/*
* Read and decompress the xattr id table and the xattr metadata.
* This is cached in memory for later use by get_xattr()
*/
int read_xattrs_from_disk(int fd, struct squashfs_super_block *sBlk) {
int res, bytes, i, indexes, index_bytes, ids;
long long *index, start, end;
struct squashfs_xattr_table id_table;
TRACE("read_xattrs_from_disk\n");
if (sBlk->xattr_id_table_start == SQUASHFS_INVALID_BLK)
return SQUASHFS_INVALID_BLK;
/*
* Read xattr id table, containing start of xattr metadata and the
* number of xattrs in the file system
*/
res = read_fs_bytes(fd, sBlk->xattr_id_table_start, sizeof(id_table), &id_table);
if (res == 0)
return 0;
SQUASHFS_INSWAP_XATTR_TABLE(&id_table);
/*
* Allocate and read the index to the xattr id table metadata
* blocks
*/
ids = id_table.xattr_ids;
xattr_table_start = id_table.xattr_table_start;
index_bytes = SQUASHFS_XATTR_BLOCK_BYTES(ids);
indexes = SQUASHFS_XATTR_BLOCKS(ids);
index = malloc(index_bytes);
if (index == NULL)
MEM_ERROR();
res = read_fs_bytes(fd, sBlk->xattr_id_table_start + sizeof(id_table), index_bytes, index);
if (res == 0)
goto failed1;
SQUASHFS_INSWAP_LONG_LONGS(index, indexes);
/*
* Allocate enough space for the uncompressed xattr id table, and
* read and decompress it
*/
bytes = SQUASHFS_XATTR_BYTES(ids);
xattr_ids = malloc(bytes);
if (xattr_ids == NULL)
MEM_ERROR();
for (i = 0; i < indexes; i++) {
int expected = (i + 1) != indexes ? SQUASHFS_METADATA_SIZE : bytes & (SQUASHFS_METADATA_SIZE - 1);
int length = read_block(fd, index[i], NULL, expected,
((unsigned char *)xattr_ids) + (i * SQUASHFS_METADATA_SIZE));
TRACE("Read xattr id table block %d, from 0x%llx, length " "%d\n", i, index[i], length);
if (length == 0) {
ERROR("Failed to read xattr id table block %d, " "from 0x%llx, length %d\n", i, index[i], length);
goto failed2;
}
}
/*
* Read and decompress the xattr metadata
*
* Note the first xattr id table metadata block is immediately after
* the last xattr metadata block, so we can use index[0] to work out
* the end of the xattr metadata
*/
start = xattr_table_start;
end = index[0];
for (i = 0; start < end; i++) {
int length;
xattrs = realloc(xattrs, (i + 1) * SQUASHFS_METADATA_SIZE);
if (xattrs == NULL)
MEM_ERROR();
/* store mapping from location of compressed block in fs ->
* location of uncompressed block in memory */
save_xattr_block(start, i * SQUASHFS_METADATA_SIZE);
length = read_block(fd, start, &start, 0, ((unsigned char *)xattrs) + (i * SQUASHFS_METADATA_SIZE));
TRACE("Read xattr block %d, length %d\n", i, length);
if (length == 0) {
ERROR("Failed to read xattr block %d\n", i);
goto failed3;
}
/*
* If this is not the last metadata block in the xattr metadata
* then it should be SQUASHFS_METADATA_SIZE in size.
* Note, we can't use expected in read_block() above for this
* because we don't know if this is the last block until
* after reading.
*/
if (start != end && length != SQUASHFS_METADATA_SIZE) {
ERROR("Xattr block %d should be %d bytes in length, " "it is %d bytes\n", i, SQUASHFS_METADATA_SIZE, length);
goto failed3;
}
}
/* swap if necessary the xattr id entries */
for (i = 0; i < ids; i++)
SQUASHFS_INSWAP_XATTR_ID(&xattr_ids[i]);
free(index);
return ids;
failed3:
free(xattrs);
failed2:
free(xattr_ids);
failed1:
free(index);
return 0;
}
/*
* Read and decompress the xattr id table and the xattr metadata.
* This is cached in memory for later use by get_xattr()
*/
int read_xattrs_from_disk(int fd, struct squashfs_super_block *sBlk)
{
int res, bytes, i, indexes, index_bytes, ids;
long long *index, start, end;
struct squashfs_xattr_table id_table;
TRACE("read_xattrs_from_disk\n");
if(sBlk->xattr_id_table_start == SQUASHFS_INVALID_BLK)
return SQUASHFS_INVALID_BLK;
/*
* Read xattr id table, containing start of xattr metadata and the
* number of xattrs in the file system
*/
res = read_fs_bytes(fd, sBlk->xattr_id_table_start, sizeof(id_table),
&id_table);
if(res == 0)
return 0;
SQUASHFS_INSWAP_XATTR_TABLE(&id_table);
/*
* Allocate and read the index to the xattr id table metadata
* blocks
*/
ids = id_table.xattr_ids;
xattr_table_start = id_table.xattr_table_start;
index_bytes = SQUASHFS_XATTR_BLOCK_BYTES(ids);
indexes = SQUASHFS_XATTR_BLOCKS(ids);
index = malloc(index_bytes);
if(index == NULL) {
ERROR("Failed to allocate index array\n");
return 0;
}
res = read_fs_bytes(fd, sBlk->xattr_id_table_start + sizeof(id_table),
index_bytes, index);
if(res ==0)
goto failed1;
SQUASHFS_INSWAP_LONG_LONGS(index, indexes);
/*
* Allocate enough space for the uncompressed xattr id table, and
* read and decompress it
*/
bytes = SQUASHFS_XATTR_BYTES(ids);
xattr_ids = malloc(bytes);
if(xattr_ids == NULL) {
ERROR("Failed to allocate xattr id table\n");
goto failed1;
}
for(i = 0; i < indexes; i++) {
int length = read_block(fd, index[i], NULL,
((unsigned char *) xattr_ids) +
(i * SQUASHFS_METADATA_SIZE));
TRACE("Read xattr id table block %d, from 0x%llx, length "
"%d\n", i, index[i], length);
if(length == 0) {
ERROR("Failed to read xattr id table block %d, "
"from 0x%llx, length %d\n", i, index[i],
length);
goto failed2;
}
}
/*
* Read and decompress the xattr metadata
*
* Note the first xattr id table metadata block is immediately after
* the last xattr metadata block, so we can use index[0] to work out
* the end of the xattr metadata
*/
start = xattr_table_start;
end = index[0];
for(i = 0; start < end; i++) {
int length;
void *x = realloc(xattrs, (i + 1) * SQUASHFS_METADATA_SIZE);
if(x == NULL) {
ERROR("Failed to realloc xattr data\n");
goto failed3;
}
xattrs = x;
/* store mapping from location of compressed block in fs ->
* location of uncompressed block in memory */
res = save_xattr_block(start, i * SQUASHFS_METADATA_SIZE);
if(res == -1)
goto failed3;
length = read_block(fd, start, &start,
((unsigned char *) xattrs) +
(i * SQUASHFS_METADATA_SIZE));
TRACE("Read xattr block %d, length %d\n", i, length);
if(length == 0) {
ERROR("Failed to read xattr block %d\n", i);
goto failed3;
}
}
/* swap if necessary the xattr id entries */
for(i = 0; i < ids; i++)
SQUASHFS_INSWAP_XATTR_ID(&xattr_ids[i]);
free(index);
return ids;
failed3:
free(xattrs);
failed2:
free(xattr_ids);
failed1:
free(index);
return 0;
}
