoyo_io_printf(head, "allow_%s", tomoyo_mkdev_keyword[bit]);
 975                 tomoyo_print_name_union(head, &ptr->name);
 976                 tomoyo_print_number_union(head, &ptr->mode);
 977                 tomoyo_print_number_union(head, &ptr->major);
 978                 tomoyo_print_number_union(head, &ptr->minor);
 979         } else if (acl_type == TOMOYO_TYPE_MOUNT_ACL) {
 980                 struct tomoyo_mount_acl *ptr =
 981                         container_of(acl, typeof(*ptr), head);
 982                 tomoyo_io_printf(head, "allow_mount");
 983                 tomoyo_print_name_union(head, &ptr->dev_name);
 984                 tomoyo_print_name_union(head, &ptr->dir_name);
 985                 tomoyo_print_name_union(head, &ptr->fs_type);
 986                 tomoyo_print_number_union(head, &ptr->flags);
 987         }
 988         head->r.bit = bit + 1;
 989         tomoyo_io_printf(head, "\n");
 990         if (acl_type != TOMOYO_TYPE_MOUNT_ACL)
 991                 goto next;
 992  done:
 993         head->r.bit = 0;
 994         return true;
 995 }
 996
 997 /**
 998  * tomoyo_read_domain2 - Read domain policy.
 999  *
1000  * @head:   Pointer to "struct tomoyo_io_buffer".
1001  * @domain: Pointer to "struct tomoyo_domain_info".
1002  *
1003  * Caller holds tomoyo_read_lock().
1004  *
1005  * Returns true on success, false otherwise.
1006  */
1007 static bool tomoyo_read_domain2(struct tomoyo_io_buffer *head,
1008                                 struct tomoyo_domain_info *domain)
1009 {
1010         list_for_each_cookie(head->r.acl, &domain->acl_info_list) {
1011                 struct tomoyo_acl_info *ptr =
1012                         list_entry(head->r.acl, typeof(*ptr), list);
1013                 if (!tomoyo_print_entry(head, ptr))
1014                         return false;
1015         }
1016         head->r.acl = NULL;
1017         return true;
1018 }
1019
1020 /**
1021  * tomoyo_read_domain - Read domain policy.
1022  *
1023  * @head: Pointer to "struct tomoyo_io_buffer".
1024  *
1025  * Caller holds tomoyo_read_lock().
1026  */
1027 static void tomoyo_read_domain(struct tomoyo_io_buffer *head)
1028 {
1029         if (head->r.eof)
1030                 return;
1031         list_for_each_cookie(head->r.domain, &tomoyo_domain_list) {
1032                 struct tomoyo_domain_info *domain =
1033                         list_entry(head->r.domain, typeof(*domain), list);
1034                 switch (head->r.step) {
1035                 case 0:
1036                         if (domain->is_deleted &&
1037                             !head->r.print_this_domain_only)
1038                                 continue;
1039                         /* Print domainname and flags. */
1040                         tomoyo_set_string(head, domain->domainname->name);
1041                         tomoyo_set_lf(head);
1042                         tomoyo_io_printf(head, "use_profile %u\n",
1043                                          domain->profile);
1044                         if (domain->quota_warned)
1045                                 tomoyo_set_string(head, "quota_exceeded\n");
1046                         if (domain->transition_failed)
1047                                 tomoyo_set_string(head, "transition_failed\n");
1048                         head->r.step++;
1049                         tomoyo_set_lf(head);
1050                         /* fall through */
1051                 case 1:
1052                         if (!tomoyo_read_domain2(head, domain))
1053                                 return;
1054                         head->r.step++;
1055                         if (!tomoyo_set_lf(head))
1056                                 return;
1057                         /* fall through */
1058                 case 2:
1059                         head->r.step = 0;
1060                         if (head->r.print_this_domain_only)
1061                                 goto done;
1062                 }
1063         }
1064  done:
1065         head->r.eof = true;
1066 }
1067
1068 /**
1069  * tomoyo_write_domain_profile - Assign profile for specified domain.
1070  *
1071  * @head: Pointer to "struct tomoyo_io_buffer".
1072  *
1073  * Returns 0 on success, -EINVAL otherwise.
1074  *
1075  * This is equivalent to doing
1076  *
1077  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1078  *     /usr/sbin/tomoyo-loadpolicy -d
1079  *
1080  * Caller holds tomoyo_read_lock().
1081  */
1082 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1083 {
1084         char *data = head->write_buf;
1085         char *cp = strchr(data, ' ');
1086         struct tomoyo_domain_info *domain;
1087         unsigned long profile;
1088
1089         if (!cp)
1090                 return -EINVAL;
1091         *cp = '\0';
1092         domain = tomoyo_find_domain(cp + 1);
1093         if (strict_strtoul(data, 10, &profile))
1094                 return -EINVAL;
1095         if (domain && profile < TOMOYO_MAX_PROFILES
1096             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1097                 domain->profile = (u8) profile;
1098         return 0;
1099 }
1100
1101 /**
1102  * tomoyo_read_domain_profile - Read only domainname and profile.
1103  *
1104  * @head: Pointer to "struct tomoyo_io_buffer".
1105  *
1106  * Returns list of profile number and domainname pairs.
1107  *
1108  * This is equivalent to doing
1109  *
1110  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1111  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1112  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1113  *     print $2 " " domainname; domainname = ""; } } ; '
1114  *
1115  * Caller holds tomoyo_read_lock().
1116  */
1117 static void tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1118 {
1119         if (head->r.eof)
1120                 return;
1121         list_for_each_cookie(head->r.domain, &tomoyo_domain_list) {
1122                 struct tomoyo_domain_info *domain =
1123                         list_entry(head->r.domain, typeof(*domain), list);
1124                 if (domain->is_deleted)
1125                         continue;
1126                 if (!tomoyo_flush(head))
1127                         return;
1128                 tomoyo_io_printf(head, "%u ", domain->profile);
1129                 tomoyo_set_string(head, domain->domainname->name);
1130                 tomoyo_set_lf(head);
1131         }
1132         head->r.eof = true;
1133 }
1134
1135 /**
1136  * tomoyo_write_pid: Specify PID to obtain domainname.
1137  *
1138  * @head: Pointer to "struct tomoyo_io_buffer".
1139  *
1140  * Returns 0.
1141  */
1142 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1143 {
1144         head->r.eof = false;
1145         return 0;
1146 }
1147
1148 /**
1149  * tomoyo_read_pid - Get domainname of the specified PID.
1150  *
1151  * @head: Pointer to "struct tomoyo_io_buffer".
1152  *
1153  * Returns the domainname which the specified PID is in on success,
1154  * empty string otherwise.
1155  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1156  * using read()/write() interface rather than sysctl() interface.
1157  */
1158 static void tomoyo_read_pid(struct tomoyo_io_buffer *head)
1159 {
1160         char *buf = head->write_buf;
1161         bool global_pid = false;
1162         unsigned int pid;
1163         struct task_struct *p;
1164         struct tomoyo_domain_info *domain = NULL;
1165
1166         /* Accessing write_buf is safe because head->io_sem is held. */
1167         if (!buf) {
1168                 head->r.eof = true;
1169                 return; /* Do nothing if open(O_RDONLY). */
1170         }
1171         if (head->r.w_pos || head->r.eof)
1172                 return;
1173         head->r.eof = true;
1174         if (tomoyo_str_starts(&buf, "global-pid "))
1175                 global_pid = true;
1176         pid = (unsigned int) simple_strtoul(buf, NULL, 10);
1177         rcu_read_lock();
1178         read_lock(&tasklist_lock);
1179         if (global_pid)
1180                 p = find_task_by_pid_ns(pid, &init_pid_ns);
1181         else
1182                 p = find_task_by_vpid(pid);
1183         if (p)
1184                 domain = tomoyo_real_domain(p);
1185         read_unlock(&tasklist_lock);
1186         rcu_read_unlock();
1187         if (!domain)
1188                 return;
1189         tomoyo_io_printf(head, "%u %u ", pid, domain->profile);
1190         tomoyo_set_string(head, domain->domainname->name);
1191 }
1192
1193 static const char *tomoyo_transition_type[TOMOYO_MAX_TRANSITION_TYPE] = {
1194         [TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE] = "no_initialize_domain",
1195         [TOMOYO_TRANSITION_CONTROL_INITIALIZE]    = "initialize_domain",
1196         [TOMOYO_TRANSITION_CONTROL_NO_KEEP]       = "no_keep_domain",
1197         [TOMOYO_TRANSITION_CONTROL_KEEP]          = "keep_domain",
1198 };
1199
1200 static const char *tomoyo_group_name[TOMOYO_MAX_GROUP] = {
1201         [TOMOYO_PATH_GROUP]   = "path_group ",
1202         [TOMOYO_NUMBER_GROUP] = "number_group ",
1203 };
1204
1205 /**
1206  * tomoyo_write_exception - Write exception policy.
1207  *
1208  * @head: Pointer to "struct tomoyo_io_buffer".
1209  *
1210  * Returns 0 on success, negative value otherwise.
1211  *
1212  * Caller holds tomoyo_read_lock().
1213  */
1214 static int tomoyo_write_exception(struct tomoyo_io_buffer *head)
1215 {
1216         char *data = head->write_buf;
1217         bool is_delete = tomoyo_str_starts(&data, "delete ");
1218         u8 i;
1219         static const struct {
1220                 const char *keyword;
1221                 int (*write) (char *, const bool);
1222         } tomoyo_callback[1] = {
1223                 { "aggregator ", tomoyo_write_aggregator },
1224         };
1225
1226         for (i = 0; i < TOMOYO_MAX_TRANSITION_TYPE; i++)
1227                 if (tomoyo_str_starts(&data, tomoyo_transition_type[i]))
1228                         return tomoyo_write_transition_control(data, is_delete,
1229                                                                i);
1230         for (i = 0; i < 1; i++)
1231                 if (tomoyo_str_starts(&data, tomoyo_callback[i].keyword))
1232                         return tomoyo_callback[i].write(data, is_delete);
1233         for (i = 0; i < TOMOYO_MAX_GROUP; i++)
1234                 if (tomoyo_str_starts(&data, tomoyo_group_name[i]))
1235                         return tomoyo_write_group(data, is_delete, i);
1236         return -EINVAL;
1237 }
1238
1239 /**
1240  * tomoyo_read_group - Read "struct tomoyo_path_group"/"struct tomoyo_number_group" list.
1241  *
1242  * @head: Pointer to "struct tomoyo_io_buffer".
1243  * @idx:  Index number.
1244  *
1245  * Returns true on success, false otherwise.
1246  *
1247  * Caller holds tomoyo_read_lock().
1248  */
1249 static bool tomoyo_read_group(struct tomoyo_io_buffer *head, const int idx)
1250 {
1251         list_for_each_cookie(head->r.group, &tomoyo_group_list[idx]) {
1252                 struct tomoyo_group *group =
1253                         list_entry(head->r.group, typeof(*group), head.list);
1254                 list_for_each_cookie(head->r.acl, &group->member_list) {
1255                         struct tomoyo_acl_head *ptr =
1256                                 list_entry(head->r.acl, typeof(*ptr), list);
1257                         if (ptr->is_deleted)
1258                                 continue;
1259                         if (!tomoyo_flush(head))
1260                                 return false;
1261                         tomoyo_set_string(head, tomoyo_group_name[idx]);
1262                         tomoyo_set_string(head, group->group_name->name);
1263                         if (idx == TOMOYO_PATH_GROUP) {
1264                                 tomoyo_set_space(head);
1265                                 tomoyo_set_string(head, container_of
1266                                                (ptr, struct tomoyo_path_group,
1267                                                 head)->member_name->name);
1268                         } else if (idx == TOMOYO_NUMBER_GROUP) {
1269                                 tomoyo_print_number_union(head, &container_of
1270                                                           (ptr,
1271                                                    struct tomoyo_number_group,
1272                                                            head)->number);
1273                         }
1274                         tomoyo_set_lf(head);
1275                 }
1276                 head->r.acl = NULL;
1277         }
1278         head->r.group = NULL;
1279         return true;
1280 }
1281
1282 /**
1283  * tomoyo_read_policy - Read "struct tomoyo_..._entry" list.
1284  *
1285  * @head: Pointer to "struct tomoyo_io_buffer".
1286  * @idx:  Index number.
1287  *
1288  * Returns true on success, false otherwise.
1289  *
1290  * Caller holds tomoyo_read_lock().
1291  */
1292 static bool tomoyo_read_policy(struct tomoyo_io_buffer *head, const int idx)
1293 {
1294         list_for_each_cookie(head->r.acl, &tomoyo_policy_list[idx]) {
1295                 struct tomoyo_acl_head *acl =
1296                         container_of(head->r.acl, typeof(*acl), list);
1297                 if (acl->is_deleted)
1298                         continue;
1299                 if (!tomoyo_flush(head))
1300                         return false;
1301                 switch (idx) {
1302                 case TOMOYO_ID_TRANSITION_CONTROL:
1303                         {
1304                                 struct tomoyo_transition_control *ptr =
1305                                         container_of(acl, typeof(*ptr), head);
1306                                 tomoyo_set_string(head,
1307                                                   tomoyo_transition_type
1308                                                   [ptr->type]);
1309                                 if (ptr->program)
1310                                         tomoyo_set_string(head,
1311                                                           ptr->program->name);
1312                                 if (ptr->program && ptr->domainname)
1313                                         tomoyo_set_string(head, " from ");
1314                                 if (ptr->domainname)
1315                                         tomoyo_set_string(head,
1316                                                           ptr->domainname->
1317                                                           name);
1318                         }
1319                         break;
1320                 case TOMOYO_ID_AGGREGATOR:
1321                         {
1322                                 struct tomoyo_aggregator *ptr =
1323                                         container_of(acl, typeof(*ptr), head);
1324                                 tomoyo_set_string(head, "aggregator ");
1325                                 tomoyo_set_string(head,
1326                                                   ptr->original_name->name);
1327                                 tomoyo_set_space(head);
1328                                 tomoyo_set_string(head,
1329                                                ptr->aggregated_name->name);
1330                         }
1331                         break;
1332                 default:
1333                         continue;
1334                 }
1335                 tomoyo_set_lf(head);
1336         }
1337         head->r.acl = NULL;
1338         return true;
1339 }
1340
1341 /**
1342  * tomoyo_read_exception - Read exception policy.
1343  *
1344  * @head: Pointer to "struct tomoyo_io_buffer".
1345  *
1346  * Caller holds tomoyo_read_lock().
1347  */
1348 static void tomoyo_read_exception(struct tomoyo_io_buffer *head)
1349 {
1350         if (head->r.eof)
1351                 return;
1352         while (head->r.step < TOMOYO_MAX_POLICY &&
1353                tomoyo_read_policy(head, head->r.step))
1354                 head->r.step++;
1355         if (head->r.step < TOMOYO_MAX_POLICY)
1356                 return;
1357         while (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP &&
1358                tomoyo_read_group(head, head->r.step - TOMOYO_MAX_POLICY))
1359                 head->r.step++;
1360         if (head->r.step < TOMOYO_MAX_POLICY + TOMOYO_MAX_GROUP)
1361                 return;
1362         head->r.eof = true;
1363 }
1364
1365 /**
1366  * tomoyo_print_header - Get header line of audit log.
1367  *
1368  * @r: Pointer to "struct tomoyo_request_info".
1369  *
1370  * Returns string representation.
1371  *
1372  * This function uses kmalloc(), so caller must kfree() if this function
1373  * didn't return NULL.
1374  */
1375 static char *tomoyo_print_header(struct tomoyo_request_info *r)
1376 {
1377         struct timeval tv;
1378         const pid_t gpid = task_pid_nr(current);
1379         static const int tomoyo_buffer_len = 4096;
1380         char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
1381         pid_t ppid;
1382         if (!buffer)
1383                 return NULL;
1384         do_gettimeofday(&tv);
1385         rcu_read_lock();
1386         ppid = task_tgid_vnr(current->real_parent);
1387         rcu_read_unlock();
1388         snprintf(buffer, tomoyo_buffer_len - 1,
1389                  "#timestamp=%lu profile=%u mode=%s (global-pid=%u)"
1390                  " task={ pid=%u ppid=%u uid=%u gid=%u euid=%u"
1391                  " egid=%u suid=%u sgid=%u fsuid=%u fsgid=%u }",
1392                  tv.tv_sec, r->profile, tomoyo_mode[r->mode], gpid,
1393                  task_tgid_vnr(current), ppid,
1394                  current_uid(), current_gid(), current_euid(),
1395                  current_egid(), current_suid(), current_sgid(),
1396                  current_fsuid(), current_fsgid());
1397         return buffer;
1398 }
1399
1400 /**
1401  * tomoyo_init_audit_log - Allocate buffer for audit logs.
1402  *
1403  * @len: Required size.
1404  * @r:   Pointer to "struct tomoyo_request_info".
1405  *
1406  * Returns pointer to allocated memory.
1407  *
1408  * The @len is updated to add the header lines' size on success.
1409  *
1410  * This function uses kzalloc(), so caller must kfree() if this function
1411  * didn't return NULL.
1412  */
1413 static char *tomoyo_init_audit_log(int *len, struct tomoyo_request_info *r)
1414 {
1415         char *buf = NULL;
1416         const char *header;
1417         const char *domainname;
1418         if (!r->domain)
1419                 r->domain = tomoyo_domain();
1420         domainname = r->domain->domainname->name;
1421         header = tomoyo_print_header(r);
1422         if (!header)
1423                 return NULL;
1424         *len += strlen(domainname) + strlen(header) + 10;
1425         buf = kzalloc(*len, GFP_NOFS);
1426         if (buf)
1427                 snprintf(buf, (*len) - 1, "%s\n%s\n", header, domainname);
1428         kfree(header);
1429         return buf;
1430 }
1431
1432 /* Wait queue for tomoyo_query_list. */
1433 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_query_wait);
1434
1435 /* Lock for manipulating tomoyo_query_list. */
1436 static DEFINE_SPINLOCK(tomoyo_query_list_lock);
1437
1438 /* Structure for query. */
1439 struct tomoyo_query {
1440         struct list_head list;
1441         char *query;
1442         int query_len;
1443         unsigned int serial;
1444         int timer;
1445         int answer;
1446 };
1447
1448 /* The list for "struct tomoyo_query". */
1449 static LIST_HEAD(tomoyo_query_list);
1450
1451 /*
1452  * Number of "struct file" referring /sys/kernel/security/tomoyo/query
1453  * interface.
1454  */
1455 static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
1456
1457 /**
1458  * tomoyo_supervisor - Ask for the supervisor's decision.
1459  *
1460  * @r:       Pointer to "struct tomoyo_request_info".
1461  * @fmt:     The printf()'s format string, followed by parameters.
1462  *
1463  * Returns 0 if the supervisor decided to permit the access request which
1464  * violated the policy in enforcing mode, TOMOYO_RETRY_REQUEST if the
1465  * supervisor decided to retry the access request which violated the policy in
1466  * enforcing mode, 0 if it is not in enforcing mode, -EPERM otherwise.
1467  */
1468 int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
1469 {
1470         va_list args;
1471         int error = -EPERM;
1472         int pos;
1473         int len;
1474         static unsigned int tomoyo_serial;
1475         struct tomoyo_query *entry = NULL;
1476         bool quota_exceeded = false;
1477         char *header;
1478         switch (r->mode) {
1479                 char *buffer;
1480         case TOMOYO_CONFIG_LEARNING:
1481                 if (!tomoyo_domain_quota_is_ok(r))
1482                         return 0;
1483                 va_start(args, fmt);
1484                 len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 4;
1485                 va_end(args);
1486                 buffer = kmalloc(len, GFP_NOFS);
1487                 if (!buffer)
1488                         return 0;
1489                 va_start(args, fmt);
1490                 vsnprintf(buffer, len - 1, fmt, args);
1491                 va_end(args);
1492                 tomoyo_normalize_line(buffer);
1493                 tomoyo_write_domain2(buffer, r->domain, false);
1494                 kfree(buffer);
1495                 /* fall through */
1496         case TOMOYO_CONFIG_PERMISSIVE:
1497                 return 0;
1498         }
1499         if (!r->domain)
1500                 r->domain = tomoyo_domain();
1501         if (!atomic_read(&tomoyo_query_observers))
1502                 return -EPERM;
1503         va_start(args, fmt);
1504         len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 32;
1505         va_end(args);
1506         header = tomoyo_init_audit_log(&len, r);
1507         if (!header)
1508                 goto out;
1509         entry = kzalloc(sizeof(*entry), GFP_NOFS);
1510         if (!entry)
1511                 goto out;
1512         entry->query = kzalloc(len, GFP_NOFS);
1513         if (!entry->query)
1514                 goto out;
1515         len = ksize(entry->query);
1516         spin_lock(&tomoyo_query_list_lock);
1517         if (tomoyo_quota_for_query && tomoyo_query_memory_size + len +
1518             sizeof(*entry) >= tomoyo_quota_for_query) {
1519                 quota_exceeded = true;
1520         } else {
1521                 tomoyo_query_memory_size += len + sizeof(*entry);
1522                 entry->serial = tomoyo_serial++;
1523         }
1524         spin_unlock(&tomoyo_query_list_lock);
1525         if (quota_exceeded)
1526                 goto out;
1527         pos = snprintf(entry->query, len - 1, "Q%u-%hu\n%s",
1528                        entry->serial, r->retry, header);
1529         kfree(header);
1530         header = NULL;
1531         va_start(args, fmt);
1532         vsnprintf(entry->query + pos, len - 1 - pos, fmt, args);
1533         entry->query_len = strlen(entry->query) + 1;
1534         va_end(args);
1535         spin_lock(&tomoyo_query_list_lock);
1536         list_add_tail(&entry->list, &tomoyo_query_list);
1537         spin_unlock(&tomoyo_query_list_lock);
1538         /* Give 10 seconds for supervisor's opinion. */
1539         for (entry->timer = 0;
1540              atomic_read(&tomoyo_query_observers) && entry->timer < 100;
1541              entry->timer++) {
1542                 wake_up(&tomoyo_query_wait);
1543                 set_current_state(TASK_INTERRUPTIBLE);
1544                 schedule_timeout(HZ / 10);
1545                 if (entry->answer)
1546                         break;
1547         }
1548         spin_lock(&tomoyo_query_list_lock);
1549         list_del(&entry->list);
1550         tomoyo_query_memory_size -= len + sizeof(*entry);
1551         spin_unlock(&tomoyo_query_list_lock);
1552         switch (entry->answer) {
1553         case 3: /* Asked to retry by administrator. */
1554                 error = TOMOYO_RETRY_REQUEST;
1555                 r->retry++;
1556                 break;
1557         case 1:
1558                 /* Granted by administrator. */
1559                 error = 0;
1560                 break;
1561         case 0:
1562                 /* Timed out. */
1563                 break;
1564         default:
1565                 /* Rejected by administrator. */
1566                 break;
1567         }
1568  out:
1569         if (entry)
1570                 kfree(entry->query);
1571         kfree(entry);
1572         kfree(header);
1573         return error;
1574 }
1575
1576 /**
1577  * tomoyo_poll_query - poll() for /sys/kernel/security/tomoyo/query.
1578  *
1579  * @file: Pointer to "struct file".
1580  * @wait: Pointer to "poll_table".
1581  *
1582  * Returns POLLIN | POLLRDNORM when ready to read, 0 otherwise.
1583  *
1584  * Waits for access requests which violated policy in enforcing mode.
1585  */
1586 static int tomoyo_poll_query(struct file *file, poll_table *wait)
1587 {
1588         struct list_head *tmp;
1589         bool found = false;
1590         u8 i;
1591         for (i = 0; i < 2; i++) {
1592                 spin_lock(&tomoyo_query_list_lock);
1593                 list_for_each(tmp, &tomoyo_query_list) {
1594                         struct tomoyo_query *ptr =
1595                                 list_entry(tmp, typeof(*ptr), list);
1596                         if (ptr->answer)
1597                                 continue;
1598                         found = true;
1599                         break;
1600                 }
1601                 spin_unlock(&tomoyo_query_list_lock);
1602                 if (found)
1603                         return POLLIN | POLLRDNORM;
1604                 if (i)
1605                         break;
1606                 poll_wait(file, &tomoyo_query_wait, wait);
1607         }
1608         return 0;
1609 }
1610
1611 /**
1612  * tomoyo_read_query - Read access requests which violated policy in enforcing mode.
1613  *
1614  * @head: Pointer to "struct tomoyo_io_buffer".
1615  */
1616 static void tomoyo_read_query(struct tomoyo_io_buffer *head)
1617 {
1618         struct list_head *tmp;
1619         int pos = 0;
1620         int len = 0;
1621         char *buf;
1622         if (head->r.w_pos)
1623                 return;
1624         if (head->read_buf) {
1625                 kfree(head->read_buf);
1626                 head->read_buf = NULL;
1627         }
1628         spin_lock(&tomoyo_query_list_lock);
1629         list_for_each(tmp, &tomoyo_query_list) {
1630                 struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1631                 if (ptr->answer)
1632                         continue;
1633                 if (pos++ != head->r.query_index)
1634                         continue;
1635                 len = ptr->query_len;
1636                 break;
1637         }
1638         spin_unlock(&tomoyo_query_list_lock);
1639         if (!len) {
1640                 head->r.query_index = 0;
1641                 return;
1642         }
1643         buf = kzalloc(len, GFP_NOFS);
1644         if (!buf)
1645                 return;
1646         pos = 0;
1647         spin_lock(&tomoyo_query_list_lock);
1648         list_for_each(tmp, &tomoyo_query_list) {
1649                 struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1650                 if (ptr->answer)
1651                         continue;
1652                 if (pos++ != head->r.query_index)
1653                         continue;
1654                 /*
1655                  * Some query can be skipped because tomoyo_query_list
1656                  * can change, but I don't care.
1657                  */
1658                 if (len == ptr->query_len)
1659                         memmove(buf, ptr->query, len);
1660                 break;
1661         }
1662         spin_unlock(&tomoyo_query_list_lock);
1663         if (buf[0]) {
1664                 head->read_buf = buf;
1665                 head->r.w[head->r.w_pos++] = buf;
1666                 head->r.query_index++;
1667         } else {
1668                 kfree(buf);
1669         }
1670 }
1671
1672 /**
1673  * tomoyo_write_answer - Write the supervisor's decision.
1674  *
1675  * @head: Pointer to "struct tomoyo_io_buffer".
1676  *
1677  * Returns 0 on success, -EINVAL otherwise.
1678  */
1679 static int tomoyo_write_answer(struct tomoyo_io_buffer *head)
1680 {
1681         char *data = head->write_buf;
1682         struct list_head *tmp;
1683         unsigned int serial;
1684         unsigned int answer;
1685         spin_lock(&tomoyo_query_list_lock);
1686         list_for_each(tmp, &tomoyo_query_list) {
1687                 struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1688                 ptr->timer = 0;
1689         }
1690         spin_unlock(&tomoyo_query_list_lock);
1691         if (sscanf(data, "A%u=%u", &serial, &answer) != 2)
1692                 return -EINVAL;
1693         spin_lock(&tomoyo_query_list_lock);
1694         list_for_each(tmp, &tomoyo_query_list) {
1695                 struct tomoyo_query *ptr = list_entry(tmp, typeof(*ptr), list);
1696                 if (ptr->serial != serial)
1697                         continue;
1698                 if (!ptr->answer)
1699                         ptr->answer = answer;
1700                 break;
1701         }
1702         spin_unlock(&tomoyo_query_list_lock);
1703         return 0;
1704 }
1705
1706 /**
1707  * tomoyo_read_version: Get version.
1708  *
1709  * @head: Pointer to "struct tomoyo_io_buffer".
1710  *
1711  * Returns version information.
1712  */
1713 static void tomoyo_read_version(struct tomoyo_io_buffer *head)
1714 {
1715         if (!head->r.eof) {
1716                 tomoyo_io_printf(head, "2.3.0");
1717                 head->r.eof = true;
1718         }
1719 }
1720
1721 /**
1722  * tomoyo_read_self_domain - Get the current process's domainname.
1723  *
1724  * @head: Pointer to "struct tomoyo_io_buffer".
1725  *
1726  * Returns the current process's domainname.
1727  */
1728 static void tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1729 {
1730         if (!head->r.eof) {
1731                 /*
1732                  * tomoyo_domain()->domainname != NULL
1733                  * because every process belongs to a domain and
1734                  * the domain's name cannot be NULL.
1735                  */
1736                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1737                 head->r.eof = true;
1738         }
1739 }
1740
1741 /**
1742  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1743  *
1744  * @type: Type of interface.
1745  * @file: Pointer to "struct file".
1746  *
1747  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1748  *
1749  * Caller acquires tomoyo_read_lock().
1750  */
1751 int tomoyo_open_control(const u8 type, struct file *file)
1752 {
1753         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_NOFS);
1754
1755         if (!head)
1756                 return -ENOMEM;
1757         mutex_init(&head->io_sem);
1758         head->type = type;
1759         switch (type) {
1760         case TOMOYO_DOMAINPOLICY:
1761                 /* /sys/kernel/security/tomoyo/domain_policy */
1762                 head->write = tomoyo_write_domain;
1763                 head->read = tomoyo_read_domain;
1764                 break;
1765         case TOMOYO_EXCEPTIONPOLICY:
1766                 /* /sys/kernel/security/tomoyo/exception_policy */
1767                 head->write = tomoyo_write_exception;
1768                 head->read = tomoyo_read_exception;
1769                 break;
1770         case TOMOYO_SELFDOMAIN:
1771                 /* /sys/kernel/security/tomoyo/self_domain */
1772                 head->read = tomoyo_read_self_domain;
1773                 break;
1774         case TOMOYO_DOMAIN_STATUS:
1775                 /* /sys/kernel/security/tomoyo/.domain_status */
1776                 head->write = tomoyo_write_domain_profile;
1777                 head->read = tomoyo_read_domain_profile;
1778                 break;
1779         case TOMOYO_PROCESS_STATUS:
1780                 /* /sys/kernel/security/tomoyo/.process_status */
1781                 head->write = tomoyo_write_pid;
1782                 head->read = tomoyo_read_pid;
1783                 break;
1784         case TOMOYO_VERSION:
1785                 /* /sys/kernel/security/tomoyo/version */
1786                 head->read = tomoyo_read_version;
1787                 head->readbuf_size = 128;
1788                 break;
1789         case TOMOYO_MEMINFO:
1790                 /* /sys/kernel/security/tomoyo/meminfo */
1791                 head->write = tomoyo_write_memory_quota;
1792                 head->read = tomoyo_read_memory_counter;
1793                 head->readbuf_size = 512;
1794                 break;
1795         case TOMOYO_PROFILE:
1796                 /* /sys/kernel/security/tomoyo/profile */
1797                 head->write = tomoyo_write_profile;
1798                 head->read = tomoyo_read_profile;
1799                 break;
1800         case TOMOYO_QUERY: /* /sys/kernel/security/tomoyo/query */
1801                 head->poll = tomoyo_poll_query;
1802                 head->write = tomoyo_write_answer;
1803                 head->read = tomoyo_read_query;
1804                 break;
1805         case TOMOYO_MANAGER:
1806                 /* /sys/kernel/security/tomoyo/manager */
1807                 head->write = tomoyo_write_manager;
1808                 head->read = tomoyo_read_manager;
1809                 break;
1810         }
1811         if (!(file->f_mode & FMODE_READ)) {
1812                 /*
1813                  * No need to allocate read_buf since it is not opened
1814                  * for reading.
1815                  */
1816                 head->read = NULL;
1817                 head->poll = NULL;
1818         } else if (!head->poll) {
1819                 /* Don't allocate read_buf for poll() access. */
1820                 if (!head->readbuf_size)
1821                         head->readbuf_size = 4096 * 2;
1822                 head->read_buf = kzalloc(head->readbuf_size, GFP_NOFS);
1823                 if (!head->read_buf) {
1824                         kfree(head);
1825                         return -ENOMEM;
1826                 }
1827         }
1828         if (!(file->f_mode & FMODE_WRITE)) {
1829                 /*
1830                  * No need to allocate write_buf since it is not opened
1831                  * for writing.
1832                  */
1833                 head->write = NULL;
1834         } else if (head->write) {
1835                 head->writebuf_size = 4096 * 2;
1836                 head->write_buf = kzalloc(head->writebuf_size, GFP_NOFS);
1837                 if (!head->write_buf) {
1838                         kfree(head->read_buf);
1839                         kfree(head);
1840                         return -ENOMEM;
1841                 }
1842         }
1843         if (type != TOMOYO_QUERY)
1844                 head->reader_idx = tomoyo_read_lock();
1845         file->private_data = head;
1846         /*
1847          * If the file is /sys/kernel/security/tomoyo/query , increment the
1848          * observer counter.
1849          * The obserber counter is used by tomoyo_supervisor() to see if
1850          * there is some process monitoring /sys/kernel/security/tomoyo/query.
1851          */
1852         if (type == TOMOYO_QUERY)
1853                 atomic_inc(&tomoyo_query_observers);
1854         return 0;
1855 }
1856
1857 /**
1858  * tomoyo_poll_control - poll() for /sys/kernel/security/tomoyo/ interface.
1859  *
1860  * @file: Pointer to "struct file".
1861  * @wait: Pointer to "poll_table".
1862  *
1863  * Waits for read readiness.
1864  * /sys/kernel/security/tomoyo/query is handled by /usr/sbin/tomoyo-queryd .
1865  */
1866 int tomoyo_poll_control(struct file *file, poll_table *wait)
1867 {
1868         struct tomoyo_io_buffer *head = file->private_data;
1869         if (!head->poll)
1870                 return -ENOSYS;
1871         return head->poll(file, wait);
1872 }
1873
1874 /**
1875  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1876  *
1877  * @head:       Pointer to "struct tomoyo_io_buffer".
1878  * @buffer:     Poiner to buffer to write to.
1879  * @buffer_len: Size of @buffer.
1880  *
1881  * Returns bytes read on success, negative value otherwise.
1882  *
1883  * Caller holds tomoyo_read_lock().
1884  */
1885 int tomoyo_read_control(struct tomoyo_io_buffer *head, char __user *buffer,
1886                         const int buffer_len)
1887 {
1888         int len;
1889
1890         if (!head->read)
1891                 return -ENOSYS;
1892         if (mutex_lock_interruptible(&head->io_sem))
1893                 return -EINTR;
1894         head->read_user_buf = buffer;
1895         head->read_user_buf_avail = buffer_len;
1896         if (tomoyo_flush(head))
1897                 /* Call the policy handler. */
1898                 head->read(head);
1899         tomoyo_flush(head);
1900         len = head->read_user_buf - buffer;
1901         mutex_unlock(&head->io_sem);
1902         return len;
1903 }
1904
1905 /**
1906  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
1907  *
1908  * @head:       Pointer to "struct tomoyo_io_buffer".
1909  * @buffer:     Pointer to buffer to read from.
1910  * @buffer_len: Size of @buffer.
1911  *
1912  * Returns @buffer_len on success, negative value otherwise.
1913  *
1914  * Caller holds tomoyo_read_lock().
1915  */
1916 int tomoyo_write_control(struct tomoyo_io_buffer *head,
1917                          const char __user *buffer, const int buffer_len)
1918 {
1919         int error = buffer_len;
1920         int avail_len = buffer_len;
1921         char *cp0 = head->write_buf;
1922
1923         if (!head->write)
1924                 return -ENOSYS;
1925         if (!access_ok(VERIFY_READ, buffer, buffer_len))
1926                 return -EFAULT;
1927         /* Don't allow updating policies by non manager programs. */
1928         if (head->write != tomoyo_write_pid &&
1929             head->write != tomoyo_write_domain && !tomoyo_manager())
1930                 return -EPERM;
1931         if (mutex_lock_interruptible(&head->io_sem))
1932                 return -EINTR;
1933         /* Read a line and dispatch it to the policy handler. */
1934         while (avail_len > 0) {
1935                 char c;
1936                 if (head->w.avail >= head->writebuf_size - 1) {
1937                         error = -ENOMEM;
1938                         break;
1939                 } else if (get_user(c, buffer)) {
1940                         error = -EFAULT;
1941                         break;
1942                 }
1943                 buffer++;
1944                 avail_len--;
1945                 cp0[head->w.avail++] = c;
1946                 if (c != '\n')
1947                         continue;
1948                 cp0[head->w.avail - 1] = '\0';
1949                 head->w.avail = 0;
1950                 tomoyo_normalize_line(cp0);
1951                 head->write(head);
1952         }
1953         mutex_unlock(&head->io_sem);
1954         return error;
1955 }
1956
1957 /**
1958  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
1959  *
1960  * @head: Pointer to "struct tomoyo_io_buffer".
1961  *
1962  * Releases memory and returns 0.
1963  *
1964  * Caller looses tomoyo_read_lock().
1965  */
1966 int tomoyo_close_control(struct tomoyo_io_buffer *head)
1967 {
1968         const bool is_write = !!head->write_buf;
1969
1970         /*
1971          * If the file is /sys/kernel/security/tomoyo/query , decrement the
1972          * observer counter.
1973          */
1974         if (head->type == TOMOYO_QUERY)
1975                 atomic_dec(&tomoyo_query_observers);
1976         else
1977                 tomoyo_read_unlock(head->reader_idx);
1978         /* Release memory used for policy I/O. */
1979         kfree(head->read_buf);
1980         head->read_buf = NULL;
1981         kfree(head->write_buf);
1982         head->write_buf = NULL;
1983         kfree(head);
1984         if (is_write)
1985                 tomoyo_run_gc();
1986         return 0;
1987 }
1988
1989 /**
1990  * tomoyo_check_profile - Check all profiles currently assigned to domains are defined.
1991  */
1992 void tomoyo_check_profile(void)
1993 {
1994         struct tomoyo_domain_info *domain;
1995         const int idx = tomoyo_read_lock();
1996         tomoyo_policy_loaded = true;
1997         /* Check all profiles currently assigned to domains are defined. */
1998         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1999                 const u8 profile = domain->profile;
2000                 if (tomoyo_profile_ptr[profile])
2001                         continue;
2002                 printk(KERN_ERR "You need to define profile %u before using it.\n",
2003                        profile);
2004                 printk(KERN_ERR "Please see http://tomoyo.sourceforge.jp/2.3/ "
2005                        "for more information.\n");
2006                 panic("Profile %u (used by '%s') not defined.\n",
2007                       profile, domain->domainname->name);
2008         }
2009         tomoyo_read_unlock(idx);
2010         if (tomoyo_profile_version != 20090903) {
2011                 printk(KERN_ERR "You need to install userland programs for "
2012                        "TOMOYO 2.3 and initialize policy configuration.\n");
2013                 printk(KERN_ERR "Please see http://tomoyo.sourceforge.jp/2.3/ "
2014                        "for more information.\n");
2015                 panic("Profile version %u is not supported.\n",
2016                       tomoyo_profile_version);
2017         }
2018         printk(KERN_INFO "TOMOYO: 2.3.0\n");
2019         printk(KERN_INFO "Mandatory Access Control activated.\n");
2020 }