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grub/grub-core/fs/hfspluscomp.c
Vladimir Serbinenko 2e238b3708 Make grub_zlib_decompress handle incomplete chunks. 
Fixes squash4.
2013-12-18 23:39:49 +01:00

317 lines
8.4 KiB
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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2012 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
/* HFS+ is documented at http://developer.apple.com/technotes/tn/tn1150.html */
#include <grub/hfsplus.h>
#include <grub/dl.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/deflate.h>
#include <grub/file.h>
GRUB_MOD_LICENSE ("GPLv3+");
/* big-endian. */
struct grub_hfsplus_compress_header1
{
grub_uint32_t header_size;
grub_uint32_t end_descriptor_offset;
grub_uint32_t total_compressed_size_including_seek_blocks_and_header2;
grub_uint32_t value_0x32;
grub_uint8_t unused[0xf0];
} GRUB_PACKED;
/* big-endian. */
struct grub_hfsplus_compress_header2
{
grub_uint32_t total_compressed_size_including_seek_blocks;
} GRUB_PACKED;
/* little-endian. */
struct grub_hfsplus_compress_header3
{
grub_uint32_t num_chunks;
} GRUB_PACKED;
/* little-endian. */
struct grub_hfsplus_compress_block_descriptor
{
grub_uint32_t offset;
grub_uint32_t size;
};
struct grub_hfsplus_compress_end_descriptor
{
grub_uint8_t always_the_same[50];
} GRUB_PACKED;
struct grub_hfsplus_attr_header
{
grub_uint8_t unused[3];
grub_uint8_t type;
grub_uint32_t unknown[1];
grub_uint64_t size;
} GRUB_PACKED;
struct grub_hfsplus_compress_attr
{
grub_uint32_t magic;
grub_uint32_t type;
grub_uint32_t uncompressed_inline_size;
grub_uint32_t always_0;
} GRUB_PACKED;
enum
{
HFSPLUS_COMPRESSION_INLINE = 3,
HFSPLUS_COMPRESSION_RESOURCE = 4
};
static int
grub_hfsplus_cmp_attrkey (struct grub_hfsplus_key *keya,
struct grub_hfsplus_key_internal *keyb)
{
struct grub_hfsplus_attrkey *attrkey_a = &keya->attrkey;
struct grub_hfsplus_attrkey_internal *attrkey_b = &keyb->attrkey;
grub_uint32_t aparent = grub_be_to_cpu32 (attrkey_a->cnid);
grub_size_t len;
int diff;
if (aparent > attrkey_b->cnid)
return 1;
if (aparent < attrkey_b->cnid)
return -1;
len = grub_be_to_cpu16 (attrkey_a->namelen);
if (len > attrkey_b->namelen)
len = attrkey_b->namelen;
/* Since it's big-endian memcmp gives the same result as manually comparing
uint16_t but may be faster. */
diff = grub_memcmp (attrkey_a->name, attrkey_b->name,
len * sizeof (attrkey_a->name[0]));
if (diff == 0)
diff = grub_be_to_cpu16 (attrkey_a->namelen) - attrkey_b->namelen;
return diff;
}
#define HFSPLUS_COMPRESS_BLOCK_SIZE 65536
static grub_ssize_t
hfsplus_read_compressed_real (struct grub_hfsplus_file *node,
grub_off_t pos, grub_size_t len, char *buf)
{
char *tmp_buf = 0;
grub_size_t len0 = len;
if (node->compressed == 1)
{
grub_memcpy (buf, node->cbuf + pos, len);
if (grub_file_progress_hook && node->file)
grub_file_progress_hook (0, 0, len, node->file);
return len;
}
while (len)
{
grub_uint32_t block = pos / HFSPLUS_COMPRESS_BLOCK_SIZE;
grub_size_t curlen = HFSPLUS_COMPRESS_BLOCK_SIZE
- (pos % HFSPLUS_COMPRESS_BLOCK_SIZE);
if (curlen > len)
curlen = len;
if (node->cbuf_block != block)
{
grub_uint32_t sz = grub_le_to_cpu32 (node->compress_index[block].size);
grub_size_t ts;
if (!tmp_buf)
tmp_buf = grub_malloc (HFSPLUS_COMPRESS_BLOCK_SIZE);
if (!tmp_buf)
return -1;
if (grub_hfsplus_read_file (node, 0, 0,
grub_le_to_cpu32 (node->compress_index[block].start) + 0x104,
sz, tmp_buf)
!= (grub_ssize_t) sz)
{
grub_free (tmp_buf);
return -1;
}
ts = HFSPLUS_COMPRESS_BLOCK_SIZE;
if (ts > node->size - (pos & ~(HFSPLUS_COMPRESS_BLOCK_SIZE)))
ts = node->size - (pos & ~(HFSPLUS_COMPRESS_BLOCK_SIZE));
if (grub_zlib_decompress (tmp_buf, sz, 0,
node->cbuf, ts) != (grub_ssize_t) ts)
{
if (!grub_errno)
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
"premature end of compressed");
grub_free (tmp_buf);
return -1;
}
node->cbuf_block = block;
}
grub_memcpy (buf, node->cbuf + (pos % HFSPLUS_COMPRESS_BLOCK_SIZE),
curlen);
if (grub_file_progress_hook && node->file)
grub_file_progress_hook (0, 0, curlen, node->file);
buf += curlen;
pos += curlen;
len -= curlen;
}
grub_free (tmp_buf);
return len0;
}
static grub_err_t
hfsplus_open_compressed_real (struct grub_hfsplus_file *node)
{
grub_err_t err;
struct grub_hfsplus_btnode *attr_node;
grub_off_t attr_off;
struct grub_hfsplus_key_internal key;
struct grub_hfsplus_attr_header *attr_head;
struct grub_hfsplus_compress_attr *cmp_head;
#define c grub_cpu_to_be16_compile_time
const grub_uint16_t compress_attr_name[] =
{
c('c'), c('o'), c('m'), c('.'), c('a'), c('p'), c('p'), c('l'), c('e'),
c('.'), c('d'), c('e'), c('c'), c('m'), c('p'), c('f'), c('s') };
#undef c
if (node->size)
return 0;
key.attrkey.cnid = node->fileid;
key.attrkey.namelen = sizeof (compress_attr_name) / sizeof (compress_attr_name[0]);
key.attrkey.name = compress_attr_name;
err = grub_hfsplus_btree_search (&node->data->attr_tree, &key,
grub_hfsplus_cmp_attrkey,
&attr_node, &attr_off);
if (err || !attr_node)
{
grub_errno = 0;
return 0;
}
attr_head = (struct grub_hfsplus_attr_header *)
((char *) grub_hfsplus_btree_recptr (&node->data->attr_tree,
attr_node, attr_off)
+ sizeof (struct grub_hfsplus_attrkey) + sizeof (compress_attr_name));
if (attr_head->type != 0x10
|| !(attr_head->size & grub_cpu_to_be64_compile_time(~0xfULL)))
{
grub_free (attr_node);
return 0;
}
cmp_head = (struct grub_hfsplus_compress_attr *) (attr_head + 1);
if (cmp_head->magic != grub_cpu_to_be32_compile_time (0x66706d63))
{
grub_free (attr_node);
return 0;
}
node->size = grub_le_to_cpu32 (cmp_head->uncompressed_inline_size);
if (cmp_head->type == grub_cpu_to_le32_compile_time (HFSPLUS_COMPRESSION_RESOURCE))
{
grub_uint32_t index_size;
node->compressed = 2;
if (grub_hfsplus_read_file (node, 0, 0,
0x104, sizeof (index_size),
(char *) &index_size)
!= 4)
{
node->compressed = 0;
grub_free (attr_node);
grub_errno = 0;
return 0;
}
node->compress_index_size = grub_le_to_cpu32 (index_size);
node->compress_index = grub_malloc (node->compress_index_size
* sizeof (node->compress_index[0]));
if (!node->compress_index)
{
node->compressed = 0;
grub_free (attr_node);
return grub_errno;
}
if (grub_hfsplus_read_file (node, 0, 0,
0x104 + sizeof (index_size),
node->compress_index_size
* sizeof (node->compress_index[0]),
(char *) node->compress_index)
!= (grub_ssize_t) (node->compress_index_size
* sizeof (node->compress_index[0])))
{
node->compressed = 0;
grub_free (attr_node);
grub_free (node->compress_index);
grub_errno = 0;
return 0;
}
node->cbuf_block = -1;
node->cbuf = grub_malloc (HFSPLUS_COMPRESS_BLOCK_SIZE);
grub_free (attr_node);
if (!node->cbuf)
{
node->compressed = 0;
grub_free (node->compress_index);
return grub_errno;
}
return 0;
}
if (cmp_head->type != HFSPLUS_COMPRESSION_INLINE)
{
grub_free (attr_node);
return 0;
}
node->cbuf = grub_malloc (node->size);
if (!node->cbuf)
return grub_errno;
if (grub_zlib_decompress ((char *) (cmp_head + 1),
grub_cpu_to_be64 (attr_head->size)
- sizeof (*cmp_head), 0,
node->cbuf, node->size)
!= (grub_ssize_t) node->size)
{
if (!grub_errno)
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
"premature end of compressed");
return grub_errno;
}
node->compressed = 1;
return 0;
}
GRUB_MOD_INIT(hfspluscomp)
{
grub_hfsplus_open_compressed = hfsplus_open_compressed_real;
grub_hfsplus_read_compressed = hfsplus_read_compressed_real;
}
GRUB_MOD_FINI(hfspluscomp)
{
grub_hfsplus_open_compressed = 0;
grub_hfsplus_read_compressed = 0;
}
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