Use xz-embedded for b64xz

This commit is contained in:
topjohnwu 2018-08-10 04:37:38 +08:00
parent 5bac442b18
commit 1def9b301b
13 changed files with 2976 additions and 45 deletions

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@ -300,11 +300,11 @@ def gen_update_binary():
binary = os.path.join('native', 'out', 'armeabi-v7a', 'busybox')
with open(binary, 'rb') as busybox:
update_bin.append('\'\nBB_ARM=')
update_bin.append(base64.b64encode(lzma.compress(busybox.read(), preset=9)).decode('ascii'))
update_bin.append(base64.b64encode(lzma.compress(busybox.read(), preset=9, check=lzma.CHECK_NONE)).decode('ascii'))
binary = os.path.join('native', 'out', 'x86', 'busybox')
with open(binary, 'rb') as busybox:
update_bin.append('\nBB_X86=')
update_bin.append(base64.b64encode(lzma.compress(busybox.read(), preset=9)).decode('ascii'))
update_bin.append(base64.b64encode(lzma.compress(busybox.read(), preset=9, check=lzma.CHECK_NONE)).decode('ascii'))
update_bin.append('\n')
with open(os.path.join('scripts', 'update_binary.sh'), 'r') as script:
update_bin.append(script.read())

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@ -14,7 +14,7 @@ android {
externalNativeBuild {
ndkBuild {
// Pass arguments to ndk-build.
arguments('B_MAGISK=1', 'B_INIT=1', 'B_BOOT=1', 'MAGISK_VERSION=debug',
arguments('B_MAGISK=1', 'B_INIT=1', 'B_BOOT=1', 'B_BXZ=1', 'MAGISK_VERSION=debug',
'MAGISK_VER_CODE=99999', 'MAGISK_DEBUG=-DMAGISK_DEBUG')
}
}

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@ -73,8 +73,7 @@ LOCAL_C_INCLUDES := \
jni/magiskpolicy \
out \
out/$(TARGET_ARCH_ABI) \
$(LIBSEPOL) \
$(LIBLZMA)
$(LIBSEPOL)
LOCAL_SRC_FILES := \
core/magiskinit.c \
@ -126,8 +125,8 @@ ifdef B_BXZ
# b64xz
include $(CLEAR_VARS)
LOCAL_MODULE := b64xz
LOCAL_STATIC_LIBRARIES := liblzma
LOCAL_C_INCLUDES := $(LIBLZMA)
LOCAL_STATIC_LIBRARIES := libxz
LOCAL_C_INCLUDES := $(EXT_PATH)/include
LOCAL_SRC_FILES := b64xz.c
LOCAL_LDFLAGS := -static
include $(BUILD_EXECUTABLE)

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@ -1,21 +1,17 @@
/* b64xz.c - Base64-XZ Extractor
*
* This program expects data from stdin. The data should be compressed with xz and
* then encoded into base64 format. What b64xz does is basically the reverse of the
* mentioned process: decode base64 to uint8_ts, decompress xz, then dump to stdout
* This program converts data from stdin to stdout.
* The input should be compressed with xz (integrity check only support CRC32 or none) and then
* encoded into base64 format. What b64xz does is basically the reverse of the
* mentioned process: decode base64 to bytes, decompress xz, then dump to stdout
*
* The compiled binary will be hex-dumped into update-binary
* Busybox will be xz-compressed, base64 encoded and dumped into update-binary
* This program is to recover busybox for Magisk installation environment
*
* I intentionally removed stdio. This will result in a smaller binary size because
* all I/O are handled by system calls (read/write) instead of libc wrappers
*/
#include <unistd.h>
#include <lzma.h>
#define BUFSIZE 8192
#include <xz.h>
static const char trans_tbl[] =
"|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW$$$$$$XYZ[\\]^_`abcdefghijklmnopq";
@ -26,37 +22,39 @@ static void decodeblock(uint8_t* in, uint8_t* out) {
out[2] = (uint8_t)(((in[2] << 6) & 0xc0) | in[3]);
}
static int unxz(lzma_stream *strm, void *buf, size_t size) {
lzma_ret ret = 0;
uint8_t out[BUFSIZE];
strm->next_in = buf;
strm->avail_in = size;
static int unxz(struct xz_dec *dec, void *buf, unsigned size) {
uint8_t out[8192];
struct xz_buf b = {
.in = buf,
.in_pos = 0,
.in_size = size,
.out = out,
.out_pos = 0,
.out_size = sizeof(out)
};
enum xz_ret ret;
do {
strm->next_out = out;
strm->avail_out = sizeof(out);
ret = lzma_code(strm, LZMA_RUN);
write(STDOUT_FILENO, out, sizeof(out) - strm->avail_out);
} while (strm->avail_out == 0 && ret == LZMA_OK);
if (ret != LZMA_OK && ret != LZMA_STREAM_END)
write(STDERR_FILENO, "LZMA error!\n", 13);
return ret;
ret = xz_dec_run(dec, &b);
if (ret != XZ_OK && ret != XZ_STREAM_END)
return 1;
write(STDOUT_FILENO, out, b.out_pos);
b.out_pos = 0;
} while (b.in_pos != size);
return 0;
}
int main(int argc, char const* argv[]) {
if (argc > 1)
return 0;
uint8_t in[4], buf[BUFSIZE];
int len = 0, pos = 0;
uint8_t in[4], buf[6144];
unsigned len = 0, pos = 0;
char c;
// Setup lzma stream
lzma_stream strm = LZMA_STREAM_INIT;
if (lzma_auto_decoder(&strm, UINT64_MAX, 0) != LZMA_OK) {
write(STDERR_FILENO, "Unable to init lzma stream\n", 28);
xz_crc32_init();
struct xz_dec *dec = xz_dec_init(XZ_DYNALLOC, 1 << 26);
if (dec == NULL)
return 1;
}
while (read(STDIN_FILENO, &c, sizeof(c)) == 1) {
c = ((c < 43 || c > 122) ? -1 : (trans_tbl[c - 43] == '$' ? -1 : trans_tbl[c - 43] - 62));
@ -67,17 +65,14 @@ int main(int argc, char const* argv[]) {
len = 0;
decodeblock(in, buf + pos);
pos += 3;
if (pos > sizeof(buf) - 3) {
// Buffer is full, unxz
if (unxz(&strm, buf, pos))
if (pos == sizeof(buf)) {
if (unxz(dec, buf, pos))
return 1;
pos = 0;
}
}
if (pos) {
if (unxz(&strm, buf, pos))
return 1;
}
lzma_end(&strm);
if (pos && unxz(dec, buf, pos))
return 1;
xz_dec_end(dec);
return 0;
}

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@ -14,6 +14,16 @@ LOCAL_C_INCLUDES := $(LIBSELINUX)
LOCAL_SRC_FILES := stubs/selinux_stub.c
include $(BUILD_SHARED_LIBRARY)
# libxz.a
include $(CLEAR_VARS)
LOCAL_MODULE:= libxz
LOCAL_C_INCLUDES := $(EXT_PATH)/include
LOCAL_SRC_FILES := \
xz-embedded/xz_crc32.c \
xz-embedded/xz_dec_lzma2.c \
xz-embedded/xz_dec_stream.c
include $(BUILD_STATIC_LIBRARY)
# libmincrypt.a
include $(CLEAR_VARS)
LOCAL_MODULE:= libmincrypt

304
native/jni/external/include/xz.h vendored Normal file
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@ -0,0 +1,304 @@
/*
* XZ decompressor
*
* Authors: Lasse Collin <lasse.collin@tukaani.org>
* Igor Pavlov <http://7-zip.org/>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#ifndef XZ_H
#define XZ_H
#ifdef __KERNEL__
# include <linux/stddef.h>
# include <linux/types.h>
#else
# include <stddef.h>
# include <stdint.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
/* In Linux, this is used to make extern functions static when needed. */
#ifndef XZ_EXTERN
# define XZ_EXTERN extern
#endif
/**
* enum xz_mode - Operation mode
*
* @XZ_SINGLE: Single-call mode. This uses less RAM than
* than multi-call modes, because the LZMA2
* dictionary doesn't need to be allocated as
* part of the decoder state. All required data
* structures are allocated at initialization,
* so xz_dec_run() cannot return XZ_MEM_ERROR.
* @XZ_PREALLOC: Multi-call mode with preallocated LZMA2
* dictionary buffer. All data structures are
* allocated at initialization, so xz_dec_run()
* cannot return XZ_MEM_ERROR.
* @XZ_DYNALLOC: Multi-call mode. The LZMA2 dictionary is
* allocated once the required size has been
* parsed from the stream headers. If the
* allocation fails, xz_dec_run() will return
* XZ_MEM_ERROR.
*
* It is possible to enable support only for a subset of the above
* modes at compile time by defining XZ_DEC_SINGLE, XZ_DEC_PREALLOC,
* or XZ_DEC_DYNALLOC. The xz_dec kernel module is always compiled
* with support for all operation modes, but the preboot code may
* be built with fewer features to minimize code size.
*/
enum xz_mode {
XZ_SINGLE,
XZ_PREALLOC,
XZ_DYNALLOC
};
/**
* enum xz_ret - Return codes
* @XZ_OK: Everything is OK so far. More input or more
* output space is required to continue. This
* return code is possible only in multi-call mode
* (XZ_PREALLOC or XZ_DYNALLOC).
* @XZ_STREAM_END: Operation finished successfully.
* @XZ_UNSUPPORTED_CHECK: Integrity check type is not supported. Decoding
* is still possible in multi-call mode by simply
* calling xz_dec_run() again.
* Note that this return value is used only if
* XZ_DEC_ANY_CHECK was defined at build time,
* which is not used in the kernel. Unsupported
* check types return XZ_OPTIONS_ERROR if
* XZ_DEC_ANY_CHECK was not defined at build time.
* @XZ_MEM_ERROR: Allocating memory failed. This return code is
* possible only if the decoder was initialized
* with XZ_DYNALLOC. The amount of memory that was
* tried to be allocated was no more than the
* dict_max argument given to xz_dec_init().
* @XZ_MEMLIMIT_ERROR: A bigger LZMA2 dictionary would be needed than
* allowed by the dict_max argument given to
* xz_dec_init(). This return value is possible
* only in multi-call mode (XZ_PREALLOC or
* XZ_DYNALLOC); the single-call mode (XZ_SINGLE)
* ignores the dict_max argument.
* @XZ_FORMAT_ERROR: File format was not recognized (wrong magic
* bytes).
* @XZ_OPTIONS_ERROR: This implementation doesn't support the requested
* compression options. In the decoder this means
* that the header CRC32 matches, but the header
* itself specifies something that we don't support.
* @XZ_DATA_ERROR: Compressed data is corrupt.
* @XZ_BUF_ERROR: Cannot make any progress. Details are slightly
* different between multi-call and single-call
* mode; more information below.
*
* In multi-call mode, XZ_BUF_ERROR is returned when two consecutive calls
* to XZ code cannot consume any input and cannot produce any new output.
* This happens when there is no new input available, or the output buffer
* is full while at least one output byte is still pending. Assuming your
* code is not buggy, you can get this error only when decoding a compressed
* stream that is truncated or otherwise corrupt.
*
* In single-call mode, XZ_BUF_ERROR is returned only when the output buffer
* is too small or the compressed input is corrupt in a way that makes the
* decoder produce more output than the caller expected. When it is
* (relatively) clear that the compressed input is truncated, XZ_DATA_ERROR
* is used instead of XZ_BUF_ERROR.
*/
enum xz_ret {
XZ_OK,
XZ_STREAM_END,
XZ_UNSUPPORTED_CHECK,
XZ_MEM_ERROR,
XZ_MEMLIMIT_ERROR,
XZ_FORMAT_ERROR,
XZ_OPTIONS_ERROR,
XZ_DATA_ERROR,
XZ_BUF_ERROR
};
/**
* struct xz_buf - Passing input and output buffers to XZ code
* @in: Beginning of the input buffer. This may be NULL if and only
* if in_pos is equal to in_size.
* @in_pos: Current position in the input buffer. This must not exceed
* in_size.
* @in_size: Size of the input buffer
* @out: Beginning of the output buffer. This may be NULL if and only
* if out_pos is equal to out_size.
* @out_pos: Current position in the output buffer. This must not exceed
* out_size.
* @out_size: Size of the output buffer
*
* Only the contents of the output buffer from out[out_pos] onward, and
* the variables in_pos and out_pos are modified by the XZ code.
*/
struct xz_buf {
const uint8_t *in;
size_t in_pos;
size_t in_size;
uint8_t *out;
size_t out_pos;
size_t out_size;
};
/**
* struct xz_dec - Opaque type to hold the XZ decoder state
*/
struct xz_dec;
/**
* xz_dec_init() - Allocate and initialize a XZ decoder state
* @mode: Operation mode
* @dict_max: Maximum size of the LZMA2 dictionary (history buffer) for
* multi-call decoding. This is ignored in single-call mode
* (mode == XZ_SINGLE). LZMA2 dictionary is always 2^n bytes
* or 2^n + 2^(n-1) bytes (the latter sizes are less common
* in practice), so other values for dict_max don't make sense.
* In the kernel, dictionary sizes of 64 KiB, 128 KiB, 256 KiB,
* 512 KiB, and 1 MiB are probably the only reasonable values,
* except for kernel and initramfs images where a bigger
* dictionary can be fine and useful.
*
* Single-call mode (XZ_SINGLE): xz_dec_run() decodes the whole stream at
* once. The caller must provide enough output space or the decoding will
* fail. The output space is used as the dictionary buffer, which is why
* there is no need to allocate the dictionary as part of the decoder's
* internal state.
*
* Because the output buffer is used as the workspace, streams encoded using
* a big dictionary are not a problem in single-call mode. It is enough that
* the output buffer is big enough to hold the actual uncompressed data; it
* can be smaller than the dictionary size stored in the stream headers.
*
* Multi-call mode with preallocated dictionary (XZ_PREALLOC): dict_max bytes
* of memory is preallocated for the LZMA2 dictionary. This way there is no
* risk that xz_dec_run() could run out of memory, since xz_dec_run() will
* never allocate any memory. Instead, if the preallocated dictionary is too
* small for decoding the given input stream, xz_dec_run() will return
* XZ_MEMLIMIT_ERROR. Thus, it is important to know what kind of data will be
* decoded to avoid allocating excessive amount of memory for the dictionary.
*
* Multi-call mode with dynamically allocated dictionary (XZ_DYNALLOC):
* dict_max specifies the maximum allowed dictionary size that xz_dec_run()
* may allocate once it has parsed the dictionary size from the stream
* headers. This way excessive allocations can be avoided while still
* limiting the maximum memory usage to a sane value to prevent running the
* system out of memory when decompressing streams from untrusted sources.
*
* On success, xz_dec_init() returns a pointer to struct xz_dec, which is
* ready to be used with xz_dec_run(). If memory allocation fails,
* xz_dec_init() returns NULL.
*/
XZ_EXTERN struct xz_dec *xz_dec_init(enum xz_mode mode, uint32_t dict_max);
/**
* xz_dec_run() - Run the XZ decoder
* @s: Decoder state allocated using xz_dec_init()
* @b: Input and output buffers
*
* The possible return values depend on build options and operation mode.
* See enum xz_ret for details.
*
* Note that if an error occurs in single-call mode (return value is not
* XZ_STREAM_END), b->in_pos and b->out_pos are not modified and the
* contents of the output buffer from b->out[b->out_pos] onward are
* undefined. This is true even after XZ_BUF_ERROR, because with some filter
* chains, there may be a second pass over the output buffer, and this pass
* cannot be properly done if the output buffer is truncated. Thus, you
* cannot give the single-call decoder a too small buffer and then expect to
* get that amount valid data from the beginning of the stream. You must use
* the multi-call decoder if you don't want to uncompress the whole stream.
*/
XZ_EXTERN enum xz_ret xz_dec_run(struct xz_dec *s, struct xz_buf *b);
/**
* xz_dec_reset() - Reset an already allocated decoder state
* @s: Decoder state allocated using xz_dec_init()
*
* This function can be used to reset the multi-call decoder state without
* freeing and reallocating memory with xz_dec_end() and xz_dec_init().
*
* In single-call mode, xz_dec_reset() is always called in the beginning of
* xz_dec_run(). Thus, explicit call to xz_dec_reset() is useful only in
* multi-call mode.
*/
XZ_EXTERN void xz_dec_reset(struct xz_dec *s);
/**
* xz_dec_end() - Free the memory allocated for the decoder state
* @s: Decoder state allocated using xz_dec_init(). If s is NULL,
* this function does nothing.
*/
XZ_EXTERN void xz_dec_end(struct xz_dec *s);
/*
* Standalone build (userspace build or in-kernel build for boot time use)
* needs a CRC32 implementation. For normal in-kernel use, kernel's own
* CRC32 module is used instead, and users of this module don't need to
* care about the functions below.
*/
#ifndef XZ_INTERNAL_CRC32
# ifdef __KERNEL__
# define XZ_INTERNAL_CRC32 0
# else
# define XZ_INTERNAL_CRC32 1
# endif
#endif
/*
* If CRC64 support has been enabled with XZ_USE_CRC64, a CRC64
* implementation is needed too.
*/
#ifndef XZ_USE_CRC64
# undef XZ_INTERNAL_CRC64
# define XZ_INTERNAL_CRC64 0
#endif
#ifndef XZ_INTERNAL_CRC64
# ifdef __KERNEL__
# error Using CRC64 in the kernel has not been implemented.
# else
# define XZ_INTERNAL_CRC64 1
# endif
#endif
#if XZ_INTERNAL_CRC32
/*
* This must be called before any other xz_* function to initialize
* the CRC32 lookup table.
*/
XZ_EXTERN void xz_crc32_init(void);
/*
* Update CRC32 value using the polynomial from IEEE-802.3. To start a new
* calculation, the third argument must be zero. To continue the calculation,
* the previously returned value is passed as the third argument.
*/
XZ_EXTERN uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc);
#endif
#if XZ_INTERNAL_CRC64
/*
* This must be called before any other xz_* function (except xz_crc32_init())
* to initialize the CRC64 lookup table.
*/
XZ_EXTERN void xz_crc64_init(void);
/*
* Update CRC64 value using the polynomial from ECMA-182. To start a new
* calculation, the third argument must be zero. To continue the calculation,
* the previously returned value is passed as the third argument.
*/
XZ_EXTERN uint64_t xz_crc64(const uint8_t *buf, size_t size, uint64_t crc);
#endif
#ifdef __cplusplus
}
#endif
#endif

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@ -0,0 +1,124 @@
/*
* Private includes and definitions for userspace use of XZ Embedded
*
* Author: Lasse Collin <lasse.collin@tukaani.org>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#ifndef XZ_CONFIG_H
#define XZ_CONFIG_H
/* Uncomment to enable CRC64 support. */
/* #define XZ_USE_CRC64 */
/* Uncomment as needed to enable BCJ filter decoders. */
/* #define XZ_DEC_X86 */
/* #define XZ_DEC_POWERPC */
/* #define XZ_DEC_IA64 */
/* #define XZ_DEC_ARM */
/* #define XZ_DEC_ARMTHUMB */
/* #define XZ_DEC_SPARC */
/*
* MSVC doesn't support modern C but XZ Embedded is mostly C89
* so these are enough.
*/
#ifdef _MSC_VER
typedef unsigned char bool;
# define true 1
# define false 0
# define inline __inline
#else
# include <stdbool.h>
#endif
#include <stdlib.h>
#include <string.h>
#include "xz.h"
#define kmalloc(size, flags) malloc(size)
#define kfree(ptr) free(ptr)
#define vmalloc(size) malloc(size)
#define vfree(ptr) free(ptr)
#define memeq(a, b, size) (memcmp(a, b, size) == 0)
#define memzero(buf, size) memset(buf, 0, size)
#ifndef min
# define min(x, y) ((x) < (y) ? (x) : (y))
#endif
#define min_t(type, x, y) min(x, y)
/*
* Some functions have been marked with __always_inline to keep the
* performance reasonable even when the compiler is optimizing for
* small code size. You may be able to save a few bytes by #defining
* __always_inline to plain inline, but don't complain if the code
* becomes slow.
*
* NOTE: System headers on GNU/Linux may #define this macro already,
* so if you want to change it, you need to #undef it first.
*/
#ifndef __always_inline
# ifdef __GNUC__
# define __always_inline \
inline __attribute__((__always_inline__))
# else
# define __always_inline inline
# endif
#endif
/* Inline functions to access unaligned unsigned 32-bit integers */
#ifndef get_unaligned_le32
static inline uint32_t get_unaligned_le32(const uint8_t *buf)
{
return (uint32_t)buf[0]
| ((uint32_t)buf[1] << 8)
| ((uint32_t)buf[2] << 16)
| ((uint32_t)buf[3] << 24);
}
#endif
#ifndef get_unaligned_be32
static inline uint32_t get_unaligned_be32(const uint8_t *buf)
{
return (uint32_t)(buf[0] << 24)
| ((uint32_t)buf[1] << 16)
| ((uint32_t)buf[2] << 8)
| (uint32_t)buf[3];
}
#endif
#ifndef put_unaligned_le32
static inline void put_unaligned_le32(uint32_t val, uint8_t *buf)
{
buf[0] = (uint8_t)val;
buf[1] = (uint8_t)(val >> 8);
buf[2] = (uint8_t)(val >> 16);
buf[3] = (uint8_t)(val >> 24);
}
#endif
#ifndef put_unaligned_be32
static inline void put_unaligned_be32(uint32_t val, uint8_t *buf)
{
buf[0] = (uint8_t)(val >> 24);
buf[1] = (uint8_t)(val >> 16);
buf[2] = (uint8_t)(val >> 8);
buf[3] = (uint8_t)val;
}
#endif
/*
* Use get_unaligned_le32() also for aligned access for simplicity. On
* little endian systems, #define get_le32(ptr) (*(const uint32_t *)(ptr))
* could save a few bytes in code size.
*/
#ifndef get_le32
# define get_le32 get_unaligned_le32
#endif
#endif

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@ -0,0 +1,59 @@
/*
* CRC32 using the polynomial from IEEE-802.3
*
* Authors: Lasse Collin <lasse.collin@tukaani.org>
* Igor Pavlov <http://7-zip.org/>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
/*
* This is not the fastest implementation, but it is pretty compact.
* The fastest versions of xz_crc32() on modern CPUs without hardware
* accelerated CRC instruction are 3-5 times as fast as this version,
* but they are bigger and use more memory for the lookup table.
*/
#include "xz_private.h"
/*
* STATIC_RW_DATA is used in the pre-boot environment on some architectures.
* See <linux/decompress/mm.h> for details.
*/
#ifndef STATIC_RW_DATA
# define STATIC_RW_DATA static
#endif
STATIC_RW_DATA uint32_t xz_crc32_table[256];
XZ_EXTERN void xz_crc32_init(void)
{
const uint32_t poly = 0xEDB88320;
uint32_t i;
uint32_t j;
uint32_t r;
for (i = 0; i < 256; ++i) {
r = i;
for (j = 0; j < 8; ++j)
r = (r >> 1) ^ (poly & ~((r & 1) - 1));
xz_crc32_table[i] = r;
}
return;
}
XZ_EXTERN uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
{
crc = ~crc;
while (size != 0) {
crc = xz_crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
--size;
}
return ~crc;
}

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@ -0,0 +1,847 @@
/*
* .xz Stream decoder
*
* Author: Lasse Collin <lasse.collin@tukaani.org>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#include "xz_private.h"
#include "xz_stream.h"
#ifdef XZ_USE_CRC64
# define IS_CRC64(check_type) ((check_type) == XZ_CHECK_CRC64)
#else
# define IS_CRC64(check_type) false
#endif
/* Hash used to validate the Index field */
struct xz_dec_hash {
vli_type unpadded;
vli_type uncompressed;
uint32_t crc32;
};
struct xz_dec {
/* Position in dec_main() */
enum {
SEQ_STREAM_HEADER,
SEQ_BLOCK_START,
SEQ_BLOCK_HEADER,
SEQ_BLOCK_UNCOMPRESS,
SEQ_BLOCK_PADDING,
SEQ_BLOCK_CHECK,
SEQ_INDEX,
SEQ_INDEX_PADDING,
SEQ_INDEX_CRC32,
SEQ_STREAM_FOOTER
} sequence;
/* Position in variable-length integers and Check fields */
uint32_t pos;
/* Variable-length integer decoded by dec_vli() */
vli_type vli;
/* Saved in_pos and out_pos */
size_t in_start;
size_t out_start;
#ifdef XZ_USE_CRC64
/* CRC32 or CRC64 value in Block or CRC32 value in Index */
uint64_t crc;
#else
/* CRC32 value in Block or Index */
uint32_t crc;
#endif
/* Type of the integrity check calculated from uncompressed data */
enum xz_check check_type;
/* Operation mode */
enum xz_mode mode;
/*
* True if the next call to xz_dec_run() is allowed to return
* XZ_BUF_ERROR.
*/
bool allow_buf_error;
/* Information stored in Block Header */
struct {
/*
* Value stored in the Compressed Size field, or
* VLI_UNKNOWN if Compressed Size is not present.
*/
vli_type compressed;
/*
* Value stored in the Uncompressed Size field, or
* VLI_UNKNOWN if Uncompressed Size is not present.
*/
vli_type uncompressed;
/* Size of the Block Header field */
uint32_t size;
} block_header;
/* Information collected when decoding Blocks */
struct {
/* Observed compressed size of the current Block */
vli_type compressed;
/* Observed uncompressed size of the current Block */
vli_type uncompressed;
/* Number of Blocks decoded so far */
vli_type count;
/*
* Hash calculated from the Block sizes. This is used to
* validate the Index field.
*/
struct xz_dec_hash hash;
} block;
/* Variables needed when verifying the Index field */
struct {
/* Position in dec_index() */
enum {
SEQ_INDEX_COUNT,
SEQ_INDEX_UNPADDED,
SEQ_INDEX_UNCOMPRESSED
} sequence;
/* Size of the Index in bytes */
vli_type size;
/* Number of Records (matches block.count in valid files) */
vli_type count;
/*
* Hash calculated from the Records (matches block.hash in
* valid files).
*/
struct xz_dec_hash hash;
} index;
/*
* Temporary buffer needed to hold Stream Header, Block Header,
* and Stream Footer. The Block Header is the biggest (1 KiB)
* so we reserve space according to that. buf[] has to be aligned
* to a multiple of four bytes; the size_t variables before it
* should guarantee this.
*/
struct {
size_t pos;
size_t size;
uint8_t buf[1024];
} temp;
struct xz_dec_lzma2 *lzma2;
#ifdef XZ_DEC_BCJ
struct xz_dec_bcj *bcj;
bool bcj_active;
#endif
};
#ifdef XZ_DEC_ANY_CHECK
/* Sizes of the Check field with different Check IDs */
static const uint8_t check_sizes[16] = {
0,
4, 4, 4,
8, 8, 8,
16, 16, 16,
32, 32, 32,
64, 64, 64
};
#endif
/*
* Fill s->temp by copying data starting from b->in[b->in_pos]. Caller
* must have set s->temp.pos to indicate how much data we are supposed
* to copy into s->temp.buf. Return true once s->temp.pos has reached
* s->temp.size.
*/
static bool fill_temp(struct xz_dec *s, struct xz_buf *b)
{
size_t copy_size = min_t(size_t,
b->in_size - b->in_pos, s->temp.size - s->temp.pos);
memcpy(s->temp.buf + s->temp.pos, b->in + b->in_pos, copy_size);
b->in_pos += copy_size;
s->temp.pos += copy_size;
if (s->temp.pos == s->temp.size) {
s->temp.pos = 0;
return true;
}
return false;
}
/* Decode a variable-length integer (little-endian base-128 encoding) */
static enum xz_ret dec_vli(struct xz_dec *s, const uint8_t *in,
size_t *in_pos, size_t in_size)
{
uint8_t byte;
if (s->pos == 0)
s->vli = 0;
while (*in_pos < in_size) {
byte = in[*in_pos];
++*in_pos;
s->vli |= (vli_type)(byte & 0x7F) << s->pos;
if ((byte & 0x80) == 0) {
/* Don't allow non-minimal encodings. */
if (byte == 0 && s->pos != 0)
return XZ_DATA_ERROR;
s->pos = 0;
return XZ_STREAM_END;
}
s->pos += 7;
if (s->pos == 7 * VLI_BYTES_MAX)
return XZ_DATA_ERROR;
}
return XZ_OK;
}
/*
* Decode the Compressed Data field from a Block. Update and validate
* the observed compressed and uncompressed sizes of the Block so that
* they don't exceed the values possibly stored in the Block Header
* (validation assumes that no integer overflow occurs, since vli_type
* is normally uint64_t). Update the CRC32 or CRC64 value if presence of
* the CRC32 or CRC64 field was indicated in Stream Header.
*
* Once the decoding is finished, validate that the observed sizes match
* the sizes possibly stored in the Block Header. Update the hash and
* Block count, which are later used to validate the Index field.
*/
static enum xz_ret dec_block(struct xz_dec *s, struct xz_buf *b)
{
enum xz_ret ret;
s->in_start = b->in_pos;
s->out_start = b->out_pos;
#ifdef XZ_DEC_BCJ
if (s->bcj_active)
ret = xz_dec_bcj_run(s->bcj, s->lzma2, b);
else
#endif
ret = xz_dec_lzma2_run(s->lzma2, b);
s->block.compressed += b->in_pos - s->in_start;
s->block.uncompressed += b->out_pos - s->out_start;
/*
* There is no need to separately check for VLI_UNKNOWN, since
* the observed sizes are always smaller than VLI_UNKNOWN.
*/
if (s->block.compressed > s->block_header.compressed
|| s->block.uncompressed
> s->block_header.uncompressed)
return XZ_DATA_ERROR;
if (s->check_type == XZ_CHECK_CRC32)
s->crc = xz_crc32(b->out + s->out_start,
b->out_pos - s->out_start, s->crc);
#ifdef XZ_USE_CRC64
else if (s->check_type == XZ_CHECK_CRC64)
s->crc = xz_crc64(b->out + s->out_start,
b->out_pos - s->out_start, s->crc);
#endif
if (ret == XZ_STREAM_END) {
if (s->block_header.compressed != VLI_UNKNOWN
&& s->block_header.compressed
!= s->block.compressed)
return XZ_DATA_ERROR;
if (s->block_header.uncompressed != VLI_UNKNOWN
&& s->block_header.uncompressed
!= s->block.uncompressed)
return XZ_DATA_ERROR;
s->block.hash.unpadded += s->block_header.size
+ s->block.compressed;
#ifdef XZ_DEC_ANY_CHECK
s->block.hash.unpadded += check_sizes[s->check_type];
#else
if (s->check_type == XZ_CHECK_CRC32)
s->block.hash.unpadded += 4;
else if (IS_CRC64(s->check_type))
s->block.hash.unpadded += 8;
#endif
s->block.hash.uncompressed += s->block.uncompressed;
s->block.hash.crc32 = xz_crc32(
(const uint8_t *)&s->block.hash,
sizeof(s->block.hash), s->block.hash.crc32);
++s->block.count;
}
return ret;
}
/* Update the Index size and the CRC32 value. */
static void index_update(struct xz_dec *s, const struct xz_buf *b)
{
size_t in_used = b->in_pos - s->in_start;
s->index.size += in_used;
s->crc = xz_crc32(b->in + s->in_start, in_used, s->crc);
}
/*
* Decode the Number of Records, Unpadded Size, and Uncompressed Size
* fields from the Index field. That is, Index Padding and CRC32 are not
* decoded by this function.
*
* This can return XZ_OK (more input needed), XZ_STREAM_END (everything
* successfully decoded), or XZ_DATA_ERROR (input is corrupt).
*/
static enum xz_ret dec_index(struct xz_dec *s, struct xz_buf *b)
{
enum xz_ret ret;
do {
ret = dec_vli(s, b->in, &b->in_pos, b->in_size);
if (ret != XZ_STREAM_END) {
index_update(s, b);
return ret;
}
switch (s->index.sequence) {
case SEQ_INDEX_COUNT:
s->index.count = s->vli;
/*
* Validate that the Number of Records field
* indicates the same number of Records as
* there were Blocks in the Stream.
*/
if (s->index.count != s->block.count)
return XZ_DATA_ERROR;
s->index.sequence = SEQ_INDEX_UNPADDED;
break;
case SEQ_INDEX_UNPADDED:
s->index.hash.unpadded += s->vli;
s->index.sequence = SEQ_INDEX_UNCOMPRESSED;
break;
case SEQ_INDEX_UNCOMPRESSED:
s->index.hash.uncompressed += s->vli;
s->index.hash.crc32 = xz_crc32(
(const uint8_t *)&s->index.hash,
sizeof(s->index.hash),
s->index.hash.crc32);
--s->index.count;
s->index.sequence = SEQ_INDEX_UNPADDED;
break;
}
} while (s->index.count > 0);
return XZ_STREAM_END;
}
/*
* Validate that the next four or eight input bytes match the value
* of s->crc. s->pos must be zero when starting to validate the first byte.
* The "bits" argument allows using the same code for both CRC32 and CRC64.
*/
static enum xz_ret crc_validate(struct xz_dec *s, struct xz_buf *b,
uint32_t bits)
{
do {
if (b->in_pos == b->in_size)
return XZ_OK;
if (((s->crc >> s->pos) & 0xFF) != b->in[b->in_pos++])
return XZ_DATA_ERROR;
s->pos += 8;
} while (s->pos < bits);
s->crc = 0;
s->pos = 0;
return XZ_STREAM_END;
}
#ifdef XZ_DEC_ANY_CHECK
/*
* Skip over the Check field when the Check ID is not supported.
* Returns true once the whole Check field has been skipped over.
*/
static bool check_skip(struct xz_dec *s, struct xz_buf *b)
{
while (s->pos < check_sizes[s->check_type]) {
if (b->in_pos == b->in_size)
return false;
++b->in_pos;
++s->pos;
}
s->pos = 0;
return true;
}
#endif
/* Decode the Stream Header field (the first 12 bytes of the .xz Stream). */
static enum xz_ret dec_stream_header(struct xz_dec *s)
{
if (!memeq(s->temp.buf, HEADER_MAGIC, HEADER_MAGIC_SIZE))
return XZ_FORMAT_ERROR;
if (xz_crc32(s->temp.buf + HEADER_MAGIC_SIZE, 2, 0)
!= get_le32(s->temp.buf + HEADER_MAGIC_SIZE + 2))
return XZ_DATA_ERROR;
if (s->temp.buf[HEADER_MAGIC_SIZE] != 0)
return XZ_OPTIONS_ERROR;
/*
* Of integrity checks, we support none (Check ID = 0),
* CRC32 (Check ID = 1), and optionally CRC64 (Check ID = 4).
* However, if XZ_DEC_ANY_CHECK is defined, we will accept other
* check types too, but then the check won't be verified and
* a warning (XZ_UNSUPPORTED_CHECK) will be given.
*/
s->check_type = s->temp.buf[HEADER_MAGIC_SIZE + 1];
#ifdef XZ_DEC_ANY_CHECK
if (s->check_type > XZ_CHECK_MAX)
return XZ_OPTIONS_ERROR;
if (s->check_type > XZ_CHECK_CRC32 && !IS_CRC64(s->check_type))
return XZ_UNSUPPORTED_CHECK;
#else
if (s->check_type > XZ_CHECK_CRC32 && !IS_CRC64(s->check_type))
return XZ_OPTIONS_ERROR;
#endif
return XZ_OK;
}
/* Decode the Stream Footer field (the last 12 bytes of the .xz Stream) */
static enum xz_ret dec_stream_footer(struct xz_dec *s)
{
if (!memeq(s->temp.buf + 10, FOOTER_MAGIC, FOOTER_MAGIC_SIZE))
return XZ_DATA_ERROR;
if (xz_crc32(s->temp.buf + 4, 6, 0) != get_le32(s->temp.buf))
return XZ_DATA_ERROR;
/*
* Validate Backward Size. Note that we never added the size of the
* Index CRC32 field to s->index.size, thus we use s->index.size / 4
* instead of s->index.size / 4 - 1.
*/
if ((s->index.size >> 2) != get_le32(s->temp.buf + 4))
return XZ_DATA_ERROR;
if (s->temp.buf[8] != 0 || s->temp.buf[9] != s->check_type)
return XZ_DATA_ERROR;
/*
* Use XZ_STREAM_END instead of XZ_OK to be more convenient
* for the caller.
*/
return XZ_STREAM_END;
}
/* Decode the Block Header and initialize the filter chain. */
static enum xz_ret dec_block_header(struct xz_dec *s)
{
enum xz_ret ret;
/*
* Validate the CRC32. We know that the temp buffer is at least
* eight bytes so this is safe.
*/
s->temp.size -= 4;
if (xz_crc32(s->temp.buf, s->temp.size, 0)
!= get_le32(s->temp.buf + s->temp.size))
return XZ_DATA_ERROR;
s->temp.pos = 2;
/*
* Catch unsupported Block Flags. We support only one or two filters
* in the chain, so we catch that with the same test.
*/
#ifdef XZ_DEC_BCJ
if (s->temp.buf[1] & 0x3E)
#else
if (s->temp.buf[1] & 0x3F)
#endif
return XZ_OPTIONS_ERROR;
/* Compressed Size */
if (s->temp.buf[1] & 0x40) {
if (dec_vli(s, s->temp.buf, &s->temp.pos, s->temp.size)
!= XZ_STREAM_END)
return XZ_DATA_ERROR;
s->block_header.compressed = s->vli;
} else {
s->block_header.compressed = VLI_UNKNOWN;
}
/* Uncompressed Size */
if (s->temp.buf[1] & 0x80) {
if (dec_vli(s, s->temp.buf, &s->temp.pos, s->temp.size)
!= XZ_STREAM_END)
return XZ_DATA_ERROR;
s->block_header.uncompressed = s->vli;
} else {
s->block_header.uncompressed = VLI_UNKNOWN;
}
#ifdef XZ_DEC_BCJ
/* If there are two filters, the first one must be a BCJ filter. */
s->bcj_active = s->temp.buf[1] & 0x01;
if (s->bcj_active) {
if (s->temp.size - s->temp.pos < 2)
return XZ_OPTIONS_ERROR;
ret = xz_dec_bcj_reset(s->bcj, s->temp.buf[s->temp.pos++]);
if (ret != XZ_OK)
return ret;
/*
* We don't support custom start offset,
* so Size of Properties must be zero.
*/
if (s->temp.buf[s->temp.pos++] != 0x00)
return XZ_OPTIONS_ERROR;
}
#endif
/* Valid Filter Flags always take at least two bytes. */
if (s->temp.size - s->temp.pos < 2)
return XZ_DATA_ERROR;
/* Filter ID = LZMA2 */
if (s->temp.buf[s->temp.pos++] != 0x21)
return XZ_OPTIONS_ERROR;
/* Size of Properties = 1-byte Filter Properties */
if (s->temp.buf[s->temp.pos++] != 0x01)
return XZ_OPTIONS_ERROR;
/* Filter Properties contains LZMA2 dictionary size. */
if (s->temp.size - s->temp.pos < 1)
return XZ_DATA_ERROR;
ret = xz_dec_lzma2_reset(s->lzma2, s->temp.buf[s->temp.pos++]);
if (ret != XZ_OK)
return ret;
/* The rest must be Header Padding. */
while (s->temp.pos < s->temp.size)
if (s->temp.buf[s->temp.pos++] != 0x00)
return XZ_OPTIONS_ERROR;
s->temp.pos = 0;
s->block.compressed = 0;
s->block.uncompressed = 0;
return XZ_OK;
}
static enum xz_ret dec_main(struct xz_dec *s, struct xz_buf *b)
{
enum xz_ret ret;
/*
* Store the start position for the case when we are in the middle
* of the Index field.
*/
s->in_start = b->in_pos;
while (true) {
switch (s->sequence) {
case SEQ_STREAM_HEADER:
/*
* Stream Header is copied to s->temp, and then
* decoded from there. This way if the caller
* gives us only little input at a time, we can
* still keep the Stream Header decoding code
* simple. Similar approach is used in many places
* in this file.
*/
if (!fill_temp(s, b))
return XZ_OK;
/*
* If dec_stream_header() returns
* XZ_UNSUPPORTED_CHECK, it is still possible
* to continue decoding if working in multi-call
* mode. Thus, update s->sequence before calling
* dec_stream_header().
*/
s->sequence = SEQ_BLOCK_START;
ret = dec_stream_header(s);
if (ret != XZ_OK)
return ret;
case SEQ_BLOCK_START:
/* We need one byte of input to continue. */
if (b->in_pos == b->in_size)
return XZ_OK;
/* See if this is the beginning of the Index field. */
if (b->in[b->in_pos] == 0) {
s->in_start = b->in_pos++;
s->sequence = SEQ_INDEX;
break;
}
/*
* Calculate the size of the Block Header and
* prepare to decode it.
*/
s->block_header.size
= ((uint32_t)b->in[b->in_pos] + 1) * 4;
s->temp.size = s->block_header.size;
s->temp.pos = 0;
s->sequence = SEQ_BLOCK_HEADER;
case SEQ_BLOCK_HEADER:
if (!fill_temp(s, b))
return XZ_OK;
ret = dec_block_header(s);
if (ret != XZ_OK)
return ret;
s->sequence = SEQ_BLOCK_UNCOMPRESS;
case SEQ_BLOCK_UNCOMPRESS:
ret = dec_block(s, b);
if (ret != XZ_STREAM_END)
return ret;
s->sequence = SEQ_BLOCK_PADDING;
case SEQ_BLOCK_PADDING:
/*
* Size of Compressed Data + Block Padding
* must be a multiple of four. We don't need
* s->block.compressed for anything else
* anymore, so we use it here to test the size
* of the Block Padding field.
*/
while (s->block.compressed & 3) {
if (b->in_pos == b->in_size)
return XZ_OK;
if (b->in[b->in_pos++] != 0)
return XZ_DATA_ERROR;
++s->block.compressed;
}
s->sequence = SEQ_BLOCK_CHECK;
case SEQ_BLOCK_CHECK:
if (s->check_type == XZ_CHECK_CRC32) {
ret = crc_validate(s, b, 32);
if (ret != XZ_STREAM_END)
return ret;
}
else if (IS_CRC64(s->check_type)) {
ret = crc_validate(s, b, 64);
if (ret != XZ_STREAM_END)
return ret;
}
#ifdef XZ_DEC_ANY_CHECK
else if (!check_skip(s, b)) {
return XZ_OK;
}
#endif
s->sequence = SEQ_BLOCK_START;
break;
case SEQ_INDEX:
ret = dec_index(s, b);
if (ret != XZ_STREAM_END)
return ret;
s->sequence = SEQ_INDEX_PADDING;
case SEQ_INDEX_PADDING:
while ((s->index.size + (b->in_pos - s->in_start))
& 3) {
if (b->in_pos == b->in_size) {
index_update(s, b);
return XZ_OK;
}
if (b->in[b->in_pos++] != 0)
return XZ_DATA_ERROR;
}
/* Finish the CRC32 value and Index size. */
index_update(s, b);
/* Compare the hashes to validate the Index field. */
if (!memeq(&s->block.hash, &s->index.hash,
sizeof(s->block.hash)))
return XZ_DATA_ERROR;
s->sequence = SEQ_INDEX_CRC32;
case SEQ_INDEX_CRC32:
ret = crc_validate(s, b, 32);
if (ret != XZ_STREAM_END)
return ret;
s->temp.size = STREAM_HEADER_SIZE;
s->sequence = SEQ_STREAM_FOOTER;
case SEQ_STREAM_FOOTER:
if (!fill_temp(s, b))
return XZ_OK;
return dec_stream_footer(s);
}
}
/* Never reached */
}
/*
* xz_dec_run() is a wrapper for dec_main() to handle some special cases in
* multi-call and single-call decoding.
*
* In multi-call mode, we must return XZ_BUF_ERROR when it seems clear that we
* are not going to make any progress anymore. This is to prevent the caller
* from calling us infinitely when the input file is truncated or otherwise
* corrupt. Since zlib-style API allows that the caller fills the input buffer
* only when the decoder doesn't produce any new output, we have to be careful
* to avoid returning XZ_BUF_ERROR too easily: XZ_BUF_ERROR is returned only
* after the second consecutive call to xz_dec_run() that makes no progress.
*
* In single-call mode, if we couldn't decode everything and no error
* occurred, either the input is truncated or the output buffer is too small.
* Since we know that the last input byte never produces any output, we know
* that if all the input was consumed and decoding wasn't finished, the file
* must be corrupt. Otherwise the output buffer has to be too small or the
* file is corrupt in a way that decoding it produces too big output.
*
* If single-call decoding fails, we reset b->in_pos and b->out_pos back to
* their original values. This is because with some filter chains there won't
* be any valid uncompressed data in the output buffer unless the decoding
* actually succeeds (that's the price to pay of using the output buffer as
* the workspace).
*/
XZ_EXTERN enum xz_ret xz_dec_run(struct xz_dec *s, struct xz_buf *b)
{
size_t in_start;
size_t out_start;
enum xz_ret ret;
if (DEC_IS_SINGLE(s->mode))
xz_dec_reset(s);
in_start = b->in_pos;
out_start = b->out_pos;
ret = dec_main(s, b);
if (DEC_IS_SINGLE(s->mode)) {
if (ret == XZ_OK)
ret = b->in_pos == b->in_size
? XZ_DATA_ERROR : XZ_BUF_ERROR;
if (ret != XZ_STREAM_END) {
b->in_pos = in_start;
b->out_pos = out_start;
}
} else if (ret == XZ_OK && in_start == b->in_pos
&& out_start == b->out_pos) {
if (s->allow_buf_error)
ret = XZ_BUF_ERROR;
s->allow_buf_error = true;
} else {
s->allow_buf_error = false;
}
return ret;
}
XZ_EXTERN struct xz_dec *xz_dec_init(enum xz_mode mode, uint32_t dict_max)
{
struct xz_dec *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s == NULL)
return NULL;
s->mode = mode;
#ifdef XZ_DEC_BCJ
s->bcj = xz_dec_bcj_create(DEC_IS_SINGLE(mode));
if (s->bcj == NULL)
goto error_bcj;
#endif
s->lzma2 = xz_dec_lzma2_create(mode, dict_max);
if (s->lzma2 == NULL)
goto error_lzma2;
xz_dec_reset(s);
return s;
error_lzma2:
#ifdef XZ_DEC_BCJ
xz_dec_bcj_end(s->bcj);
error_bcj:
#endif
kfree(s);
return NULL;
}
XZ_EXTERN void xz_dec_reset(struct xz_dec *s)
{
s->sequence = SEQ_STREAM_HEADER;
s->allow_buf_error = false;
s->pos = 0;
s->crc = 0;
memzero(&s->block, sizeof(s->block));
memzero(&s->index, sizeof(s->index));
s->temp.pos = 0;
s->temp.size = STREAM_HEADER_SIZE;
}
XZ_EXTERN void xz_dec_end(struct xz_dec *s)
{
if (s != NULL) {
xz_dec_lzma2_end(s->lzma2);
#ifdef XZ_DEC_BCJ
xz_dec_bcj_end(s->bcj);
#endif
kfree(s);
}
}

View File

@ -0,0 +1,204 @@
/*
* LZMA2 definitions
*
* Authors: Lasse Collin <lasse.collin@tukaani.org>
* Igor Pavlov <http://7-zip.org/>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#ifndef XZ_LZMA2_H
#define XZ_LZMA2_H
/* Range coder constants */
#define RC_SHIFT_BITS 8
#define RC_TOP_BITS 24
#define RC_TOP_VALUE (1 << RC_TOP_BITS)
#define RC_BIT_MODEL_TOTAL_BITS 11
#define RC_BIT_MODEL_TOTAL (1 << RC_BIT_MODEL_TOTAL_BITS)
#define RC_MOVE_BITS 5
/*
* Maximum number of position states. A position state is the lowest pb
* number of bits of the current uncompressed offset. In some places there
* are different sets of probabilities for different position states.
*/
#define POS_STATES_MAX (1 << 4)
/*
* This enum is used to track which LZMA symbols have occurred most recently
* and in which order. This information is used to predict the next symbol.
*
* Symbols:
* - Literal: One 8-bit byte
* - Match: Repeat a chunk of data at some distance
* - Long repeat: Multi-byte match at a recently seen distance
* - Short repeat: One-byte repeat at a recently seen distance
*
* The symbol names are in from STATE_oldest_older_previous. REP means
* either short or long repeated match, and NONLIT means any non-literal.
*/
enum lzma_state {
STATE_LIT_LIT,
STATE_MATCH_LIT_LIT,
STATE_REP_LIT_LIT,
STATE_SHORTREP_LIT_LIT,
STATE_MATCH_LIT,
STATE_REP_LIT,
STATE_SHORTREP_LIT,
STATE_LIT_MATCH,
STATE_LIT_LONGREP,
STATE_LIT_SHORTREP,
STATE_NONLIT_MATCH,
STATE_NONLIT_REP
};
/* Total number of states */
#define STATES 12
/* The lowest 7 states indicate that the previous state was a literal. */
#define LIT_STATES 7
/* Indicate that the latest symbol was a literal. */
static inline void lzma_state_literal(enum lzma_state *state)
{
if (*state <= STATE_SHORTREP_LIT_LIT)
*state = STATE_LIT_LIT;
else if (*state <= STATE_LIT_SHORTREP)
*state -= 3;
else
*state -= 6;
}
/* Indicate that the latest symbol was a match. */
static inline void lzma_state_match(enum lzma_state *state)
{
*state = *state < LIT_STATES ? STATE_LIT_MATCH : STATE_NONLIT_MATCH;
}
/* Indicate that the latest state was a long repeated match. */
static inline void lzma_state_long_rep(enum lzma_state *state)
{
*state = *state < LIT_STATES ? STATE_LIT_LONGREP : STATE_NONLIT_REP;
}
/* Indicate that the latest symbol was a short match. */
static inline void lzma_state_short_rep(enum lzma_state *state)
{
*state = *state < LIT_STATES ? STATE_LIT_SHORTREP : STATE_NONLIT_REP;
}
/* Test if the previous symbol was a literal. */
static inline bool lzma_state_is_literal(enum lzma_state state)
{
return state < LIT_STATES;
}
/* Each literal coder is divided in three sections:
* - 0x001-0x0FF: Without match byte
* - 0x101-0x1FF: With match byte; match bit is 0
* - 0x201-0x2FF: With match byte; match bit is 1
*
* Match byte is used when the previous LZMA symbol was something else than
* a literal (that is, it was some kind of match).
*/
#define LITERAL_CODER_SIZE 0x300
/* Maximum number of literal coders */
#define LITERAL_CODERS_MAX (1 << 4)
/* Minimum length of a match is two bytes. */
#define MATCH_LEN_MIN 2
/* Match length is encoded with 4, 5, or 10 bits.
*
* Length Bits
* 2-9 4 = Choice=0 + 3 bits
* 10-17 5 = Choice=1 + Choice2=0 + 3 bits
* 18-273 10 = Choice=1 + Choice2=1 + 8 bits
*/
#define LEN_LOW_BITS 3
#define LEN_LOW_SYMBOLS (1 << LEN_LOW_BITS)
#define LEN_MID_BITS 3
#define LEN_MID_SYMBOLS (1 << LEN_MID_BITS)
#define LEN_HIGH_BITS 8
#define LEN_HIGH_SYMBOLS (1 << LEN_HIGH_BITS)
#define LEN_SYMBOLS (LEN_LOW_SYMBOLS + LEN_MID_SYMBOLS + LEN_HIGH_SYMBOLS)
/*
* Maximum length of a match is 273 which is a result of the encoding
* described above.
*/
#define MATCH_LEN_MAX (MATCH_LEN_MIN + LEN_SYMBOLS - 1)
/*
* Different sets of probabilities are used for match distances that have
* very short match length: Lengths of 2, 3, and 4 bytes have a separate
* set of probabilities for each length. The matches with longer length
* use a shared set of probabilities.
*/
#define DIST_STATES 4
/*
* Get the index of the appropriate probability array for decoding
* the distance slot.
*/
static inline uint32_t lzma_get_dist_state(uint32_t len)
{
return len < DIST_STATES + MATCH_LEN_MIN
? len - MATCH_LEN_MIN : DIST_STATES - 1;
}
/*
* The highest two bits of a 32-bit match distance are encoded using six bits.
* This six-bit value is called a distance slot. This way encoding a 32-bit
* value takes 6-36 bits, larger values taking more bits.
*/
#define DIST_SLOT_BITS 6
#define DIST_SLOTS (1 << DIST_SLOT_BITS)
/* Match distances up to 127 are fully encoded using probabilities. Since
* the highest two bits (distance slot) are always encoded using six bits,
* the distances 0-3 don't need any additional bits to encode, since the
* distance slot itself is the same as the actual distance. DIST_MODEL_START
* indicates the first distance slot where at least one additional bit is
* needed.
*/
#define DIST_MODEL_START 4
/*
* Match distances greater than 127 are encoded in three pieces:
* - distance slot: the highest two bits
* - direct bits: 2-26 bits below the highest two bits
* - alignment bits: four lowest bits
*
* Direct bits don't use any probabilities.
*
* The distance slot value of 14 is for distances 128-191.
*/
#define DIST_MODEL_END 14
/* Distance slots that indicate a distance <= 127. */
#define FULL_DISTANCES_BITS (DIST_MODEL_END / 2)
#define FULL_DISTANCES (1 << FULL_DISTANCES_BITS)
/*
* For match distances greater than 127, only the highest two bits and the
* lowest four bits (alignment) is encoded using probabilities.
*/
#define ALIGN_BITS 4
#define ALIGN_SIZE (1 << ALIGN_BITS)
#define ALIGN_MASK (ALIGN_SIZE - 1)
/* Total number of all probability variables */
#define PROBS_TOTAL (1846 + LITERAL_CODERS_MAX * LITERAL_CODER_SIZE)
/*
* LZMA remembers the four most recent match distances. Reusing these
* distances tends to take less space than re-encoding the actual
* distance value.
*/
#define REPS 4
#endif

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/*
* Private includes and definitions
*
* Author: Lasse Collin <lasse.collin@tukaani.org>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#ifndef XZ_PRIVATE_H
#define XZ_PRIVATE_H
#ifdef __KERNEL__
# include <linux/xz.h>
# include <linux/kernel.h>
# include <asm/unaligned.h>
/* XZ_PREBOOT may be defined only via decompress_unxz.c. */
# ifndef XZ_PREBOOT
# include <linux/slab.h>
# include <linux/vmalloc.h>
# include <linux/string.h>
# ifdef CONFIG_XZ_DEC_X86
# define XZ_DEC_X86
# endif
# ifdef CONFIG_XZ_DEC_POWERPC
# define XZ_DEC_POWERPC
# endif
# ifdef CONFIG_XZ_DEC_IA64
# define XZ_DEC_IA64
# endif
# ifdef CONFIG_XZ_DEC_ARM
# define XZ_DEC_ARM
# endif
# ifdef CONFIG_XZ_DEC_ARMTHUMB
# define XZ_DEC_ARMTHUMB
# endif
# ifdef CONFIG_XZ_DEC_SPARC
# define XZ_DEC_SPARC
# endif
# define memeq(a, b, size) (memcmp(a, b, size) == 0)
# define memzero(buf, size) memset(buf, 0, size)
# endif
# define get_le32(p) le32_to_cpup((const uint32_t *)(p))
#else
/*
* For userspace builds, use a separate header to define the required
* macros and functions. This makes it easier to adapt the code into
* different environments and avoids clutter in the Linux kernel tree.
*/
# include "xz_config.h"
#endif
/* If no specific decoding mode is requested, enable support for all modes. */
#if !defined(XZ_DEC_SINGLE) && !defined(XZ_DEC_PREALLOC) \
&& !defined(XZ_DEC_DYNALLOC)
# define XZ_DEC_SINGLE
# define XZ_DEC_PREALLOC
# define XZ_DEC_DYNALLOC
#endif
/*
* The DEC_IS_foo(mode) macros are used in "if" statements. If only some
* of the supported modes are enabled, these macros will evaluate to true or
* false at compile time and thus allow the compiler to omit unneeded code.
*/
#ifdef XZ_DEC_SINGLE
# define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE)
#else
# define DEC_IS_SINGLE(mode) (false)
#endif
#ifdef XZ_DEC_PREALLOC
# define DEC_IS_PREALLOC(mode) ((mode) == XZ_PREALLOC)
#else
# define DEC_IS_PREALLOC(mode) (false)
#endif
#ifdef XZ_DEC_DYNALLOC
# define DEC_IS_DYNALLOC(mode) ((mode) == XZ_DYNALLOC)
#else
# define DEC_IS_DYNALLOC(mode) (false)
#endif
#if !defined(XZ_DEC_SINGLE)
# define DEC_IS_MULTI(mode) (true)
#elif defined(XZ_DEC_PREALLOC) || defined(XZ_DEC_DYNALLOC)
# define DEC_IS_MULTI(mode) ((mode) != XZ_SINGLE)
#else
# define DEC_IS_MULTI(mode) (false)
#endif
/*
* If any of the BCJ filter decoders are wanted, define XZ_DEC_BCJ.
* XZ_DEC_BCJ is used to enable generic support for BCJ decoders.
*/
#ifndef XZ_DEC_BCJ
# if defined(XZ_DEC_X86) || defined(XZ_DEC_POWERPC) \
|| defined(XZ_DEC_IA64) || defined(XZ_DEC_ARM) \
|| defined(XZ_DEC_ARM) || defined(XZ_DEC_ARMTHUMB) \
|| defined(XZ_DEC_SPARC)
# define XZ_DEC_BCJ
# endif
#endif
/*
* Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used
* before calling xz_dec_lzma2_run().
*/
XZ_EXTERN struct xz_dec_lzma2 *xz_dec_lzma2_create(enum xz_mode mode,
uint32_t dict_max);
/*
* Decode the LZMA2 properties (one byte) and reset the decoder. Return
* XZ_OK on success, XZ_MEMLIMIT_ERROR if the preallocated dictionary is not
* big enough, and XZ_OPTIONS_ERROR if props indicates something that this
* decoder doesn't support.
*/
XZ_EXTERN enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s,
uint8_t props);
/* Decode raw LZMA2 stream from b->in to b->out. */
XZ_EXTERN enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s,
struct xz_buf *b);
/* Free the memory allocated for the LZMA2 decoder. */
XZ_EXTERN void xz_dec_lzma2_end(struct xz_dec_lzma2 *s);
#ifdef XZ_DEC_BCJ
/*
* Allocate memory for BCJ decoders. xz_dec_bcj_reset() must be used before
* calling xz_dec_bcj_run().
*/
XZ_EXTERN struct xz_dec_bcj *xz_dec_bcj_create(bool single_call);
/*
* Decode the Filter ID of a BCJ filter. This implementation doesn't
* support custom start offsets, so no decoding of Filter Properties
* is needed. Returns XZ_OK if the given Filter ID is supported.
* Otherwise XZ_OPTIONS_ERROR is returned.
*/
XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id);
/*
* Decode raw BCJ + LZMA2 stream. This must be used only if there actually is
* a BCJ filter in the chain. If the chain has only LZMA2, xz_dec_lzma2_run()
* must be called directly.
*/
XZ_EXTERN enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s,
struct xz_dec_lzma2 *lzma2,
struct xz_buf *b);
/* Free the memory allocated for the BCJ filters. */
#define xz_dec_bcj_end(s) kfree(s)
#endif
#endif

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/*
* Definitions for handling the .xz file format
*
* Author: Lasse Collin <lasse.collin@tukaani.org>
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
#ifndef XZ_STREAM_H
#define XZ_STREAM_H
#if defined(__KERNEL__) && !XZ_INTERNAL_CRC32
# include <linux/crc32.h>
# undef crc32
# define xz_crc32(buf, size, crc) \
(~crc32_le(~(uint32_t)(crc), buf, size))
#endif
/*
* See the .xz file format specification at
* http://tukaani.org/xz/xz-file-format.txt
* to understand the container format.
*/
#define STREAM_HEADER_SIZE 12
#define HEADER_MAGIC "\3757zXZ"
#define HEADER_MAGIC_SIZE 6
#define FOOTER_MAGIC "YZ"
#define FOOTER_MAGIC_SIZE 2
/*
* Variable-length integer can hold a 63-bit unsigned integer or a special
* value indicating that the value is unknown.
*
* Experimental: vli_type can be defined to uint32_t to save a few bytes
* in code size (no effect on speed). Doing so limits the uncompressed and
* compressed size of the file to less than 256 MiB and may also weaken
* error detection slightly.
*/
typedef uint64_t vli_type;
#define VLI_MAX ((vli_type)-1 / 2)
#define VLI_UNKNOWN ((vli_type)-1)
/* Maximum encoded size of a VLI */
#define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7)
/* Integrity Check types */
enum xz_check {
XZ_CHECK_NONE = 0,
XZ_CHECK_CRC32 = 1,
XZ_CHECK_CRC64 = 4,
XZ_CHECK_SHA256 = 10
};
/* Maximum possible Check ID */
#define XZ_CHECK_MAX 15
#endif