lib/ext2fs/ext_attr.c

   1 /*
   2  * ext_attr.c --- extended attribute blocks
   3  *
   4  * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   5  *
   6  * Copyright (C) 2002 Theodore Ts'o.
   7  *
   8  * %Begin-Header%
   9  * This file may be redistributed under the terms of the GNU Library
  10  * General Public License, version 2.
  11  * %End-Header%
  12  */
  13
  14 #include "config.h"
  15 #include <stdio.h>
  16 #if HAVE_UNISTD_H
  17 #include <unistd.h>
  18 #endif
  19 #include <string.h>
  20 #include <time.h>
  21
  22 #include "ext2_fs.h"
  23 #include "ext2_ext_attr.h"
  24
  25 #include "ext2fs.h"
  26
  27 #define NAME_HASH_SHIFT 5
  28 #define VALUE_HASH_SHIFT 16
  29
  30 /*
  31  * ext2_xattr_hash_entry()
  32  *
  33  * Compute the hash of an extended attribute.
  34  */
  35 __u32 ext2fs_ext_attr_hash_entry(struct ext2_ext_attr_entry *entry, void *data)
  36 {
  37         __u32 hash = 0;
  38         char *name = ((char *) entry) + sizeof(struct ext2_ext_attr_entry);
  39         int n;
  40
  41         for (n = 0; n < entry->e_name_len; n++) {
  42                 hash = (hash << NAME_HASH_SHIFT) ^
  43                        (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
  44                        *name++;
  45         }
  46
  47         /* The hash needs to be calculated on the data in little-endian. */
  48         if (entry->e_value_block == 0 && entry->e_value_size != 0) {
  49                 __u32 *value = (__u32 *)data;
  50                 for (n = (entry->e_value_size + EXT2_EXT_ATTR_ROUND) >>
  51                          EXT2_EXT_ATTR_PAD_BITS; n; n--) {
  52                         hash = (hash << VALUE_HASH_SHIFT) ^
  53                                (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
  54                                ext2fs_le32_to_cpu(*value++);
  55                 }
  56         }
  57
  58         return hash;
  59 }
  60
  61 #undef NAME_HASH_SHIFT
  62 #undef VALUE_HASH_SHIFT
  63
  64 errcode_t ext2fs_read_ext_attr3(ext2_filsys fs, blk64_t block, void *buf,
  65                                 ext2_ino_t inum)
  66 {
  67         errcode_t       retval;
  68
  69         retval = io_channel_read_blk64(fs->io, block, 1, buf);
  70         if (retval)
  71                 return retval;
  72
  73         if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
  74             !ext2fs_ext_attr_block_csum_verify(fs, inum, block, buf))
  75                 retval = EXT2_ET_EXT_ATTR_CSUM_INVALID;
  76
  77 #ifdef WORDS_BIGENDIAN
  78         ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
  79 #endif
  80
  81         return retval;
  82 }
  83
  84 errcode_t ext2fs_read_ext_attr2(ext2_filsys fs, blk64_t block, void *buf)
  85 {
  86         return ext2fs_read_ext_attr3(fs, block, buf, 0);
  87 }
  88
  89 errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
  90 {
  91         return ext2fs_read_ext_attr2(fs, block, buf);
  92 }
  93
  94 errcode_t ext2fs_write_ext_attr3(ext2_filsys fs, blk64_t block, void *inbuf,
  95                                  ext2_ino_t inum)
  96 {
  97         errcode_t       retval;
  98         char            *write_buf;
  99
 100 #ifdef WORDS_BIGENDIAN
 101         retval = ext2fs_get_mem(fs->blocksize, &write_buf);
 102         if (retval)
 103                 return retval;
 104         ext2fs_swap_ext_attr(write_buf, inbuf, fs->blocksize, 1);
 105 #else
 106         write_buf = (char *) inbuf;
 107 #endif
 108
 109         retval = ext2fs_ext_attr_block_csum_set(fs, inum, block,
 110                         (struct ext2_ext_attr_header *)write_buf);
 111         if (retval)
 112                 return retval;
 113
 114         retval = io_channel_write_blk64(fs->io, block, 1, write_buf);
 115 #ifdef WORDS_BIGENDIAN
 116         ext2fs_free_mem(&write_buf);
 117 #endif
 118         if (!retval)
 119                 ext2fs_mark_changed(fs);
 120         return retval;
 121 }
 122
 123 errcode_t ext2fs_write_ext_attr2(ext2_filsys fs, blk64_t block, void *inbuf)
 124 {
 125         return ext2fs_write_ext_attr3(fs, block, inbuf, 0);
 126 }
 127
 128 errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
 129 {
 130         return ext2fs_write_ext_attr2(fs, block, inbuf);
 131 }
 132
 133 /*
 134  * This function adjusts the reference count of the EA block.
 135  */
 136 errcode_t ext2fs_adjust_ea_refcount3(ext2_filsys fs, blk64_t blk,
 137                                     char *block_buf, int adjust,
 138                                     __u32 *newcount, ext2_ino_t inum)
 139 {
 140         errcode_t       retval;
 141         struct ext2_ext_attr_header *header;
 142         char    *buf = 0;
 143
 144         if ((blk >= ext2fs_blocks_count(fs->super)) ||
 145             (blk < fs->super->s_first_data_block))
 146                 return EXT2_ET_BAD_EA_BLOCK_NUM;
 147
 148         if (!block_buf) {
 149                 retval = ext2fs_get_mem(fs->blocksize, &buf);
 150                 if (retval)
 151                         return retval;
 152                 block_buf = buf;
 153         }
 154
 155         retval = ext2fs_read_ext_attr3(fs, blk, block_buf, inum);
 156         if (retval)
 157                 goto errout;
 158
 159         header = (struct ext2_ext_attr_header *) block_buf;
 160         header->h_refcount += adjust;
 161         if (newcount)
 162                 *newcount = header->h_refcount;
 163
 164         retval = ext2fs_write_ext_attr3(fs, blk, block_buf, inum);
 165         if (retval)
 166                 goto errout;
 167
 168 errout:
 169         if (buf)
 170                 ext2fs_free_mem(&buf);
 171         return retval;
 172 }
 173
 174 errcode_t ext2fs_adjust_ea_refcount2(ext2_filsys fs, blk64_t blk,
 175                                     char *block_buf, int adjust,
 176                                     __u32 *newcount)
 177 {
 178         return ext2fs_adjust_ea_refcount3(fs, blk, block_buf, adjust,
 179                                           newcount, 0);
 180 }
 181
 182 errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
 183                                         char *block_buf, int adjust,
 184                                         __u32 *newcount)
 185 {
 186         return ext2fs_adjust_ea_refcount2(fs, blk, block_buf, adjust,
 187                                           newcount);
 188 }
 189
 190 /* Manipulate the contents of extended attribute regions */
 191 struct ext2_xattr {
 192         char *name;
 193         void *value;
 194         size_t value_len;
 195 };
 196
 197 struct ext2_xattr_handle {
 198         ext2_filsys fs;
 199         struct ext2_xattr *attrs;
 200         size_t length, count;
 201         ext2_ino_t ino;
 202         int dirty;
 203 };
 204
 205 static errcode_t ext2fs_xattrs_expand(struct ext2_xattr_handle *h,
 206                                       unsigned int expandby)
 207 {
 208         struct ext2_xattr *new_attrs;
 209         errcode_t err;
 210
 211         err = ext2fs_get_arrayzero(h->length + expandby,
 212                                    sizeof(struct ext2_xattr), &new_attrs);
 213         if (err)
 214                 return err;
 215
 216         memcpy(new_attrs, h->attrs, h->length * sizeof(struct ext2_xattr));
 217         ext2fs_free_mem(&h->attrs);
 218         h->length += expandby;
 219         h->attrs = new_attrs;
 220
 221         return 0;
 222 }
 223
 224 struct ea_name_index {
 225         int index;
 226         const char *name;
 227 };
 228
 229 /* Keep these names sorted in order of decreasing specificity. */
 230 static struct ea_name_index ea_names[] = {
 231         {3, "system.posix_acl_default"},
 232         {2, "system.posix_acl_access"},
 233         {8, "system.richacl"},
 234         {6, "security."},
 235         {4, "trusted."},
 236         {7, "system."},
 237         {1, "user."},
 238         {0, NULL},
 239 };
 240
 241 static const char *find_ea_prefix(int index)
 242 {
 243         struct ea_name_index *e;
 244
 245         for (e = ea_names; e->name; e++)
 246                 if (e->index == index)
 247                         return e->name;
 248
 249         return NULL;
 250 }
 251
 252 static int find_ea_index(const char *fullname, char **name, int *index)
 253 {
 254         struct ea_name_index *e;
 255
 256         for (e = ea_names; e->name; e++) {
 257                 if (memcmp(fullname, e->name, strlen(e->name)) == 0) {
 258                         *name = (char *)fullname + strlen(e->name);
 259                         *index = e->index;
 260                         return 1;
 261                 }
 262         }
 263         return 0;
 264 }
 265
 266 errcode_t ext2fs_free_ext_attr(ext2_filsys fs, ext2_ino_t ino,
 267                                struct ext2_inode_large *inode)
 268 {
 269         struct ext2_ext_attr_header *header;
 270         void *block_buf = NULL;
 271         dgrp_t grp;
 272         blk64_t blk, goal;
 273         errcode_t err;
 274         struct ext2_inode_large i;
 275
 276         /* Read inode? */
 277         if (inode == NULL) {
 278                 err = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)&i,
 279                                              sizeof(struct ext2_inode_large));
 280                 if (err)
 281                         return err;
 282                 inode = &i;
 283         }
 284
 285         /* Do we already have an EA block? */
 286         blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
 287         if (blk == 0)
 288                 return 0;
 289
 290         /* Find block, zero it, write back */
 291         if ((blk < fs->super->s_first_data_block) ||
 292             (blk >= ext2fs_blocks_count(fs->super))) {
 293                 err = EXT2_ET_BAD_EA_BLOCK_NUM;
 294                 goto out;
 295         }
 296
 297         err = ext2fs_get_mem(fs->blocksize, &block_buf);
 298         if (err)
 299                 goto out;
 300
 301         err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
 302         if (err)
 303                 goto out2;
 304
 305         header = (struct ext2_ext_attr_header *) block_buf;
 306         if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
 307                 err = EXT2_ET_BAD_EA_HEADER;
 308                 goto out2;
 309         }
 310
 311         header->h_refcount--;
 312         err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
 313         if (err)
 314                 goto out2;
 315
 316         /* Erase link to block */
 317         ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, 0);
 318         if (header->h_refcount == 0)
 319                 ext2fs_block_alloc_stats2(fs, blk, -1);
 320         err = ext2fs_iblk_sub_blocks(fs, (struct ext2_inode *)inode, 1);
 321         if (err)
 322                 goto out2;
 323
 324         /* Write inode? */
 325         if (inode == &i) {
 326                 err = ext2fs_write_inode_full(fs, ino, (struct ext2_inode *)&i,
 327                                               sizeof(struct ext2_inode_large));
 328                 if (err)
 329                         goto out2;
 330         }
 331
 332 out2:
 333         ext2fs_free_mem(&block_buf);
 334 out:
 335         return err;
 336 }
 337
 338 static errcode_t prep_ea_block_for_write(ext2_filsys fs, ext2_ino_t ino,
 339                                          struct ext2_inode_large *inode)
 340 {
 341         struct ext2_ext_attr_header *header;
 342         void *block_buf = NULL;
 343         dgrp_t grp;
 344         blk64_t blk, goal;
 345         errcode_t err;
 346
 347         /* Do we already have an EA block? */
 348         blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
 349         if (blk != 0) {
 350                 if ((blk < fs->super->s_first_data_block) ||
 351                     (blk >= ext2fs_blocks_count(fs->super))) {
 352                         err = EXT2_ET_BAD_EA_BLOCK_NUM;
 353                         goto out;
 354                 }
 355
 356                 err = ext2fs_get_mem(fs->blocksize, &block_buf);
 357                 if (err)
 358                         goto out;
 359
 360                 err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
 361                 if (err)
 362                         goto out2;
 363
 364                 header = (struct ext2_ext_attr_header *) block_buf;
 365                 if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
 366                         err = EXT2_ET_BAD_EA_HEADER;
 367                         goto out2;
 368                 }
 369
 370                 /* Single-user block.  We're done here. */
 371                 if (header->h_refcount == 1)
 372                         goto out2;
 373
 374                 /* We need to CoW the block. */
 375                 header->h_refcount--;
 376                 err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
 377                 if (err)
 378                         goto out2;
 379         } else {
 380                 /* No block, we must increment i_blocks */
 381                 err = ext2fs_iblk_add_blocks(fs, (struct ext2_inode *)inode,
 382                                              1);
 383                 if (err)
 384                         goto out;
 385         }
 386
 387         /* Allocate a block */
 388         grp = ext2fs_group_of_ino(fs, ino);
 389         goal = ext2fs_inode_table_loc(fs, grp);
 390         err = ext2fs_alloc_block2(fs, goal, NULL, &blk);
 391         if (err)
 392                 goto out2;
 393         ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, blk);
 394 out2:
 395         if (block_buf)
 396                 ext2fs_free_mem(&block_buf);
 397 out:
 398         return err;
 399 }
 400
 401
 402 static errcode_t write_xattrs_to_buffer(struct ext2_xattr_handle *handle,
 403                                         struct ext2_xattr **pos,
 404                                         void *entries_start,
 405                                         unsigned int storage_size,
 406                                         unsigned int value_offset_correction)
 407 {
 408         struct ext2_xattr *x = *pos;
 409         struct ext2_ext_attr_entry *e = entries_start;
 410         void *end = entries_start + storage_size;
 411         char *shortname;
 412         unsigned int entry_size, value_size;
 413         int idx, ret;
 414
 415         /* For all remaining x...  */
 416         for (; x < handle->attrs + handle->length; x++) {
 417                 if (!x->name)
 418                         continue;
 419
 420                 /* Calculate index and shortname position */
 421                 shortname = x->name;
 422                 ret = find_ea_index(x->name, &shortname, &idx);
 423
 424                 /* Calculate entry and value size */
 425                 entry_size = (sizeof(*e) + strlen(shortname) +
 426                               EXT2_EXT_ATTR_PAD - 1) &
 427                              ~(EXT2_EXT_ATTR_PAD - 1);
 428                 value_size = ((x->value_len + EXT2_EXT_ATTR_PAD - 1) /
 429                               EXT2_EXT_ATTR_PAD) * EXT2_EXT_ATTR_PAD;
 430
 431                 /*
 432                  * Would entry collide with value?
 433                  * Note that we must leave sufficient room for a (u32)0 to
 434                  * mark the end of the entries.
 435                  */
 436                 if ((void *)e + entry_size + sizeof(__u32) > end - value_size)
 437                         break;
 438
 439                 /* Fill out e appropriately */
 440                 e->e_name_len = strlen(shortname);
 441                 e->e_name_index = (ret ? idx : 0);
 442                 e->e_value_offs = end - value_size - (void *)entries_start +
 443                                 value_offset_correction;
 444                 e->e_value_block = 0;
 445                 e->e_value_size = x->value_len;
 446
 447                 /* Store name and value */
 448                 end -= value_size;
 449                 memcpy((void *)e + sizeof(*e), shortname, e->e_name_len);
 450                 memcpy(end, x->value, e->e_value_size);
 451
 452                 e->e_hash = ext2fs_ext_attr_hash_entry(e, end);
 453
 454                 e = EXT2_EXT_ATTR_NEXT(e);
 455                 *(__u32 *)e = 0;
 456         }
 457         *pos = x;
 458
 459         return 0;
 460 }
 461
 462 errcode_t ext2fs_xattrs_write(struct ext2_xattr_handle *handle)
 463 {
 464         struct ext2_xattr *x;
 465         struct ext2_inode_large *inode;
 466         void *start, *block_buf = NULL;
 467         struct ext2_ext_attr_header *header;
 468         __u32 ea_inode_magic;
 469         blk64_t blk;
 470         unsigned int storage_size;
 471         unsigned int i;
 472         errcode_t err;
 473
 474         i = EXT2_INODE_SIZE(handle->fs->super);
 475         if (i < sizeof(*inode))
 476                 i = sizeof(*inode);
 477         err = ext2fs_get_memzero(i, &inode);
 478         if (err)
 479                 return err;
 480
 481         err = ext2fs_read_inode_full(handle->fs, handle->ino,
 482                                      (struct ext2_inode *)inode,
 483                                      EXT2_INODE_SIZE(handle->fs->super));
 484         if (err)
 485                 goto out;
 486
 487         x = handle->attrs;
 488         /* Does the inode have size for EA? */
 489         if (EXT2_INODE_SIZE(handle->fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
 490                                                   inode->i_extra_isize +
 491                                                   sizeof(__u32))
 492                 goto write_ea_block;
 493
 494         /* Write the inode EA */
 495         ea_inode_magic = EXT2_EXT_ATTR_MAGIC;
 496         memcpy(((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 497                inode->i_extra_isize, &ea_inode_magic, sizeof(__u32));
 498         storage_size = EXT2_INODE_SIZE(handle->fs->super) -
 499                 EXT2_GOOD_OLD_INODE_SIZE - inode->i_extra_isize -
 500                 sizeof(__u32);
 501         start = ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 502                 inode->i_extra_isize + sizeof(__u32);
 503
 504         err = write_xattrs_to_buffer(handle, &x, start, storage_size, 0);
 505         if (err)
 506                 goto out;
 507
 508         /* Are we done? */
 509         if (x == handle->attrs + handle->length)
 510                 goto skip_ea_block;
 511
 512 write_ea_block:
 513         /* Write the EA block */
 514         err = ext2fs_get_memzero(handle->fs->blocksize, &block_buf);
 515         if (err)
 516                 goto out;
 517
 518         storage_size = handle->fs->blocksize -
 519                 sizeof(struct ext2_ext_attr_header);
 520         start = block_buf + sizeof(struct ext2_ext_attr_header);
 521
 522         err = write_xattrs_to_buffer(handle, &x, start, storage_size,
 523                                      (void *)start - block_buf);
 524         if (err)
 525                 goto out2;
 526
 527         if (x < handle->attrs + handle->length) {
 528                 err = EXT2_ET_EA_NO_SPACE;
 529                 goto out2;
 530         }
 531
 532         /* Write a header on the EA block */
 533         header = block_buf;
 534         header->h_magic = EXT2_EXT_ATTR_MAGIC;
 535         header->h_refcount = 1;
 536         header->h_blocks = 1;
 537
 538         /* Get a new block for writing */
 539         err = prep_ea_block_for_write(handle->fs, handle->ino, inode);
 540         if (err)
 541                 goto out2;
 542
 543         /* Finally, write the new EA block */
 544         blk = ext2fs_file_acl_block(handle->fs,
 545                                     (struct ext2_inode *)inode);
 546         err = ext2fs_write_ext_attr3(handle->fs, blk, block_buf,
 547                                      handle->ino);
 548         if (err)
 549                 goto out2;
 550
 551 skip_ea_block:
 552         blk = ext2fs_file_acl_block(handle->fs, (struct ext2_inode *)inode);
 553         if (!block_buf && blk) {
 554                 /* xattrs shrunk, free the block */
 555                 err = ext2fs_free_ext_attr(handle->fs, handle->ino, inode);
 556                 if (err)
 557                         goto out;
 558         }
 559
 560         /* Write the inode */
 561         err = ext2fs_write_inode_full(handle->fs, handle->ino,
 562                                       (struct ext2_inode *)inode,
 563                                       EXT2_INODE_SIZE(handle->fs->super));
 564         if (err)
 565                 goto out2;
 566
 567 out2:
 568         ext2fs_free_mem(&block_buf);
 569 out:
 570         ext2fs_free_mem(&inode);
 571         handle->dirty = 0;
 572         return err;
 573 }
 574
 575 static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
 576                                          struct ext2_ext_attr_entry *entries,
 577                                          unsigned int storage_size,
 578                                          void *value_start,
 579                                          size_t *nr_read)
 580 {
 581         struct ext2_xattr *x;
 582         struct ext2_ext_attr_entry *entry;
 583         const char *prefix;
 584         void *ptr;
 585         unsigned int remain, prefix_len;
 586         errcode_t err;
 587
 588         x = handle->attrs;
 589         while (x->name)
 590                 x++;
 591
 592         entry = entries;
 593         while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
 594                 __u32 hash;
 595
 596                 /* header eats this space */
 597                 remain -= sizeof(struct ext2_ext_attr_entry);
 598
 599                 /* is attribute name valid? */
 600                 if (EXT2_EXT_ATTR_SIZE(entry->e_name_len) > remain)
 601                         return EXT2_ET_EA_BAD_NAME_LEN;
 602
 603                 /* attribute len eats this space */
 604                 remain -= EXT2_EXT_ATTR_SIZE(entry->e_name_len);
 605
 606                 /* check value size */
 607                 if (entry->e_value_size > remain)
 608                         return EXT2_ET_EA_BAD_VALUE_SIZE;
 609
 610                 /* e_value_block must be 0 in inode's ea */
 611                 if (entry->e_value_block != 0)
 612                         return EXT2_ET_BAD_EA_BLOCK_NUM;
 613
 614                 hash = ext2fs_ext_attr_hash_entry(entry, value_start +
 615                                                          entry->e_value_offs);
 616
 617                 /* e_hash may be 0 in older inode's ea */
 618                 if (entry->e_hash != 0 && entry->e_hash != hash)
 619                         return EXT2_ET_BAD_EA_HASH;
 620
 621                 remain -= entry->e_value_size;
 622
 623                 /* Allocate space for more attrs? */
 624                 if (x == handle->attrs + handle->length) {
 625                         err = ext2fs_xattrs_expand(handle, 4);
 626                         if (err)
 627                                 return err;
 628                         x = handle->attrs + handle->length - 4;
 629                 }
 630
 631                 /* Extract name/value */
 632                 prefix = find_ea_prefix(entry->e_name_index);
 633                 prefix_len = (prefix ? strlen(prefix) : 0);
 634                 err = ext2fs_get_memzero(entry->e_name_len + prefix_len + 1,
 635                                          &x->name);
 636                 if (err)
 637                         return err;
 638                 if (prefix)
 639                         memcpy(x->name, prefix, prefix_len);
 640                 if (entry->e_name_len)
 641                         memcpy(x->name + prefix_len,
 642                                (void *)entry + sizeof(*entry),
 643                                entry->e_name_len);
 644
 645                 err = ext2fs_get_mem(entry->e_value_size, &x->value);
 646                 if (err)
 647                         return err;
 648                 x->value_len = entry->e_value_size;
 649                 memcpy(x->value, value_start + entry->e_value_offs,
 650                        entry->e_value_size);
 651                 x++;
 652                 (*nr_read)++;
 653                 entry = EXT2_EXT_ATTR_NEXT(entry);
 654         }
 655
 656         return 0;
 657 }
 658
 659 static void xattrs_free_keys(struct ext2_xattr_handle *h)
 660 {
 661         struct ext2_xattr *a = h->attrs;
 662         size_t i;
 663
 664         for (i = 0; i < h->length; i++) {
 665                 if (a[i].name)
 666                         ext2fs_free_mem(&a[i].name);
 667                 if (a[i].value)
 668                         ext2fs_free_mem(&a[i].value);
 669         }
 670         h->count = 0;
 671 }
 672
 673 errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle)
 674 {
 675         struct ext2_xattr *attrs = NULL, *x;
 676         struct ext2_inode_large *inode;
 677         struct ext2_ext_attr_header *header;
 678         __u32 ea_inode_magic;
 679         unsigned int storage_size;
 680         void *start, *block_buf = NULL;
 681         blk64_t blk;
 682         int i;
 683         errcode_t err;
 684
 685         i = EXT2_INODE_SIZE(handle->fs->super);
 686         if (i < sizeof(*inode))
 687                 i = sizeof(*inode);
 688         err = ext2fs_get_memzero(i, &inode);
 689         if (err)
 690                 return err;
 691
 692         err = ext2fs_read_inode_full(handle->fs, handle->ino,
 693                                      (struct ext2_inode *)inode,
 694                                      EXT2_INODE_SIZE(handle->fs->super));
 695         if (err)
 696                 goto out;
 697
 698         xattrs_free_keys(handle);
 699
 700         /* Does the inode have size for EA? */
 701         if (EXT2_INODE_SIZE(handle->fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
 702                                                   inode->i_extra_isize +
 703                                                   sizeof(__u32))
 704                 goto read_ea_block;
 705
 706         /* Look for EA in the inode */
 707         memcpy(&ea_inode_magic, ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 708                inode->i_extra_isize, sizeof(__u32));
 709         if (ea_inode_magic == EXT2_EXT_ATTR_MAGIC) {
 710                 storage_size = EXT2_INODE_SIZE(handle->fs->super) -
 711                         EXT2_GOOD_OLD_INODE_SIZE - inode->i_extra_isize -
 712                         sizeof(__u32);
 713                 start = ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 714                         inode->i_extra_isize + sizeof(__u32);
 715
 716                 err = read_xattrs_from_buffer(handle, start, storage_size,
 717                                               start, &handle->count);
 718                 if (err)
 719                         goto out;
 720         }
 721
 722 read_ea_block:
 723         /* Look for EA in a separate EA block */
 724         blk = ext2fs_file_acl_block(handle->fs, (struct ext2_inode *)inode);
 725         if (blk != 0) {
 726                 if ((blk < handle->fs->super->s_first_data_block) ||
 727                     (blk >= ext2fs_blocks_count(handle->fs->super))) {
 728                         err = EXT2_ET_BAD_EA_BLOCK_NUM;
 729                         goto out;
 730                 }
 731
 732                 err = ext2fs_get_mem(handle->fs->blocksize, &block_buf);
 733                 if (err)
 734                         goto out;
 735
 736                 err = ext2fs_read_ext_attr3(handle->fs, blk, block_buf,
 737                                             handle->ino);
 738                 if (err)
 739                         goto out3;
 740
 741                 header = (struct ext2_ext_attr_header *) block_buf;
 742                 if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
 743                         err = EXT2_ET_BAD_EA_HEADER;
 744                         goto out3;
 745                 }
 746
 747                 if (header->h_blocks != 1) {
 748                         err = EXT2_ET_BAD_EA_HEADER;
 749                         goto out3;
 750                 }
 751
 752                 /* Read EAs */
 753                 storage_size = handle->fs->blocksize -
 754                         sizeof(struct ext2_ext_attr_header);
 755                 start = block_buf + sizeof(struct ext2_ext_attr_header);
 756                 err = read_xattrs_from_buffer(handle, start, storage_size,
 757                                               block_buf, &handle->count);
 758                 if (err)
 759                         goto out3;
 760
 761                 ext2fs_free_mem(&block_buf);
 762         }
 763
 764         ext2fs_free_mem(&block_buf);
 765         ext2fs_free_mem(&inode);
 766         return 0;
 767
 768 out3:
 769         ext2fs_free_mem(&block_buf);
 770 out:
 771         ext2fs_free_mem(&inode);
 772         return err;
 773 }
 774
 775 errcode_t ext2fs_xattrs_iterate(struct ext2_xattr_handle *h,
 776                                 int (*func)(char *name, char *value,
 777                                             size_t value_len, void *data),
 778                                 void *data)
 779 {
 780         struct ext2_xattr *x;
 781         errcode_t err;
 782         int ret;
 783
 784         for (x = h->attrs; x < h->attrs + h->length; x++) {
 785                 if (!x->name)
 786                         continue;
 787
 788                 ret = func(x->name, x->value, x->value_len, data);
 789                 if (ret & XATTR_CHANGED)
 790                         h->dirty = 1;
 791                 if (ret & XATTR_ABORT)
 792                         return 0;
 793         }
 794
 795         return 0;
 796 }
 797
 798 errcode_t ext2fs_xattr_get(struct ext2_xattr_handle *h, const char *key,
 799                            void **value, size_t *value_len)
 800 {
 801         struct ext2_xattr *x;
 802         void *val;
 803         errcode_t err;
 804
 805         for (x = h->attrs; x < h->attrs + h->length; x++) {
 806                 if (!x->name)
 807                         continue;
 808
 809                 if (strcmp(x->name, key) == 0) {
 810                         err = ext2fs_get_mem(x->value_len, &val);
 811                         if (err)
 812                                 return err;
 813                         memcpy(val, x->value, x->value_len);
 814                         *value = val;
 815                         *value_len = x->value_len;
 816                         return 0;
 817                 }
 818         }
 819
 820         return EXT2_ET_EA_KEY_NOT_FOUND;
 821 }
 822
 823 errcode_t ext2fs_xattr_inode_max_size(ext2_filsys fs, ext2_ino_t ino,
 824                                       size_t *size)
 825 {
 826         struct ext2_ext_attr_header *header;
 827         struct ext2_ext_attr_entry *entry;
 828         struct ext2_inode_large *inode;
 829         __u32 ea_inode_magic;
 830         unsigned int storage_size, freesize, minoff;
 831         void *start;
 832         int i;
 833         errcode_t err;
 834
 835         i = EXT2_INODE_SIZE(fs->super);
 836         if (i < sizeof(*inode))
 837                 i = sizeof(*inode);
 838         err = ext2fs_get_memzero(i, &inode);
 839         if (err)
 840                 return err;
 841
 842         err = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)inode,
 843                                      EXT2_INODE_SIZE(fs->super));
 844         if (err)
 845                 goto out;
 846
 847         /* Does the inode have size for EA? */
 848         if (EXT2_INODE_SIZE(fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
 849                                                   inode->i_extra_isize +
 850                                                   sizeof(__u32)) {
 851                 err = EXT2_ET_INLINE_DATA_NO_SPACE;
 852                 goto out;
 853         }
 854
 855         minoff = EXT2_INODE_SIZE(fs->super) - sizeof(*inode) - sizeof(__u32);
 856         memcpy(&ea_inode_magic, ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 857                inode->i_extra_isize, sizeof(__u32));
 858         if (ea_inode_magic == EXT2_EXT_ATTR_MAGIC) {
 859                 /* has xattrs.  calculate the size */
 860                 storage_size = EXT2_INODE_SIZE(fs->super) -
 861                         EXT2_GOOD_OLD_INODE_SIZE - inode->i_extra_isize -
 862                         sizeof(__u32);
 863                 start= ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
 864                         inode->i_extra_isize + sizeof(__u32);
 865                 entry = start;
 866                 while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
 867                         if (!entry->e_value_block && entry->e_value_size) {
 868                                 unsigned int offs = entry->e_value_offs;
 869                                 if (offs < minoff)
 870                                         minoff = offs;
 871                         }
 872                         entry = EXT2_EXT_ATTR_NEXT(entry);
 873                 }
 874                 *size = minoff - ((char *)entry - (char *)start) - sizeof(__u32);
 875         } else {
 876                 /* no xattr.  return a maximum size */
 877                 *size = EXT2_EXT_ATTR_SIZE(minoff -
 878                                            EXT2_EXT_ATTR_LEN(strlen("data")) -
 879                                            EXT2_EXT_ATTR_ROUND - sizeof(__u32));
 880         }
 881
 882 out:
 883         ext2fs_free_mem(&inode);
 884         return err;
 885 }
 886
 887 errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *handle,
 888                            const char *key,
 889                            const void *value,
 890                            size_t value_len)
 891 {
 892         struct ext2_xattr *x, *last_empty;
 893         char *new_value;
 894         errcode_t err;
 895
 896         last_empty = NULL;
 897         for (x = handle->attrs; x < handle->attrs + handle->length; x++) {
 898                 if (!x->name) {
 899                         last_empty = x;
 900                         continue;
 901                 }
 902
 903                 /* Replace xattr */
 904                 if (strcmp(x->name, key) == 0) {
 905                         err = ext2fs_get_mem(value_len, &new_value);
 906                         if (err)
 907                                 return err;
 908                         memcpy(new_value, value, value_len);
 909                         ext2fs_free_mem(&x->value);
 910                         x->value = new_value;
 911                         x->value_len = value_len;
 912                         handle->dirty = 1;
 913                         return 0;
 914                 }
 915         }
 916
 917         /* Add attr to empty slot */
 918         if (last_empty) {
 919                 err = ext2fs_get_mem(strlen(key) + 1, &last_empty->name);
 920                 if (err)
 921                         return err;
 922                 strcpy(last_empty->name, key);
 923
 924                 err = ext2fs_get_mem(value_len, &last_empty->value);
 925                 if (err)
 926                         return err;
 927                 memcpy(last_empty->value, value, value_len);
 928                 last_empty->value_len = value_len;
 929                 handle->dirty = 1;
 930                 handle->count++;
 931                 return 0;
 932         }
 933
 934         /* Expand array, append slot */
 935         err = ext2fs_xattrs_expand(handle, 4);
 936         if (err)
 937                 return err;
 938
 939         x = handle->attrs + handle->length - 4;
 940         err = ext2fs_get_mem(strlen(key) + 1, &x->name);
 941         if (err)
 942                 return err;
 943         strcpy(x->name, key);
 944
 945         err = ext2fs_get_mem(value_len, &x->value);
 946         if (err)
 947                 return err;
 948         memcpy(x->value, value, value_len);
 949         x->value_len = value_len;
 950         handle->dirty = 1;
 951         handle->count++;
 952         return 0;
 953 }
 954
 955 errcode_t ext2fs_xattr_remove(struct ext2_xattr_handle *handle,
 956                               const char *key)
 957 {
 958         struct ext2_xattr *x;
 959         errcode_t err;
 960
 961         for (x = handle->attrs; x < handle->attrs + handle->length; x++) {
 962                 if (!x->name)
 963                         continue;
 964
 965                 if (strcmp(x->name, key) == 0) {
 966                         ext2fs_free_mem(&x->name);
 967                         ext2fs_free_mem(&x->value);
 968                         x->value_len = 0;
 969                         handle->dirty = 1;
 970                         handle->count--;
 971                         return 0;
 972                 }
 973         }
 974
 975         return EXT2_ET_EA_KEY_NOT_FOUND;
 976 }
 977
 978 errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
 979                              struct ext2_xattr_handle **handle)
 980 {
 981         struct ext2_xattr_handle *h;
 982         errcode_t err;
 983
 984         if (!EXT2_HAS_COMPAT_FEATURE(fs->super,
 985                                      EXT2_FEATURE_COMPAT_EXT_ATTR) &&
 986             !EXT2_HAS_INCOMPAT_FEATURE(fs->super,
 987                                      EXT4_FEATURE_INCOMPAT_INLINE_DATA))
 988                 return EXT2_ET_MISSING_EA_FEATURE;
 989
 990         err = ext2fs_get_memzero(sizeof(*h), &h);
 991         if (err)
 992                 return err;
 993
 994         h->length = 4;
 995         err = ext2fs_get_arrayzero(h->length, sizeof(struct ext2_xattr),
 996                                    &h->attrs);
 997         if (err) {
 998                 ext2fs_free_mem(&h);
 999                 return err;
1000         }
1001         h->count = 0;
1002         h->ino = ino;
1003         h->fs = fs;
1004         *handle = h;
1005         return 0;
1006 }
1007
1008 errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle)
1009 {
1010         struct ext2_xattr_handle *h = *handle;
1011         errcode_t err;
1012
1013         if (h->dirty) {
1014                 err = ext2fs_xattrs_write(h);
1015                 if (err)
1016                         return err;
1017         }
1018
1019         xattrs_free_keys(h);
1020         ext2fs_free_mem(&h->attrs);
1021         ext2fs_free_mem(handle);
1022         return 0;
1023 }
1024
1025 size_t ext2fs_xattrs_count(struct ext2_xattr_handle *handle)
1026 {
1027         return handle->count;
1028 }