Add functions to allow clients to get, set, and remove extended
attributes from any file. It also supports modifying EAs living in
i_file_acl.
v2: Put the header declarations in the correct part of ext2fs.h,
provide a function to release an EA block from an inode, and check
i_extra_isize to make sure we actually have space for in-inode EAs.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
lib/ext2fs/ext2_err.et.in | 18 +
lib/ext2fs/ext2fs.h | 28 ++
lib/ext2fs/ext_attr.c | 761 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 807 insertions(+)
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index 9cc1bd1..b819a90 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -482,4 +482,22 @@ ec EXT2_ET_BLOCK_BITMAP_CSUM_INVALID,
ec EXT2_ET_INLINE_DATA_CANT_ITERATE,
"Cannot block iterate on an inode containing inline data"
+ec EXT2_ET_EA_BAD_NAME_LEN,
+ "Extended attribute has an invalid name length"
+
+ec EXT2_ET_EA_BAD_VALUE_SIZE,
+ "Extended attribute has an invalid value length"
+
+ec EXT2_ET_BAD_EA_HASH,
+ "Extended attribute has an incorrect hash"
+
+ec EXT2_ET_BAD_EA_HEADER,
+ "Extended attribute block has a bad header"
+
+ec EXT2_ET_EA_KEY_NOT_FOUND,
+ "Extended attribute key not found"
+
+ec EXT2_ET_EA_NO_SPACE,
+ "Insufficient space to store extended attribute data"
+
end
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 5247922..93adae8 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -637,6 +637,13 @@ typedef struct stat ext2fs_struct_stat;
#define EXT2_FLAG_FLUSH_NO_SYNC 1
/*
+ * Modify and iterate extended attributes
+ */
+struct ext2_xattr_handle;
+#define XATTR_ABORT 1
+#define XATTR_CHANGED 2
+
+/*
* function prototypes
*/
static inline int ext2fs_has_group_desc_csum(ext2_filsys fs)
@@ -1151,6 +1158,27 @@ extern 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 ext2fs_xattrs_expand(struct ext2_xattr_handle *h,
+ unsigned int expandby);
+errcode_t ext2fs_xattrs_write(struct ext2_xattr_handle *handle);
+errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle);
+errcode_t ext2fs_xattrs_iterate(struct ext2_xattr_handle *h,
+ int (*func)(char *name, char *value,
+ void *data),
+ void *data);
+errcode_t ext2fs_xattr_get(struct ext2_xattr_handle *h, const char *key,
+ void **value, unsigned int *value_len);
+errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *handle,
+ const char *key,
+ const void *value,
+ unsigned int value_len);
+errcode_t ext2fs_xattr_remove(struct ext2_xattr_handle *handle,
+ const char *key);
+errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
+ struct ext2_xattr_handle **handle);
+errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle);
+errcode_t ext2fs_free_ext_attr(ext2_filsys fs, ext2_ino_t ino,
+ struct ext2_inode_large *inode);
/* extent.c */
extern errcode_t ext2fs_extent_header_verify(void *ptr, int size);
diff --git a/lib/ext2fs/ext_attr.c b/lib/ext2fs/ext_attr.c
index 9649a14..2a1e5e7 100644
--- a/lib/ext2fs/ext_attr.c
+++ b/lib/ext2fs/ext_attr.c
@@ -186,3 +186,764 @@ errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
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;
+};
+
+struct ext2_xattr_handle {
+ ext2_filsys fs;
+ struct ext2_xattr *attrs;
+ unsigned int length;
+ ext2_ino_t ino;
+ int dirty;
+};
+
+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->length + expandby,
+ sizeof(struct ext2_xattr), &new_attrs);
+ if (err)
+ return err;
+
+ memcpy(new_attrs, h->attrs, h->length * sizeof(struct ext2_xattr));
+ ext2fs_free_mem(&h->attrs);
+ h->length += expandby;
+ h->attrs = new_attrs;
+
+ return 0;
+}
+
+struct ea_name_index {
+ int index;
+ const char *name;
+};
+
+static struct ea_name_index ea_names[] = {
+ {1, "user."},
+ {2, "system.posix_acl_access"},
+ {3, "system.posix_acl_default"},
+ {4, "trusted."},
+ {6, "security."},
+ {7, "system."},
+ {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, char **name, int *index)
+{
+ struct ea_name_index *e;
+
+ for (e = ea_names; e->name; e++)
+ if (memcmp(fullname, e->name, strlen(e->name)) == 0) {
+ *name = (char *)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;
+ dgrp_t grp;
+ blk64_t blk, goal;
+ 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;
+
+ 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);
+
+ /* 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;
+ dgrp_t grp;
+ 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;
+
+ 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)
+ return 0;
+
+ /* 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 */
+ grp = ext2fs_group_of_ino(fs, ino);
+ goal = ext2fs_inode_table_loc(fs, grp);
+ err = ext2fs_alloc_block2(fs, goal, NULL, &blk);
+ if (err)
+ return err;
+ ext2fs_file_acl_block_set(fs, (struct ext2_inode *)inode, blk);
+out2:
+ ext2fs_free_mem(&block_buf);
+out:
+ return err;
+}
+
+
+static errcode_t write_xattrs_to_buffer(struct ext2_xattr_handle *handle,
+ struct ext2_xattr **pos,
+ void *entries_start,
+ unsigned int storage_size,
+ unsigned int value_offset_correction)
+{
+ struct ext2_xattr *x = *pos;
+ struct ext2_ext_attr_entry *e = entries_start;
+ void *end = entries_start + storage_size;
+ char *shortname;
+ unsigned int entry_size, value_size;
+ int idx, ret;
+
+ /* For all remaining x... */
+ for (; x < handle->attrs + handle->length; x++) {
+ if (!x->name)
+ continue;
+
+ /* Calculate index and shortname position */
+ shortname = x->name;
+ ret = find_ea_index(x->name, &shortname, &idx);
+
+ /* Calculate entry and value size */
+ entry_size = (sizeof(*e) + strlen(shortname) +
+ EXT2_EXT_ATTR_PAD - 1) &
+ ~(EXT2_EXT_ATTR_PAD - 1);
+ value_size = ((x->value_len + EXT2_EXT_ATTR_PAD - 1) /
+ EXT2_EXT_ATTR_PAD) * EXT2_EXT_ATTR_PAD;
+
+ /*
+ * Would entry collide with value?
+ * Note that we must leave sufficient room for a (u32)0 to
+ * mark the end of the entries.
+ */
+ if ((void *)e + entry_size + sizeof(__u32) > end - value_size)
+ break;
+
+ /* Fill out e appropriately */
+ e->e_name_len = strlen(shortname);
+ e->e_name_index = (ret ? idx : 0);
+ e->e_value_offs = end - value_size - (void *)entries_start +
+ value_offset_correction;
+ e->e_value_block = 0;
+ e->e_value_size = x->value_len;
+
+ /* Store name and value */
+ end -= value_size;
+ memcpy((void *)e + sizeof(*e), shortname, e->e_name_len);
+ memcpy(end, x->value, e->e_value_size);
+
+ e->e_hash = ext2fs_ext_attr_hash_entry(e, end);
+
+ e = EXT2_EXT_ATTR_NEXT(e);
+ *(__u32 *)e = 0;
+ }
+ *pos = x;
+
+ return 0;
+}
+
+errcode_t ext2fs_xattrs_write(struct ext2_xattr_handle *handle)
+{
+ struct ext2_xattr *x;
+ struct ext2_inode_large *inode;
+ void *start, *block_buf = NULL;
+ struct ext2_ext_attr_header *header;
+ __u32 ea_inode_magic;
+ blk64_t blk;
+ unsigned int storage_size;
+ unsigned int i, written;
+ errcode_t err;
+
+ if (!EXT2_HAS_COMPAT_FEATURE(handle->fs->super,
+ EXT2_FEATURE_COMPAT_EXT_ATTR))
+ return 0;
+
+ i = EXT2_INODE_SIZE(handle->fs->super);
+ if (i < sizeof(*inode))
+ i = sizeof(*inode);
+ err = ext2fs_get_memzero(i, &inode);
+ if (err)
+ return err;
+
+ err = ext2fs_read_inode_full(handle->fs, handle->ino,
+ (struct ext2_inode *)inode,
+ EXT2_INODE_SIZE(handle->fs->super));
+ if (err)
+ goto out;
+
+ x = handle->attrs;
+ /* Does the inode have size for EA? */
+ if (EXT2_INODE_SIZE(handle->fs->super) <= 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 = EXT2_INODE_SIZE(handle->fs->super) -
+ 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(handle, &x, start, storage_size, 0);
+ if (err)
+ goto out;
+
+ /* Are we done? */
+ if (x == handle->attrs + handle->length)
+ goto skip_ea_block;
+
+write_ea_block:
+ /* Write the EA block */
+ err = ext2fs_get_mem(handle->fs->blocksize, &block_buf);
+ if (err)
+ goto out;
+
+ storage_size = handle->fs->blocksize -
+ sizeof(struct ext2_ext_attr_header);
+ start = block_buf + sizeof(struct ext2_ext_attr_header);
+
+ err = write_xattrs_to_buffer(handle, &x, start, storage_size,
+ (void *)start - block_buf);
+ if (err)
+ goto out2;
+
+ if (x < handle->attrs + handle->length) {
+ err = EXT2_ET_EA_NO_SPACE;
+ goto out2;
+ }
+
+ if (block_buf) {
+ /* Write a header on the EA block */
+ 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(handle->fs, handle->ino, inode);
+ if (err)
+ goto out2;
+
+ /* Finally, write the new EA block */
+ blk = ext2fs_file_acl_block(handle->fs,
+ (struct ext2_inode *)inode);
+ err = ext2fs_write_ext_attr3(handle->fs, blk, block_buf,
+ handle->ino);
+ if (err)
+ goto out2;
+ }
+
+skip_ea_block:
+ blk = ext2fs_file_acl_block(handle->fs, (struct ext2_inode *)inode);
+ if (!block_buf && blk) {
+ /* xattrs shrunk, free the block */
+ ext2fs_file_acl_block_set(handle->fs,
+ (struct ext2_inode *)inode, 0);
+ err = ext2fs_iblk_sub_blocks(handle->fs,
+ (struct ext2_inode *)inode, 1);
+ if (err)
+ goto out;
+ ext2fs_block_alloc_stats2(handle->fs, blk, -1);
+ }
+
+ /* Write the inode */
+ err = ext2fs_write_inode_full(handle->fs, handle->ino,
+ (struct ext2_inode *)inode,
+ EXT2_INODE_SIZE(handle->fs->super));
+ if (err)
+ goto out2;
+
+out2:
+ ext2fs_free_mem(&block_buf);
+out:
+ ext2fs_free_mem(&inode);
+ handle->dirty = 0;
+ return err;
+}
+
+static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
+ struct ext2_ext_attr_entry *entries,
+ unsigned int storage_size,
+ void *value_start)
+{
+ struct ext2_xattr *x;
+ struct ext2_ext_attr_entry *entry;
+ const char *prefix;
+ void *ptr;
+ unsigned int remain, prefix_len;
+ errcode_t err;
+
+ x = handle->attrs;
+ while (x->name)
+ x++;
+
+ entry = entries;
+ while (!EXT2_EXT_IS_LAST_ENTRY(entry)) {
+ __u32 hash;
+
+ /* header eats this space */
+ remain -= sizeof(struct ext2_ext_attr_entry);
+
+ /* is attribute name valid? */
+ if (EXT2_EXT_ATTR_SIZE(entry->e_name_len) > remain)
+ return EXT2_ET_EA_BAD_NAME_LEN;
+
+ /* attribute len eats this space */
+ remain -= EXT2_EXT_ATTR_SIZE(entry->e_name_len);
+
+ /* check value size */
+ if (entry->e_value_size > remain)
+ return EXT2_ET_EA_BAD_VALUE_SIZE;
+
+ /* e_value_block must be 0 in inode's ea */
+ if (entry->e_value_block != 0)
+ return EXT2_ET_BAD_EA_BLOCK_NUM;
+
+ hash = ext2fs_ext_attr_hash_entry(entry, value_start +
+ entry->e_value_offs);
+
+ /* e_hash may be 0 in older inode's ea */
+ if (entry->e_hash != 0 && entry->e_hash != hash)
+ return EXT2_ET_BAD_EA_HASH;
+
+ remain -= entry->e_value_size;
+
+ /* Allocate space for more attrs? */
+ if (x == handle->attrs + handle->length) {
+ err = ext2fs_xattrs_expand(handle, 4);
+ if (err)
+ return err;
+ x = handle->attrs + handle->length - 4;
+ }
+
+ /* Extract name/value */
+ 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,
+ (void *)entry + sizeof(*entry),
+ entry->e_name_len);
+
+ err = ext2fs_get_mem(entry->e_value_size, &x->value);
+ if (err)
+ return err;
+ x->value_len = entry->e_value_size;
+ memcpy(x->value, value_start + entry->e_value_offs,
+ entry->e_value_size);
+ x++;
+ entry = EXT2_EXT_ATTR_NEXT(entry);
+ }
+
+ return 0;
+}
+
+errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle)
+{
+ struct ext2_xattr *attrs = NULL, *x;
+ unsigned int attrs_len;
+ struct ext2_inode_large *inode;
+ struct ext2_ext_attr_header *header;
+ __u32 ea_inode_magic;
+ unsigned int storage_size;
+ void *start, *block_buf = NULL;
+ blk64_t blk;
+ int i;
+ errcode_t err;
+
+ if (!EXT2_HAS_COMPAT_FEATURE(handle->fs->super,
+ EXT2_FEATURE_COMPAT_EXT_ATTR))
+ return 0;
+
+ i = EXT2_INODE_SIZE(handle->fs->super);
+ if (i < sizeof(*inode))
+ i = sizeof(*inode);
+ err = ext2fs_get_memzero(i, &inode);
+ if (err)
+ return err;
+
+ err = ext2fs_read_inode_full(handle->fs, handle->ino,
+ (struct ext2_inode *)inode,
+ EXT2_INODE_SIZE(handle->fs->super));
+ if (err)
+ goto out;
+
+ /* Does the inode have size for EA? */
+ if (EXT2_INODE_SIZE(handle->fs->super) <= EXT2_GOOD_OLD_INODE_SIZE +
+ inode->i_extra_isize +
+ sizeof(__u32))
+ goto read_ea_block;
+
+ /* Look for EA in the inode */
+ memcpy(&ea_inode_magic, ((char *) inode) + EXT2_GOOD_OLD_INODE_SIZE +
+ inode->i_extra_isize, sizeof(__u32));
+ if (ea_inode_magic == EXT2_EXT_ATTR_MAGIC) {
+ storage_size = EXT2_INODE_SIZE(handle->fs->super) -
+ 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 = read_xattrs_from_buffer(handle, start, storage_size,
+ start);
+ if (err)
+ goto out;
+ }
+
+read_ea_block:
+ /* Look for EA in a separate EA block */
+ blk = ext2fs_file_acl_block(handle->fs, (struct ext2_inode *)inode);
+ if (blk != 0) {
+ if ((blk < handle->fs->super->s_first_data_block) ||
+ (blk >= ext2fs_blocks_count(handle->fs->super))) {
+ err = EXT2_ET_BAD_EA_BLOCK_NUM;
+ goto out;
+ }
+
+ err = ext2fs_get_mem(handle->fs->blocksize, &block_buf);
+ if (err)
+ goto out;
+
+ err = ext2fs_read_ext_attr3(handle->fs, blk, block_buf,
+ handle->ino);
+ if (err)
+ goto out3;
+
+ header = (struct ext2_ext_attr_header *) block_buf;
+ if (header->h_magic != EXT2_EXT_ATTR_MAGIC) {
+ err = EXT2_ET_BAD_EA_HEADER;
+ goto out3;
+ }
+
+ if (header->h_blocks != 1) {
+ err = EXT2_ET_BAD_EA_HEADER;
+ goto out3;
+ }
+
+ /* Read EAs */
+ storage_size = handle->fs->blocksize -
+ sizeof(struct ext2_ext_attr_header);
+ start = block_buf + sizeof(struct ext2_ext_attr_header);
+ err = read_xattrs_from_buffer(handle, start, storage_size,
+ block_buf);
+ if (err)
+ goto out3;
+
+ ext2fs_free_mem(&block_buf);
+ }
+
+ ext2fs_free_mem(&block_buf);
+ ext2fs_free_mem(&inode);
+ return 0;
+
+out3:
+ ext2fs_free_mem(&block_buf);
+out:
+ ext2fs_free_mem(&inode);
+ return err;
+}
+
+#define XATTR_ABORT 1
+#define XATTR_CHANGED 2
+errcode_t ext2fs_xattrs_iterate(struct ext2_xattr_handle *h,
+ int (*func)(char *name, char *value,
+ void *data),
+ void *data)
+{
+ struct ext2_xattr *x;
+ errcode_t err;
+ int ret;
+
+ for (x = h->attrs; x < h->attrs + h->length; x++) {
+ if (!x->name)
+ continue;
+
+ ret = func(x->name, x->value, data);
+ if (ret & XATTR_CHANGED)
+ h->dirty = 1;
+ if (ret & XATTR_ABORT)
+ return 0;
+ }
+
+ return 0;
+}
+
+errcode_t ext2fs_xattr_get(struct ext2_xattr_handle *h, const char *key,
+ void **value, unsigned int *value_len)
+{
+ struct ext2_xattr *x;
+ void *val;
+ errcode_t err;
+
+ for (x = h->attrs; x < h->attrs + h->length; x++) {
+ if (!x->name)
+ continue;
+
+ if (strcmp(x->name, key) == 0) {
+ err = ext2fs_get_mem(x->value_len, &val);
+ if (err)
+ return err;
+ memcpy(val, x->value, x->value_len);
+ *value = val;
+ *value_len = x->value_len;
+ return 0;
+ }
+ }
+
+ return EXT2_ET_EA_KEY_NOT_FOUND;
+}
+
+errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *handle,
+ const char *key,
+ const void *value,
+ unsigned int value_len)
+{
+ struct ext2_xattr *x, *last_empty;
+ char *new_value;
+ errcode_t err;
+
+ last_empty = NULL;
+ for (x = handle->attrs; x < handle->attrs + handle->length; x++) {
+ if (!x->name) {
+ last_empty = x;
+ continue;
+ }
+
+ /* Replace xattr */
+ if (strcmp(x->name, key) == 0) {
+ err = ext2fs_get_mem(value_len, &new_value);
+ if (err)
+ return err;
+ memcpy(new_value, value, value_len);
+ ext2fs_free_mem(&x->value);
+ x->value = new_value;
+ x->value_len = value_len;
+ handle->dirty = 1;
+ return 0;
+ }
+ }
+
+ /* Add attr to empty slot */
+ if (last_empty) {
+ err = ext2fs_get_mem(strlen(key) + 1, &last_empty->name);
+ if (err)
+ return err;
+ strcpy(last_empty->name, key);
+
+ err = ext2fs_get_mem(value_len, &last_empty->value);
+ if (err)
+ return err;
+ memcpy(last_empty->value, value, value_len);
+ last_empty->value_len = value_len;
+ handle->dirty = 1;
+ return 0;
+ }
+
+ /* Expand array, append slot */
+ err = ext2fs_xattrs_expand(handle, 4);
+ if (err)
+ return err;
+
+ x = handle->attrs + handle->length - 4;
+ err = ext2fs_get_mem(strlen(key) + 1, &x->name);
+ if (err)
+ return err;
+ strcpy(x->name, key);
+
+ err = ext2fs_get_mem(value_len, &x->value);
+ if (err)
+ return err;
+ memcpy(x->value, value, value_len);
+ x->value_len = value_len;
+ handle->dirty = 1;
+ return 0;
+}
+
+errcode_t ext2fs_xattr_remove(struct ext2_xattr_handle *handle,
+ const char *key)
+{
+ struct ext2_xattr *x;
+ errcode_t err;
+
+ for (x = handle->attrs; x < handle->attrs + handle->length; x++) {
+ if (!x->name)
+ continue;
+
+ if (strcmp(x->name, key) == 0) {
+ ext2fs_free_mem(&x->name);
+ ext2fs_free_mem(&x->value);
+ x->value_len = 0;
+ handle->dirty = 1;
+ return 0;
+ }
+ }
+
+ return EXT2_ET_EA_KEY_NOT_FOUND;
+}
+
+errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
+ struct ext2_xattr_handle **handle)
+{
+ struct ext2_xattr_handle *h;
+ errcode_t err;
+
+ err = ext2fs_get_memzero(sizeof(*h), &h);
+ if (err)
+ return err;
+
+ h->length = 4;
+ err = ext2fs_get_arrayzero(h->length, sizeof(struct ext2_xattr),
+ &h->attrs);
+ if (err) {
+ ext2fs_free_mem(&h);
+ return err;
+ }
+ h->ino = ino;
+ h->fs = fs;
+ *handle = h;
+ return 0;
+}
+
+errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle)
+{
+ unsigned int i;
+ struct ext2_xattr_handle *h = *handle;
+ struct ext2_xattr *a = h->attrs;
+ errcode_t err;
+
+ if (h->dirty) {
+ err = ext2fs_xattrs_write(h);
+ if (err)
+ return err;
+ }
+
+ for (i = 0; i < h->length; i++) {
+ if (a[i].name)
+ ext2fs_free_mem(&a[i].name);
+ if (a[i].value)
+ ext2fs_free_mem(&a[i].value);
+ }
+
+ ext2fs_free_mem(&h->attrs);
+ ext2fs_free_mem(handle);
+ return 0;
+}
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