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ext_attr.c
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/*
* ext_attr.c --- extended attribute blocks
*
* Copyright (C) 2001 Andreas Gruenbacher, <[email protected]>
*
* Copyright (C) 2002 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include "config.h"
#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <time.h>
#include "ext2_fs.h"
#include "ext2_ext_attr.h"
#include "ext4_acl.h"
#include "ext2fs.h"
static errcode_t read_ea_inode_hash(ext2_filsys fs, ext2_ino_t ino, __u32 *hash)
{
struct ext2_inode inode;
errcode_t retval;
retval = ext2fs_read_inode(fs, ino, &inode);
if (retval)
return retval;
*hash = ext2fs_get_ea_inode_hash(&inode);
return 0;
}
#define NAME_HASH_SHIFT 5
#define VALUE_HASH_SHIFT 16
/*
* ext2_xattr_hash_entry()
*
* Compute the hash of an extended attribute.
*/
__u32 ext2fs_ext_attr_hash_entry(struct ext2_ext_attr_entry *entry, void *data)
{
__u32 hash = 0;
char *name = ((char *) entry) + sizeof(struct ext2_ext_attr_entry);
int n;
for (n = 0; n < entry->e_name_len; n++) {
hash = (hash << NAME_HASH_SHIFT) ^
(hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
*name++;
}
/* The hash needs to be calculated on the data in little-endian. */
if (entry->e_value_inum == 0 && entry->e_value_size != 0) {
__u32 *value = (__u32 *)data;
for (n = (entry->e_value_size + EXT2_EXT_ATTR_ROUND) >>
EXT2_EXT_ATTR_PAD_BITS; n; n--) {
hash = (hash << VALUE_HASH_SHIFT) ^
(hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
ext2fs_le32_to_cpu(*value++);
}
}
return hash;
}
/*
* ext2fs_ext_attr_hash_entry2()
*
* Compute the hash of an extended attribute.
* This version of the function supports hashing entries that reference
* external inodes (ea_inode feature).
*/
errcode_t ext2fs_ext_attr_hash_entry2(ext2_filsys fs,
struct ext2_ext_attr_entry *entry,
void *data, __u32 *hash)
{
*hash = ext2fs_ext_attr_hash_entry(entry, data);
if (entry->e_value_inum) {
__u32 ea_inode_hash;
errcode_t retval;
retval = read_ea_inode_hash(fs, entry->e_value_inum,
&ea_inode_hash);
if (retval)
return retval;
*hash = (*hash << VALUE_HASH_SHIFT) ^
(*hash >> (8*sizeof(*hash) - VALUE_HASH_SHIFT)) ^
ea_inode_hash;
}
return 0;
}
#undef NAME_HASH_SHIFT
#undef VALUE_HASH_SHIFT
#define BLOCK_HASH_SHIFT 16
/* Mirrors ext4_xattr_rehash() implementation in kernel. */
void ext2fs_ext_attr_block_rehash(struct ext2_ext_attr_header *header,
struct ext2_ext_attr_entry *end)
{
struct ext2_ext_attr_entry *here;
__u32 hash = 0;
here = (struct ext2_ext_attr_entry *)(header+1);
while (here < end && !EXT2_EXT_IS_LAST_ENTRY(here)) {
if (!here->e_hash) {
/* Block is not shared if an entry's hash value == 0 */
hash = 0;
break;
}
hash = (hash << BLOCK_HASH_SHIFT) ^
(hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
here->e_hash;
here = EXT2_EXT_ATTR_NEXT(here);
}
header->h_hash = hash;
}
#undef BLOCK_HASH_SHIFT
__u32 ext2fs_get_ea_inode_hash(struct ext2_inode *inode)
{
return inode->i_atime;
}
void ext2fs_set_ea_inode_hash(struct ext2_inode *inode, __u32 hash)
{
inode->i_atime = hash;
}
__u64 ext2fs_get_ea_inode_ref(struct ext2_inode *inode)
{
return ((__u64)inode->i_ctime << 32) | inode->osd1.linux1.l_i_version;
}
void ext2fs_set_ea_inode_ref(struct ext2_inode *inode, __u64 ref_count)
{
inode->i_ctime = (__u32)(ref_count >> 32);
inode->osd1.linux1.l_i_version = (__u32)ref_count;
}
static errcode_t check_ext_attr_header(struct ext2_ext_attr_header *header)
{
if ((header->h_magic != EXT2_EXT_ATTR_MAGIC_v1 &&
header->h_magic != EXT2_EXT_ATTR_MAGIC) ||
header->h_blocks != 1)
return EXT2_ET_BAD_EA_HEADER;
return 0;
}
errcode_t ext2fs_read_ext_attr3(ext2_filsys fs, blk64_t block, void *buf,
ext2_ino_t inum)
{
int csum_failed = 0;
errcode_t retval;
retval = io_channel_read_blk64(fs->io, block, 1, buf);
if (retval)
return retval;
if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
!ext2fs_ext_attr_block_csum_verify(fs, inum, block, buf))
csum_failed = 1;
#ifdef WORDS_BIGENDIAN
ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
#endif
retval = check_ext_attr_header(buf);
if (retval == 0 && csum_failed)
retval = EXT2_ET_EXT_ATTR_CSUM_INVALID;
return retval;
}
errcode_t ext2fs_read_ext_attr2(ext2_filsys fs, blk64_t block, void *buf)
{
return ext2fs_read_ext_attr3(fs, block, buf, 0);
}
errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
{
return ext2fs_read_ext_attr2(fs, block, buf);
}
errcode_t ext2fs_write_ext_attr3(ext2_filsys fs, blk64_t block, void *inbuf,
ext2_ino_t inum)
{
errcode_t retval;
char *write_buf;
#ifdef WORDS_BIGENDIAN
retval = ext2fs_get_mem(fs->blocksize, &write_buf);
if (retval)
return retval;
ext2fs_swap_ext_attr(write_buf, inbuf, fs->blocksize, 1);
#else
write_buf = (char *) inbuf;
#endif
retval = ext2fs_ext_attr_block_csum_set(fs, inum, block,
(struct ext2_ext_attr_header *)write_buf);
if (retval)
return retval;
retval = io_channel_write_blk64(fs->io, block, 1, write_buf);
#ifdef WORDS_BIGENDIAN
ext2fs_free_mem(&write_buf);
#endif
if (!retval)
ext2fs_mark_changed(fs);
return retval;
}
errcode_t ext2fs_write_ext_attr2(ext2_filsys fs, blk64_t block, void *inbuf)
{
return ext2fs_write_ext_attr3(fs, block, inbuf, 0);
}
errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
{
return ext2fs_write_ext_attr2(fs, block, inbuf);
}
/*
* This function adjusts the reference count of the EA block.
*/
errcode_t ext2fs_adjust_ea_refcount3(ext2_filsys fs, blk64_t blk,
char *block_buf, int adjust,
__u32 *newcount, ext2_ino_t inum)
{
errcode_t retval;
struct ext2_ext_attr_header *header;
char *buf = 0;
if ((blk >= ext2fs_blocks_count(fs->super)) ||
(blk < fs->super->s_first_data_block))
return EXT2_ET_BAD_EA_BLOCK_NUM;
if (!block_buf) {
retval = ext2fs_get_mem(fs->blocksize, &buf);
if (retval)
return retval;
block_buf = buf;
}
retval = ext2fs_read_ext_attr3(fs, blk, block_buf, inum);
if (retval)
goto errout;
header = (struct ext2_ext_attr_header *) block_buf;
header->h_refcount += adjust;
if (newcount)
*newcount = header->h_refcount;
retval = ext2fs_write_ext_attr3(fs, blk, block_buf, inum);
if (retval)
goto errout;
errout:
if (buf)
ext2fs_free_mem(&buf);
return retval;
}
errcode_t ext2fs_adjust_ea_refcount2(ext2_filsys fs, blk64_t blk,
char *block_buf, int adjust,
__u32 *newcount)
{
return ext2fs_adjust_ea_refcount3(fs, blk, block_buf, adjust,
newcount, 0);
}
errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
char *block_buf, int adjust,
__u32 *newcount)
{
return ext2fs_adjust_ea_refcount2(fs, blk, block_buf, adjust,
newcount);
}
/* Manipulate the contents of extended attribute regions */
struct ext2_xattr {
char *name;
void *value;
unsigned int value_len;
ext2_ino_t ea_ino;
};
struct ext2_xattr_handle {
errcode_t magic;
ext2_filsys fs;
struct ext2_xattr *attrs;
int capacity;
int count;
int ibody_count;
ext2_ino_t ino;
unsigned int flags;
};
static errcode_t ext2fs_xattrs_expand(struct ext2_xattr_handle *h,
unsigned int expandby)
{
struct ext2_xattr *new_attrs;
errcode_t err;
err = ext2fs_get_arrayzero(h->capacity + expandby,
sizeof(struct ext2_xattr), &new_attrs);
if (err)
return err;
memcpy(new_attrs, h->attrs, h->capacity * sizeof(struct ext2_xattr));
ext2fs_free_mem(&h->attrs);
h->capacity += expandby;
h->attrs = new_attrs;
return 0;
}
struct ea_name_index {
int index;
const char *name;
};
/* Keep these names sorted in order of decreasing specificity. */
static struct ea_name_index ea_names[] = {
{3, "system.posix_acl_default"},
{2, "system.posix_acl_access"},
{8, "system.richacl"},
{6, "security."},
{4, "trusted."},
{7, "system."},
{1, "user."},
{0, NULL},
};
static const char *find_ea_prefix(int index)
{
struct ea_name_index *e;
for (e = ea_names; e->name; e++)
if (e->index == index)
return e->name;
return NULL;
}
static int find_ea_index(const char *fullname, const char **name, int *index)
{
struct ea_name_index *e;
for (e = ea_names; e->name; e++) {
if (strncmp(fullname, e->name, strlen(e->name)) == 0) {
*name = fullname + strlen(e->name);
*index = e->index;
return 1;
}
}
return 0;
}
errcode_t ext2fs_free_ext_attr(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode_large *inode)
{
struct ext2_ext_attr_header *header;
void *block_buf = NULL;
blk64_t blk;
errcode_t err;
struct ext2_inode_large i;
/* Read inode? */
if (inode == NULL) {
err = ext2fs_read_inode_full(fs, ino, (struct ext2_inode *)&i,
sizeof(struct ext2_inode_large));
if (err)
return err;
inode = &i;
}
/* Do we already have an EA block? */
blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
if (blk == 0)
return 0;
/* Find block, zero it, write back */
if ((blk < fs->super->s_first_data_block) ||
(blk >= ext2fs_blocks_count(fs->super))) {
err = EXT2_ET_BAD_EA_BLOCK_NUM;
goto out;
}
err = ext2fs_get_mem(fs->blocksize, &block_buf);
if (err)
goto out;
err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
if (err)
goto out2;
/* We only know how to deal with v2 EA blocks */
header = (struct ext2_ext_attr_header *) block_buf;
if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
err = EXT2_ET_BAD_EA_HEADER;
goto out2;
}
header->h_refcount--;
err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
if (err)
goto out2;
/* Erase link to block */
ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, 0);
if (header->h_refcount == 0)
ext2fs_block_alloc_stats2(fs, blk, -1);
err = ext2fs_iblk_sub_blocks(fs, (struct ext2_inode *)inode, 1);
if (err)
goto out2;
/* Write inode? */
if (inode == &i) {
err = ext2fs_write_inode_full(fs, ino, (struct ext2_inode *)&i,
sizeof(struct ext2_inode_large));
if (err)
goto out2;
}
out2:
ext2fs_free_mem(&block_buf);
out:
return err;
}
static errcode_t prep_ea_block_for_write(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode_large *inode)
{
struct ext2_ext_attr_header *header;
void *block_buf = NULL;
blk64_t blk, goal;
errcode_t err;
/* Do we already have an EA block? */
blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
if (blk != 0) {
if ((blk < fs->super->s_first_data_block) ||
(blk >= ext2fs_blocks_count(fs->super))) {
err = EXT2_ET_BAD_EA_BLOCK_NUM;
goto out;
}
err = ext2fs_get_mem(fs->blocksize, &block_buf);
if (err)
goto out;
err = ext2fs_read_ext_attr3(fs, blk, block_buf, ino);
if (err)
goto out2;
/* We only know how to deal with v2 EA blocks */
header = (struct ext2_ext_attr_header *) block_buf;
if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
err = EXT2_ET_BAD_EA_HEADER;
goto out2;
}
/* Single-user block. We're done here. */
if (header->h_refcount == 1)
goto out2;
/* We need to CoW the block. */
header->h_refcount--;
err = ext2fs_write_ext_attr3(fs, blk, block_buf, ino);
if (err)
goto out2;
} else {
/* No block, we must increment i_blocks */
err = ext2fs_iblk_add_blocks(fs, (struct ext2_inode *)inode,
1);
if (err)
goto out;
}
/* Allocate a block */
goal = ext2fs_find_inode_goal(fs, ino, (struct ext2_inode *)inode, 0);
err = ext2fs_alloc_block2(fs, goal, NULL, &blk);
if (err)
goto out2;
ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, blk);
out2:
if (block_buf)
ext2fs_free_mem(&block_buf);
out:
return err;
}
static inline int
posix_acl_xattr_count(size_t size)
{
if (size < sizeof(posix_acl_xattr_header))
return -1;
size -= sizeof(posix_acl_xattr_header);
if (size % sizeof(posix_acl_xattr_entry))
return -1;
return size / sizeof(posix_acl_xattr_entry);
}
/*
* The lgetxattr function returns data formatted in the POSIX extended
* attribute format. The on-disk format uses a more compact encoding.
* See the ext4_acl_to_disk in fs/ext4/acl.c.
*/
static errcode_t convert_posix_acl_to_disk_buffer(const void *value, size_t size,
void *out_buf, size_t *size_out)
{
const posix_acl_xattr_header *header =
(const posix_acl_xattr_header*) value;
const posix_acl_xattr_entry *end, *entry =
(const posix_acl_xattr_entry *)(header+1);
ext4_acl_header *ext_acl;
size_t s;
char *e;
int count;
if (!value)
return EINVAL;
if (size < sizeof(posix_acl_xattr_header))
return ENOMEM;
if (header->a_version != ext2fs_cpu_to_le32(POSIX_ACL_XATTR_VERSION))
return EINVAL;
count = posix_acl_xattr_count(size);
ext_acl = out_buf;
ext_acl->a_version = ext2fs_cpu_to_le32(EXT4_ACL_VERSION);
if (count <= 0)
return EINVAL;
e = (char *) out_buf + sizeof(ext4_acl_header);
s = sizeof(ext4_acl_header);
for (end = entry + count; entry != end;entry++) {
ext4_acl_entry *disk_entry = (ext4_acl_entry*) e;
disk_entry->e_tag = ext2fs_cpu_to_le16(entry->e_tag);
disk_entry->e_perm = ext2fs_cpu_to_le16(entry->e_perm);
switch(entry->e_tag) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
e += sizeof(ext4_acl_entry_short);
s += sizeof(ext4_acl_entry_short);
break;
case ACL_USER:
case ACL_GROUP:
disk_entry->e_id = ext2fs_cpu_to_le32(entry->e_id);
e += sizeof(ext4_acl_entry);
s += sizeof(ext4_acl_entry);
break;
}
}
*size_out = s;
return 0;
}
static errcode_t convert_disk_buffer_to_posix_acl(const void *value, size_t size,
void **out_buf, size_t *size_out)
{
posix_acl_xattr_header *header;
posix_acl_xattr_entry *entry;
const ext4_acl_header *ext_acl = (const ext4_acl_header *) value;
errcode_t err;
const char *cp;
char *out;
if ((!value) ||
(size < sizeof(ext4_acl_header)) ||
(ext_acl->a_version != ext2fs_cpu_to_le32(EXT4_ACL_VERSION)))
return EINVAL;
err = ext2fs_get_mem(size * 2, &out);
if (err)
return err;
header = (posix_acl_xattr_header *) out;
header->a_version = ext2fs_cpu_to_le32(POSIX_ACL_XATTR_VERSION);
entry = (posix_acl_xattr_entry *) (out + sizeof(posix_acl_xattr_header));
cp = (const char *) value + sizeof(ext4_acl_header);
size -= sizeof(ext4_acl_header);
while (size > 0) {
const ext4_acl_entry *disk_entry = (const ext4_acl_entry *) cp;
entry->e_tag = ext2fs_le16_to_cpu(disk_entry->e_tag);
entry->e_perm = ext2fs_le16_to_cpu(disk_entry->e_perm);
switch(entry->e_tag) {
case ACL_USER_OBJ:
case ACL_GROUP_OBJ:
case ACL_MASK:
case ACL_OTHER:
entry->e_id = 0;
cp += sizeof(ext4_acl_entry_short);
size -= sizeof(ext4_acl_entry_short);
break;
case ACL_USER:
case ACL_GROUP:
entry->e_id = ext2fs_le32_to_cpu(disk_entry->e_id);
cp += sizeof(ext4_acl_entry);
size -= sizeof(ext4_acl_entry);
break;
default:
ext2fs_free_mem(&out);
return EINVAL;
break;
}
entry++;
}
*out_buf = out;
*size_out = ((char *) entry - out);
return 0;
}
static errcode_t
write_xattrs_to_buffer(ext2_filsys fs, struct ext2_xattr *attrs, int count,
void *entries_start, unsigned int storage_size,
unsigned int value_offset_correction, int write_hash)
{
struct ext2_xattr *x;
struct ext2_ext_attr_entry *e = entries_start;
char *end = (char *) entries_start + storage_size;
const char *shortname;
unsigned int value_size;
int idx, ret;
errcode_t err;
memset(entries_start, 0, storage_size);
for (x = attrs; x < attrs + count; x++) {
/* Calculate index and shortname position */
shortname = x->name;
ret = find_ea_index(x->name, &shortname, &idx);
value_size = ((x->value_len + EXT2_EXT_ATTR_PAD - 1) /
EXT2_EXT_ATTR_PAD) * EXT2_EXT_ATTR_PAD;
/* Fill out e appropriately */
e->e_name_len = strlen(shortname);
e->e_name_index = (ret ? idx : 0);
e->e_value_size = x->value_len;
e->e_value_inum = x->ea_ino;
/* Store name */
memcpy((char *)e + sizeof(*e), shortname, e->e_name_len);
if (x->ea_ino) {
e->e_value_offs = 0;
} else {
end -= value_size;
e->e_value_offs = end - (char *) entries_start +
value_offset_correction;
memcpy(end, x->value, e->e_value_size);
}
if (write_hash || x->ea_ino) {
err = ext2fs_ext_attr_hash_entry2(fs, e,
x->ea_ino ? 0 : end,
&e->e_hash);
if (err)
return err;
} else
e->e_hash = 0;
e = EXT2_EXT_ATTR_NEXT(e);
*(__u32 *)e = 0;
}
return 0;
}
errcode_t ext2fs_xattrs_write(struct ext2_xattr_handle *handle)
{
ext2_filsys fs = handle->fs;
const unsigned int inode_size = EXT2_INODE_SIZE(fs->super);
struct ext2_inode_large *inode;
char *start, *block_buf = NULL;
struct ext2_ext_attr_header *header;
__u32 ea_inode_magic;
blk64_t blk;
unsigned int storage_size;
unsigned int i;
errcode_t err;
EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EA_HANDLE);
i = inode_size;
if (i < sizeof(*inode))
i = sizeof(*inode);
err = ext2fs_get_memzero(i, &inode);
if (err)
return err;
err = ext2fs_read_inode_full(fs, handle->ino, EXT2_INODE(inode),
inode_size);
if (err)
goto out;
/* If extra_isize isn't set, we need to set it now */
if (inode->i_extra_isize == 0 &&
inode_size > EXT2_GOOD_OLD_INODE_SIZE) {
char *p = (char *)inode;
size_t extra = fs->super->s_want_extra_isize;
if (extra == 0)
extra = sizeof(__u32);
memset(p + EXT2_GOOD_OLD_INODE_SIZE, 0, extra);
inode->i_extra_isize = extra;
}
if (inode->i_extra_isize & 3) {
err = EXT2_ET_INODE_CORRUPTED;
goto out;
}
/* Does the inode have space for EA? */
if (inode->i_extra_isize < sizeof(inode->i_extra_isize) ||
inode_size <= EXT2_GOOD_OLD_INODE_SIZE + inode->i_extra_isize +
sizeof(__u32))
goto write_ea_block;
/* Write the inode EA */
ea_inode_magic = EXT2_EXT_ATTR_MAGIC;
memcpy(((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
inode->i_extra_isize, &ea_inode_magic, sizeof(__u32));
storage_size = inode_size - EXT2_GOOD_OLD_INODE_SIZE -
inode->i_extra_isize - sizeof(__u32);
start = ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
inode->i_extra_isize + sizeof(__u32);
err = write_xattrs_to_buffer(fs, handle->attrs, handle->ibody_count,
start, storage_size, 0, 0);
if (err)
goto out;
write_ea_block:
/* Are we done? */
if (handle->ibody_count == handle->count &&
!ext2fs_file_acl_block(fs, EXT2_INODE(inode)))
goto skip_ea_block;
/* Write the EA block */
err = ext2fs_get_memzero(fs->blocksize, &block_buf);
if (err)
goto out;
storage_size = fs->blocksize - sizeof(struct ext2_ext_attr_header);
start = block_buf + sizeof(struct ext2_ext_attr_header);
err = write_xattrs_to_buffer(fs, handle->attrs + handle->ibody_count,
handle->count - handle->ibody_count, start,
storage_size, start - block_buf, 1);
if (err)
goto out2;
/* Write a header on the EA block */
header = (struct ext2_ext_attr_header *) block_buf;
header->h_magic = EXT2_EXT_ATTR_MAGIC;
header->h_refcount = 1;
header->h_blocks = 1;
/* Get a new block for writing */
err = prep_ea_block_for_write(fs, handle->ino, inode);
if (err)
goto out2;
/* Finally, write the new EA block */
blk = ext2fs_file_acl_block(fs, EXT2_INODE(inode));
err = ext2fs_write_ext_attr3(fs, blk, block_buf, handle->ino);
if (err)
goto out2;
skip_ea_block:
blk = ext2fs_file_acl_block(fs, (struct ext2_inode *)inode);
if (!block_buf && blk) {
/* xattrs shrunk, free the block */
err = ext2fs_free_ext_attr(fs, handle->ino, inode);
if (err)
goto out;
}
/* Write the inode */
err = ext2fs_write_inode_full(fs, handle->ino, EXT2_INODE(inode),
inode_size);
if (err)
goto out2;
out2:
ext2fs_free_mem(&block_buf);
out:
ext2fs_free_mem(&inode);
return err;
}
static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
struct ext2_inode_large *inode,
struct ext2_ext_attr_entry *entries,
unsigned int storage_size,
char *value_start)
{
struct ext2_xattr *x;
struct ext2_ext_attr_entry *entry, *end;
const char *prefix;
unsigned int remain, prefix_len;
errcode_t err;
unsigned int values_size = storage_size +
((char *)entries - value_start);
/* find the end */
end = entries;
remain = storage_size;
while (remain >= sizeof(struct ext2_ext_attr_entry) &&
!EXT2_EXT_IS_LAST_ENTRY(end)) {
/* header eats this space */
remain -= sizeof(struct ext2_ext_attr_entry);
/* is attribute name valid? */
if (EXT2_EXT_ATTR_SIZE(end->e_name_len) > remain)
return EXT2_ET_EA_BAD_NAME_LEN;
/* attribute len eats this space */
remain -= EXT2_EXT_ATTR_SIZE(end->e_name_len);
end = EXT2_EXT_ATTR_NEXT(end);
}
entry = entries;
remain = storage_size;
while (remain >= sizeof(struct ext2_ext_attr_entry) &&
!EXT2_EXT_IS_LAST_ENTRY(entry)) {
/* Allocate space for more attrs? */
if (handle->count == handle->capacity) {
err = ext2fs_xattrs_expand(handle, 4);
if (err)
return err;
}
x = handle->attrs + handle->count;
/* header eats this space */
remain -= sizeof(struct ext2_ext_attr_entry);
/* attribute len eats this space */
remain -= EXT2_EXT_ATTR_SIZE(entry->e_name_len);
/* Extract name */
prefix = find_ea_prefix(entry->e_name_index);
prefix_len = (prefix ? strlen(prefix) : 0);
err = ext2fs_get_memzero(entry->e_name_len + prefix_len + 1,
&x->name);
if (err)
return err;
if (prefix)
memcpy(x->name, prefix, prefix_len);
if (entry->e_name_len)
memcpy(x->name + prefix_len,
(char *)entry + sizeof(*entry),
entry->e_name_len);
/* Check & copy value */
if (!ext2fs_has_feature_ea_inode(handle->fs->super) &&
entry->e_value_inum != 0)
return EXT2_ET_BAD_EA_BLOCK_NUM;
if (entry->e_value_inum == 0) {
if (entry->e_value_size > remain)
return EXT2_ET_EA_BAD_VALUE_SIZE;
if (entry->e_value_offs + entry->e_value_size > values_size)
return EXT2_ET_EA_BAD_VALUE_OFFSET;
if (entry->e_value_size > 0 &&
value_start + entry->e_value_offs <
(char *)end + sizeof(__u32))
return EXT2_ET_EA_BAD_VALUE_OFFSET;
remain -= entry->e_value_size;
err = ext2fs_get_mem(entry->e_value_size, &x->value);
if (err)
return err;
memcpy(x->value, value_start + entry->e_value_offs,
entry->e_value_size);
} else {
struct ext2_inode *ea_inode;
ext2_file_t ea_file;
if (entry->e_value_offs != 0)
return EXT2_ET_EA_BAD_VALUE_OFFSET;
if (entry->e_value_size > (64 * 1024))
return EXT2_ET_EA_BAD_VALUE_SIZE;
err = ext2fs_get_mem(entry->e_value_size, &x->value);
if (err)
return err;
err = ext2fs_file_open(handle->fs, entry->e_value_inum,
0, &ea_file);
if (err)
return err;
ea_inode = ext2fs_file_get_inode(ea_file);
if ((ea_inode->i_flags & EXT4_INLINE_DATA_FL) ||
!(ea_inode->i_flags & EXT4_EA_INODE_FL) ||
ea_inode->i_links_count == 0)
err = EXT2_ET_EA_INODE_CORRUPTED;
else if (ext2fs_file_get_size(ea_file) !=
entry->e_value_size)
err = EXT2_ET_EA_BAD_VALUE_SIZE;
else
err = ext2fs_file_read(ea_file, x->value,
entry->e_value_size, 0);
ext2fs_file_close(ea_file);
if (err)
return err;
}
x->ea_ino = entry->e_value_inum;
x->value_len = entry->e_value_size;
/* e_hash may be 0 in older inode's ea */
if (entry->e_hash != 0) {
__u32 hash;
void *data = (entry->e_value_inum != 0) ?
0 : value_start + entry->e_value_offs;
err = ext2fs_ext_attr_hash_entry2(handle->fs, entry,
data, &hash);
if (err)
return err;
if (entry->e_hash != hash) {
struct ext2_inode child;
/* Check whether this is an old Lustre-style
* ea_inode reference.
*/
err = ext2fs_read_inode(handle->fs,
entry->e_value_inum,
&child);
if (err)
return err;
if (child.i_mtime != handle->ino ||
child.i_generation != inode->i_generation)
return EXT2_ET_BAD_EA_HASH;
}
}
handle->count++;
entry = EXT2_EXT_ATTR_NEXT(entry);
}
return 0;
}
static void xattrs_free_keys(struct ext2_xattr_handle *h)
{
struct ext2_xattr *a = h->attrs;
int i;
for (i = 0; i < h->capacity; i++) {
if (a[i].name)
ext2fs_free_mem(&a[i].name);
if (a[i].value)
ext2fs_free_mem(&a[i].value);
}
h->count = 0;
h->ibody_count = 0;
}
errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle)
{
struct ext2_inode_large *inode;
struct ext2_ext_attr_header *header;
__u32 ea_inode_magic;
unsigned int storage_size;
char *start, *block_buf = NULL;
blk64_t blk;
size_t i;
errcode_t err;