From cfa20459f6e532484c2d4ef2c17f313207c450b1 Mon Sep 17 00:00:00 2001 From: Robert Pengelly Date: Sat, 28 Feb 2026 22:38:29 +0000 Subject: [PATCH 1/1] Initial commit --- LICENSE | 24 + Makefile.unix | 27 + Makefile.w32 | 21 + README.md | 27 + include/stdint.h | 49 ++ include/xz.h | 244 +++++++ include/xz_lzma2.h | 202 ++++++ lib.c | 227 +++++++ lib.h | 15 + libxz/xz_crc32.c | 40 ++ libxz/xz_crc64.c | 40 ++ libxz/xz_dec_bcj.c | 611 ++++++++++++++++++ libxz/xz_dec_lzma2.c | 1421 +++++++++++++++++++++++++++++++++++++++++ libxz/xz_dec_stream.c | 984 ++++++++++++++++++++++++++++ report.c | 150 +++++ report.h | 29 + unxz.c | 179 ++++++ unxz.h | 17 + 18 files changed, 4307 insertions(+) create mode 100755 LICENSE create mode 100755 Makefile.unix create mode 100755 Makefile.w32 create mode 100755 README.md create mode 100644 include/stdint.h create mode 100644 include/xz.h create mode 100644 include/xz_lzma2.h create mode 100755 lib.c create mode 100755 lib.h create mode 100644 libxz/xz_crc32.c create mode 100644 libxz/xz_crc64.c create mode 100644 libxz/xz_dec_bcj.c create mode 100644 libxz/xz_dec_lzma2.c create mode 100644 libxz/xz_dec_stream.c create mode 100644 report.c create mode 100644 report.h create mode 100644 unxz.c create mode 100755 unxz.h diff --git a/LICENSE b/LICENSE new file mode 100755 index 0000000..fdddb29 --- /dev/null +++ b/LICENSE @@ -0,0 +1,24 @@ +This is free and unencumbered software released into the public domain. + +Anyone is free to copy, modify, publish, use, compile, sell, or +distribute this software, either in source code form or as a compiled +binary, for any purpose, commercial or non-commercial, and by any +means. + +In jurisdictions that recognize copyright laws, the author or authors +of this software dedicate any and all copyright interest in the +software to the public domain. We make this dedication for the benefit +of the public at large and to the detriment of our heirs and +successors. We intend this dedication to be an overt act of +relinquishment in perpetuity of all present and future rights to this +software under copyright law. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR +OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, +ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR +OTHER DEALINGS IN THE SOFTWARE. + +For more information, please refer to diff --git a/Makefile.unix b/Makefile.unix new file mode 100755 index 0000000..72af46d --- /dev/null +++ b/Makefile.unix @@ -0,0 +1,27 @@ +#****************************************************************************** +# @file Makefile.unix +#****************************************************************************** +SRCDIR ?= $(CURDIR) +VPATH := $(SRCDIR) + +CC := gcc +CFLAGS := -D_FILE_OFFSET_BITS=64 -I$(SRCDIR)/include -O2 -Wall -Werror -Wextra -std=c90 + +CSRC := libxz/xz_crc32.c libxz/xz_crc64.c libxz/xz_dec_lzma2.c libxz/xz_dec_stream.c lib.c report.c unxz.c + +ifeq ($(OS), Windows_NT) +all: unxz.exe + +unxz.exe: $(CSRC) + $(CC) $(CFLAGS) -o $@ $^ +else +all: unxz + +unxz: $(CSRC) + $(CC) $(CFLAGS) -o $@ $^ +endif + +clean: + + if [ -f unxz ]; then rm -rf unxz; fi + if [ -f unxz.exe ]; then rm -rf unxz.exe; fi diff --git a/Makefile.w32 b/Makefile.w32 new file mode 100755 index 0000000..79091ad --- /dev/null +++ b/Makefile.w32 @@ -0,0 +1,21 @@ +#****************************************************************************** +# @file Makefile.w32 +#****************************************************************************** +SRCDIR ?= $(CURDIR) +VPATH := $(SRCDIR) + +CC := gcc +CFLAGS := -D_FILE_OFFSET_BITS=64 -I$(SRCDIR)/include -O2 -Wall -Werror -Wextra + +CSRC := libxz/xz_crc32.c libxz/xz_crc64.c libxz/xz_dec_lzma2.c libxz/xz_dec_stream.c lib.c report.c unxz.c + +all: unxz.exe + +clean: + + if exist unxz ( del /q unxz ) + if exist unxz.exe ( del /q unxz.exe ) + +unxz.exe: $(CSRC) + + $(CC) $(CFLAGS) -o $@ $^ diff --git a/README.md b/README.md new file mode 100755 index 0000000..7b3a445 --- /dev/null +++ b/README.md @@ -0,0 +1,27 @@ +## License + + All source code is Public Domain. + +## Obtain the source code + + git clone https://git.candlhat.org/unxz.git + +## Building + + BSD: + + Make sure you have gcc and gmake installed then run gmake -f Makefile.unix. + + Linux: + + Make sure you have gcc and make installed then run make -f Makefile.unix. + + macOS: + + Make sure you have xcode command line tools installed then run + make -f Makefile.unix. + + Windows: + + Make sure you have mingw installed and the location within your PATH variable + then run mingw32-make.exe -f Makefile.w32. diff --git a/include/stdint.h b/include/stdint.h new file mode 100644 index 0000000..1b97ab8 --- /dev/null +++ b/include/stdint.h @@ -0,0 +1,49 @@ +/****************************************************************************** + * @file stdint.h + *****************************************************************************/ +#ifndef _STDINT_H_INCLUDED +#ifndef _STDINT_H +#ifndef _STDINT_H_ + +#define _STDINT_H_INCLUDED +#define _STDINT_H +#define _STDINT_H_ + +#include + +/* Add all data types (even though we don't use them) as the project seems to fail to build on some systems. */ +typedef signed char int8_t; +typedef unsigned char uint8_t; + +typedef signed short int16_t; +typedef unsigned short uint16_t; + +#if INT_MAX > 32767 +typedef signed int int32_t; +typedef unsigned int uint32_t; +#else +typedef signed long int32_t; +typedef unsigned long uint32_t; +#endif + +#ifndef _INT64_T +#define _INT64_T +#if defined (NO_LONG_LONG) || ((ULONG_MAX >> 16) >> 16) == 0xffffffff +typedef signed long int64_t; +#else +typedef signed long long int64_t; +#endif +#endif /* _INT64_T */ + +#ifndef _UINT64_T +#define _UINT64_T +#if defined (NO_LONG_LONG) || ((ULONG_MAX >> 16) >> 16) == 0xffffffff +typedef unsigned long uint64_t; +#else +typedef unsigned long long uint64_t; +#endif +#endif /* _UINT64_T */ + +#endif /* _STDINT_H_ */ +#endif /* _STDINT_H */ +#endif /* _STDINT_H_INCLUDED */ diff --git a/include/xz.h b/include/xz.h new file mode 100644 index 0000000..7e1ccd4 --- /dev/null +++ b/include/xz.h @@ -0,0 +1,244 @@ +#ifndef _XZ_H +#define _XZ_H + +/** + * 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 + +}; + +#include + +/** + * 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 { + + uint8_t *in; + uint64_t in_pos; + uint64_t in_size; + + uint8_t *out; + uint64_t out_pos; + uint64_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. + */ +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. + */ +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. + */ +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. + */ +extern void xz_dec_end (struct xz_dec *s); + + +/** + * This must be called before any other xz_* function to initialize + * the CRC32 lookup table. + */ +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. + */ +extern uint32_t xz_crc32 (const uint8_t *buf, uint64_t size, uint32_t crc); + + +/* + * This must be called before any other xz_* function (except xz_crc32_init()) + * to initialize the CRC64 lookup table. + */ +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. + */ +extern uint64_t xz_crc64 (const uint8_t *buf, uint64_t size, uint64_t crc); + +#endif /* _XZ_H */ \ No newline at end of file diff --git a/include/xz_lzma2.h b/include/xz_lzma2.h new file mode 100644 index 0000000..2a8abf4 --- /dev/null +++ b/include/xz_lzma2.h @@ -0,0 +1,202 @@ +#ifndef _XZ_LZMA2_H +#define _XZ_LZMA2_H + +#include + +/* Range coder constants */ +#define RC_TOP_BITS 24 +#define RC_BIT_MODEL_TOTAL_BITS 11 + +#define RC_SHIFT_BITS 8 +#define RC_MOVE_BITS 5 + +#define RC_TOP_VALUE (1 << RC_TOP_BITS) +#define RC_BIT_MODEL_TOTAL (1 << RC_BIT_MODEL_TOTAL_BITS) + +/* + * 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 (int *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_MID_BITS 3 +#define LEN_HIGH_BITS 8 + +#define LEN_LOW_SYMBOLS (1 << LEN_LOW_BITS) +#define LEN_MID_SYMBOLS (1 << LEN_MID_BITS) +#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 /* _XZ_LZMA2_H */ \ No newline at end of file diff --git a/lib.c b/lib.c new file mode 100755 index 0000000..91822f3 --- /dev/null +++ b/lib.c @@ -0,0 +1,227 @@ +/****************************************************************************** + * @file lib.c + *****************************************************************************/ +#include +#include +#include +#include +#include +#include +#include + +#include "lib.h" +#include "report.h" +#include "unxz.h" + +#define OPTION_HELP 0x0001 + +struct option { + + const char *name; + int index, flags; + +}; + +#define OPTION_NO_ARG 0x0001 +#define OPTION_HAS_ARG 0x0002 + +static struct option opts[] = { + + { "--help", OPTION_HELP, OPTION_NO_ARG }, + { 0, 0, 0 } + +}; + +static int strstart (const char *val, const char **str) { + + const char *p = val; + const char *q = *str; + + while (*p != '\0') { + + if (*p != *q) { + return 0; + } + + ++p; + ++q; + + } + + *str = q; + return 1; + +} + +static void print_help (void) { + + if (program_name) { + + fprintf (stderr, "Usage: %s [opts] file... [-x xlist]\n\n", program_name); + fprintf (stderr, "Options:\n\n"); + + fprintf (stderr, " --help Show this help information then exit.\n"); + + } + + exit (EXIT_SUCCESS); + +} + +static void dynarray_add (void *ptab, long *nb_ptr, void *data) { + + int nb, nb_alloc; + void **pp; + + nb = *nb_ptr; + pp = *(void ***) ptab; + + if ((nb & (nb - 1)) == 0) { + + if (!nb) { + nb_alloc = 1; + } else { + nb_alloc = nb * 2; + } + + pp = xrealloc (pp, nb_alloc * sizeof (void *)); + *(void ***) ptab = pp; + + } + + pp[nb++] = data; + *nb_ptr = nb; + +} + +void parse_args (int argc, char **argv, int optind) { + + struct option *popt; + const char *optarg, *r; + + if (argc <= optind) { + print_help (); + } + + while (optind < argc) { + + r = argv[optind++]; + + if (r[0] != '-' || r[1] == '\0') { + + dynarray_add (&state->files, &state->nb_files, xstrdup (r)); + continue; + + } + + for (popt = opts; popt; popt++) { + + const char *p1 = popt->name; + const char *r1 = r; + + if (!p1) { + + report_at (program_name, 0, REPORT_ERROR, "invalid option -- '%s'", r); + exit (EXIT_FAILURE); + + } + + if (!strstart (p1, &r1)) { + continue; + } + + optarg = r1; + + if (popt->flags & OPTION_HAS_ARG) { + + if (*optarg == '\0') { + + if (optind >= argc) { + + report_at (program_name, 0, REPORT_ERROR, "argument to '%s' is missing", r); + exit (EXIT_FAILURE); + + } + + optarg = argv[optind++]; + + } + + } else if (*optarg != '\0') { + continue; + } + + break; + + } + + switch (popt->index) { + + case OPTION_HELP: { + + print_help (); + break; + + } + + default: { + + report_at (program_name, 0, REPORT_ERROR, "unsupported option '%s'", r); + exit (EXIT_FAILURE); + + } + + } + + } + +} + +char *xstrdup (const char *str) { + + char *ptr = xmalloc (strlen (str) + 1); + strcpy (ptr, str); + + return ptr; + +} + +char *xstrndup (const char *str, unsigned long len) { + + char *p = xmalloc (len + 1); + + memcpy (p, str, len); + return p; + +} + +void *xmalloc (unsigned long size) { + + void *ptr = malloc (size); + + if (ptr == NULL && size) { + + report_at (program_name, 0, REPORT_ERROR, "memory full (malloc)"); + exit (EXIT_FAILURE); + + } + + memset (ptr, 0, size); + return ptr; + +} + +void *xrealloc (void *ptr, unsigned long size) { + + void *new_ptr = realloc (ptr, size); + + if (new_ptr == NULL && size) { + + report_at (program_name, 0, REPORT_ERROR, "memory full (realloc)"); + exit (EXIT_FAILURE); + + } + + return new_ptr; + +} diff --git a/lib.h b/lib.h new file mode 100755 index 0000000..80dcc0b --- /dev/null +++ b/lib.h @@ -0,0 +1,15 @@ +/****************************************************************************** + * @file lib.h + *****************************************************************************/ +#ifndef _LIB_H +#define _LIB_H + +char *xstrdup (const char *str); +char *xstrndup (const char *str, unsigned long len); + +void *xmalloc (unsigned long size); +void *xrealloc (void *ptr, unsigned long size); + +void parse_args (int argc, char **argv, int optind); + +#endif /* _LIB_H */ diff --git a/libxz/xz_crc32.c b/libxz/xz_crc32.c new file mode 100644 index 0000000..27d644c --- /dev/null +++ b/libxz/xz_crc32.c @@ -0,0 +1,40 @@ +/****************************************************************************** + * @file xz_crc32.c + *****************************************************************************/ +#include + +static uint32_t xz_crc32_table[256]; + +uint32_t xz_crc32 (const uint8_t *buf, uint64_t size, uint32_t crc) { + + crc = ~crc; + + while (size != 0) { + + crc = xz_crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8); + size--; + + } + + return ~crc; + +} + +void xz_crc32_init (void) { + + const uint32_t poly = 0xEDB88320; + uint32_t i, j, 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; + + } + +} diff --git a/libxz/xz_crc64.c b/libxz/xz_crc64.c new file mode 100644 index 0000000..719a39e --- /dev/null +++ b/libxz/xz_crc64.c @@ -0,0 +1,40 @@ +/****************************************************************************** + * @file xz_crc64.c + *****************************************************************************/ +#include + +static uint64_t xz_crc64_table[256]; + +uint64_t xz_crc64 (const uint8_t *buf, uint64_t size, uint64_t crc) { + + crc = ~crc; + + while (size != 0) { + + crc = xz_crc64_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8); + size--; + + } + + return ~crc; + +} + +void xz_crc64_init (void) { + + const uint64_t poly = 0xC96C5795D7870F42ULL; + uint64_t i, j, r; + + for (i = 0; i < 256; i++) { + + r = i; + + for (j = 0; j < 8; j++) { + r = (r >> 1) ^ (poly & ~((r & 1) - 1)); + } + + xz_crc64_table[i] = r; + + } + +} diff --git a/libxz/xz_dec_bcj.c b/libxz/xz_dec_bcj.c new file mode 100644 index 0000000..0a79a93 --- /dev/null +++ b/libxz/xz_dec_bcj.c @@ -0,0 +1,611 @@ +/****************************************************************************** + * @file xz_dec_bcj.c + *****************************************************************************/ +#include +#include + +struct xz_dec_bcj { + + /* Type of the BCJ filter being used */ + enum { + + BCJ_X86 = 4, /* x86 or x86-64 */ + BCJ_POWERPC = 5, /* Big endian only */ + BCJ_IA64 = 6, /* Big or little endian */ + BCJ_ARM = 7, /* Little endian only */ + BCJ_ARMTHUMB = 8, /* Little endian only */ + BCJ_SPARC = 9 /* Big or little endian */ + + } type; + + /** + * Return value of the next filter in the chain. We need to preserve + * this information across calls, because we must not call the next + * filter anymore once it has returned XZ_STREAM_END. + */ + enum xz_ret ret; + + /* True if we are operating in single-call mode. */ + int single_call; + + /** + * Absolute position relative to the beginning of the uncompressed + * data (in a single .xz Block). We care only about the lowest 32 + * bits so this doesn't need to be uint64_t even with big files. + */ + uint32_t pos; + + /* x86 filter state */ + uint32_t x86_prev_mask; + + /* Temporary space to hold the variables from struct xz_buf */ + uint8_t *out; + + uint64_t out_pos; + uint64_t out_size; + + struct { + + /* Amount of already filtered data in the beginning of buf */ + uint64_t filtered; + + /* Total amount of data currently stored in buf */ + uint64_t size; + + /* + * Buffer to hold a mix of filtered and unfiltered data. This + * needs to be big enough to hold Alignment + 2 * Look-ahead: + * + * Type Alignment Look-ahead + * --------------------------------------- + * x86 1 4 + * PowerPC 4 0 + * IA-64 16 0 + * ARM 4 0 + * ARM-Thumb 2 2 + * SPARC 4 0 + */ + uint8_t buf[16]; + + } temp; + +}; + +/** + * This is used to test the most significant byte of a memory address + * in an x86 instruction. + */ +static int bcj_x86_test_msbyte (uint8_t b) { + return (b == 0 || b == 8); +} + +static uint64_t bcj_x86 (struct xz_dec_bcj *s, uint8_t *buf, uint64_t size) { + + static const int mask_to_allowed_status[8] = { 1, 1, 1, 0, 1, 0, 0, 0 }; + static const uint8_t mask_to_bit_num[8] = { 0, 1, 2, 2, 3, 3, 3, 3 }; + + uint32_t prev_mask = s->x86_prev_mask; + uint64_t prev_pos = -1, i; + + uint32_t src, dest, j; + uint8_t b; + + if (size <= 4) { + return 0; + } + + size -= 4; + + for (i = 0; i < size; i++) { + + if ((buf[i] & 0xFE) != 0xE8) { + continue; + } + + if ((prev_pos = i - prev_pos)) { + prev_mask = 0; + } else { + + if ((prev_mask = (prev_mask << (prev_pos - 1)) & 7)) { + + b = buf[i + 4 - mask_to_bit_num[prev_mask]]; + + if (!mask_to_allowed_status[prev_mask] || bcj_x86_test_msbyte (b)) { + + prev_pos = i; + + prev_mask = (prev_mask << 1) | 1; + continue; + + } + + } + + } + + prev_pos = i; + + if (bcj_x86_test_msbyte (buf[i + 4])) { + + src = get_unaligned_le32 (buf + i + 1); + + for (;;) { + + dest = src - (s->pos + (uint32_t) i + 5); + + if (!prev_mask) { + break; + } + + j = mask_to_bit_num[prev_mask] * 8; + b = (uint8_t) (dest >> 24 - j); + + if (!bcj_x86_test_msbyte (b)) { + break; + } + + src = dest ^ (((uint32_t) 1 << (32 - j)) - 1); + + } + + dest &= 0x01FFFFFF; + + dest |= (uint32_t) 0 - (dest & 0x01000000); + put_unaligned_le32 (dest, buf + i + 1); + + i += 4; + + } else { + prev_mask = (prev_mask << 1) | 1; + } + + } + + prev_pos = i - prev_pos; + + s->x86_prev_mask = (prev_pos > 3) ? 0 : (prev_mask << (prev_pos - 1)); + return i; + +} + +static uint64_t bcj_arm (struct xz_dec_bcj *s, uint8_t *buf, uint64_t size) { + + uint32_t addr; + uint64_t i; + + for (i = 0; i + 4 <= size; i+= 4) { + + if (buf[i + 3] == 0xEB) { + + addr = (uint32_t) buf[i] | ((uint32_t) buf[i + 1] << 8) | ((uint32_t) buf[i + 2] << 16); + addr <<= 2; + + addr -= s->pos + (uint32_t) i + 8; + addr >>= 2; + + buf[i] = (uint8_t) addr; + + buf[i + 1] = (uint8_t) (addr >> 8); + buf[i + 2] = (uint8_t) (addr >> 16); + + } + + } + + return i; + +} + +static uint64_t bcj_armthumb (struct xz_dec_bcj *s, uint8_t *buf, uint64_t size) { + + uint32_t addr; + uint64_t i; + + for (i = 0; i + 4 <= size; i += 2) { + + if ((buf[i + 1] & 0xF8) == 0xF0 && (buf[i + 3] & 0xF8) == 0xF8) { + + addr = (((uint32_t) buf[i + 1] & 0x07) << 19) | ((uint32_t) buf[i] << 11) | (((uint32_t) buf[i + 3] & 0x07) << 8) | (uint32_t) buf[i + 2]; + addr <<= 1; + + addr -= s->pos + (uint32_t) i + 4; + addr >>= 1; + + buf[i + 1] = (uint8_t) (0xF0 | ((addr >> 19) & 0x07)); + buf[i] = (uint8_t) (addr >> 11); + + buf[i + 3] = (uint8_t) (0xF8 | ((addr >> 8) & 0x07)); + buf[i + 2] = (uint8_t) addr; + + i += 2; + + } + + } + + return i; + +} + +static uint64_t bcj_powerpc (struct xz_dec_bcj *s, uint8_t *buf, uint64_t size) { + + uint32_t instr; + uint64_t i; + + for (i = 0; i + 4 <= size; i += 4) { + + instr = get_unaligned_be32 (buf + i); + + if ((instr & 0xFC000003) == 0x48000001) { + + instr &= 0x03FFFFFC; + + instr -= s->pos + (uint32_t) i; + instr &= 0x03FFFFFC; + + instr |= 0x48000001; + put_unaligned_be32 (instr, buf + i); + + } + + } + + return i; + +} + +static uint64_t bcj_sparc (struct xz_dec_bcj *s, uint8_t *buf, uint64_t size) { + + uint32_t instr; + uint64_t i; + + for (i = 0; i + 4 <= size; i += 4) { + + instr = get_unaligned_be32 (buf + i); + + if ((instr >> 22) == 0x100 || (instr >> 22) == 0x1FF) { + + instr <<= 2; + + instr -= s->pos + (uint32_t) i; + instr >>= 2; + + instr = ((uint32_t) 0x40000000 - (instr & 0x400000)) | 0x40000000 | (instr & 0x3FFFFF); + put_unaligned_be32 (instr, buf + i); + + } + + } + + return i; + +} + +static uint64_t bcj_ia64 (struct xz_dec_bcj *s, uint8_t *buf, uint64_t size) { + + static const uint8_t branch_table[32] = { + + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + 4, 4, 6, 6, 0, 0, 7, 7, + 4, 4, 0, 0, 4, 4, 0, 0 + + }; + + uint64_t i, j; + + /* Instruction slot (0, 1 or 2) in the 128-bit instruction word. */ + uint32_t slot; + + /* Bitwise offset of the instruction indicated by slot. */ + uint32_t bit_pos; + + /* bit-pos split into byte and bit parts. */ + uint32_t byte_pos, bit_res; + + /* Address part of an instruction. */ + uint32_t addr; + + /* Mask used to detect which instruction to convert. */ + uint32_t mask; + + /* 41-bit instruction stored somewhere in the lowest 48 bits. */ + uint64_t instr; + + /* Instruction normalized with bit_res for easier manipulation. */ + uint64_t norm; + + for (i = 0; i + 16 <= size; i += 16) { + + mask = branch_table[buf[i] & 0x3F]; + + for (slot = 0, bit_pos = 5; slot < 3; slot++, bit_pos += 41) { + + if (((mask >> slot) & 1) == 0) { + continue; + } + + byte_pos = bit_pos >> 3; + bit_res = bit_pos & 7; + + instr = 0; + + for (j = 0; j < 6; j++) { + instr |= (uint64_t) (buf[i + j + byte_pos]) << (8 * j); + } + + norm = instr >> bit_res; + + if (((norm >> 37) & 0x0F) == 0x05 && ((norm >> 9) & 0x07) == 0) { + + addr = (norm >> 13) & 0x0FFFFF; + + addr |= ((uint32_t)(norm >> 36) & 1) << 20; + addr <<= 4; + + addr -= s->pos + (uint32_t)i; + addr >>= 4; + + norm &= ~((uint64_t)0x8FFFFF << 13); + norm |= (uint64_t)(addr & 0x0FFFFF) << 13; + norm |= (uint64_t)(addr & 0x100000) << (36 - 20); + + instr &= (1 << bit_res) - 1; + instr |= norm << bit_res; + + for (j = 0; j < 6; j++) { + buf[i + j + byte_pos] = (uint8_t) (instr >> (8 * j)); + } + + } + + } + + } + + return i; + +} + +/** + * Apply the selected BCJ filter. Update *pos and s->pos to match the amount + * of data that got filtered. + * + * NOTE: This is implemented as a switch statement to avoid using function + * pointers, which could be problematic in the kernel boot code, which must + * avoid pointers to static data (at least on x86). + */ +static void bcj_apply (struct xz_dec_bcj *s, uint8_t *buf, uint64_t *pos, uint64_t size) { + + uint64_t filtered; + + buf += *pos; + size -= *pos; + + switch (s->type) { + + case BCJ_X86: + + filtered = bcj_x86 (s, buf, size); + break; + + case BCJ_POWERPC: + + filtered = bcj_powerpc (s, buf, size); + break; + + case BCJ_IA64: + + filtered = bcj_ia64 (s, buf, size); + break; + + case BCJ_ARM: + + filtered = bcj_arm (s, buf, size); + break; + + case BCJ_ARMTHUMB: + + filtered = bcj_armthumb (s, buf, size); + break; + + case BCJ_SPARC: + + filtered = bcj_sparc (s, buf, size); + break; + + default: + + /* Never reached but silence compiler warnings. */ + filtered = 0; + break; + + } + + *pos += filtered; + s->pos += filtered; + +} + +#ifndef MIN +# define MIN(x, y) ((x) < (y) ? (x) : (y)) +#endif + +/** + * Flush pending filtered data from temp to the output buffer. + * Move the remaining mixture of possibly filtered and unfiltered + * data to the beginning of temp. + */ +static void bcj_flush (struct xz_dec_bcj *s, struct xz_buf *b) { + + uint64_t copy_size; + + copy_size = MIN (s->temp.filtered, b->out_size - b->out_pos); + memcpy (b->out + b->out_pos, s->temp.buf, copy_size); + + b->out_pos += copy_size; + + s->temp.filtered -= copy_size; + s->temp.size -= copy_size; + memmove (s->temp.buf, s->temp.buf + copy_size, s->temp.size); + +} + +/** + * The BCJ filter functions are primitive in sense that they process the + * data in chunks of 1-16 bytes. To hide this issue, this function does + * some buffering. + */ +enum xz_ret xz_dec_bcj_run (struct xz_dec_bcj *s, struct xz_dec_lzma2 *lzma2, struct xz_buf *b) { + + uint64_t out_start; + + /* + * Flush pending already filtered data to the output buffer. Return + * immediatelly if we couldn't flush everything, or if the next + * filter in the chain had already returned XZ_STREAM_END. + */ + if (s->temp.filtered > 0) { + + bcj_flush (s, b); + + if (s->temp.filtered > 0) { + return XZ_OK; + } + + if (s->ret == XZ_STREAM_END) { + return XZ_STREAM_END; + } + + } + + /* + * If we have more output space than what is currently pending in + * temp, copy the unfiltered data from temp to the output buffer + * and try to fill the output buffer by decoding more data from the + * next filter in the chain. Apply the BCJ filter on the new data + * in the output buffer. If everything cannot be filtered, copy it + * to temp and rewind the output buffer position accordingly. + */ + if (s->temp.size < b->out_size - b->out_pos) { + + out_start = b->out_pos; + + memcpy (b->out + b->out_pos, s->temp.buf, s->temp.size); + b->out_pos += s->temp.size; + + s->ret = xz_dec_lzma2_run (lzma2, b); + + if (s->ret != XZ_STREAM_END && (s->ret != XZ_OK || s->single_call)) { + return s->ret; + } + + bcj_apply (s, b->out, &out_start, b->out_pos); + + /* + * As an exception, if the next filter returned XZ_STREAM_END, + * we can do that too, since the last few bytes that remain + * unfiltered are meant to remain unfiltered. + */ + if (s->ret == XZ_STREAM_END) { + return XZ_STREAM_END; + } + + s->temp.size = b->out_pos - out_start; + b->out_pos -= s->temp.size; + + memcpy (s->temp.buf, b->out + b->out_pos, s->temp.size); + + } + + /* + * If we have unfiltered data in temp, try to fill by decoding more + * data from the next filter. Apply the BCJ filter on temp. Then we + * hopefully can fill the actual output buffer by copying filtered + * data from temp. A mix of filtered and unfiltered data may be left + * in temp; it will be taken care on the next call to this function. + */ + if (s->temp.size > 0) { + + /* Make b->out{,_pos,_size} temporarily point to s->temp. */ + s->out = b->out; + s->out_pos = b->out_pos; + s->out_size = b->out_size; + b->out = s->temp.buf; + b->out_pos = s->temp.size; + b->out_size = sizeof(s->temp.buf); + + s->ret = xz_dec_lzma2_run (lzma2, b); + + s->temp.size = b->out_pos; + b->out = s->out; + b->out_pos = s->out_pos; + b->out_size = s->out_size; + + if (s->ret != XZ_OK && s->ret != XZ_STREAM_END) { + return s->ret; + } + + bcj_apply (s, s->temp.buf, &s->temp.filtered, s->temp.size); + + /* + * If the next filter returned XZ_STREAM_END, we mark that + * everything is filtered, since the last unfiltered bytes + * of the stream are meant to be left as is. + */ + if (s->ret == XZ_STREAM_END) { + s->temp.filtered = s->temp.size; + } + + bcj_flush (s, b); + + if (s->temp.filtered > 0) { + return XZ_OK; + } + + } + + return s->ret; + +} + +struct xz_dec_bcj *xz_dec_bcj_create (int single_call) { + + struct xz_dec_bcj *s; + + if ((s = malloc (sizeof (*s)))) { + s->single_call = single_call; + } + + return s; + +} + +enum xz_ret xz_dec_bcj_reset (struct xz_dec_bcj *s, uint8_t id) { + + switch (id) { + + case BCJ_X86: case BCJ_POWERPC: + case BCJ_IA64: case BCJ_ARM: + case BCJ_ARMTHUMB: case BCJ_SPARC: + + break; + + default: + + /* Unsupported Filter ID */ + return XZ_OPTIONS_ERROR; + + } + + s->type = id; + s->ret = XZ_OK; + s->pos = 0; + + s->x86_prev_mask = 0; + s->temp.filtered = 0; + s->temp.size = 0; + + return XZ_OK; + +} diff --git a/libxz/xz_dec_lzma2.c b/libxz/xz_dec_lzma2.c new file mode 100644 index 0000000..1f2deb4 --- /dev/null +++ b/libxz/xz_dec_lzma2.c @@ -0,0 +1,1421 @@ +/****************************************************************************** + * @file xz_dec_lzma2.c + *****************************************************************************/ +#include +#include +#include +#include + +#include +#include + +#ifndef MIN +# define MIN(x, y) ((x) < (y) ? (x) : (y)) +#endif + +#define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE) +#define DEC_IS_MULTI(mode) ((mode) != XZ_SINGLE) +#define DEC_IS_PREALLOC(mode) ((mode) == XZ_PREALLOC) +#define DEC_IS_DYNALLOC(mode) ((mode) == XZ_DYNALLOC) + +/* Indicate that the latest symbol was a literal. */ +static void lzma_state_literal (int *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 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 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 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 int lzma_state_is_literal (enum lzma_state state) { + return state < LIT_STATES; +} + +/** + * Get the index of the appropriate probability array for decoding + * the distance slot. + */ +static uint32_t lzma_get_dist_state (uint32_t len) { + return len < DIST_STATES + MATCH_LEN_MIN ? len - MATCH_LEN_MIN : DIST_STATES - 1; +} + +/* Range decoder initialization eats the first five bytes of each LZMA chunk. */ +#define RC_INIT_BYTES 5 + +/* + * Minimum number of usable input buffer to safely decode one LZMA symbol. + * The worst case is that we decode 22 bits using probabilities and 26 + * direct bits. This may decode at maximum of 20 bytes of input. However, + * lzma_main() does an extra normalization before returning, thus we + * need to put 21 here. + */ +#define LZMA_IN_REQUIRED 21 + +/* + * Dictionary (history buffer) + * + * These are always true: + * start <= pos <= full <= end + * pos <= limit <= end + * + * In multi-call mode, also these are true: + * end == size + * size <= size_max + * allocated <= size + * + * Most of these variables are size_t to support single-call mode, + * in which the dictionary variables address the actual output + * buffer directly. + */ +struct dictionary { + + /* Beginning of the history buffer */ + uint8_t *buf; + + /* Old position in buf (before decoding more data) */ + uint64_t start; + + /* Position in buf */ + uint64_t pos; + + /* + * How full dictionary is. This is used to detect corrupt input that + * would read beyond the beginning of the uncompressed stream. + */ + uint64_t full; + + /* Write limit; we don't write to buf[limit] or later bytes. */ + uint64_t limit; + + /* + * End of the dictionary buffer. In multi-call mode, this is + * the same as the dictionary size. In single-call mode, this + * indicates the size of the output buffer. + */ + uint64_t end; + + /* + * Size of the dictionary as specified in Block Header. This is used + * together with "full" to detect corrupt input that would make us + * read beyond the beginning of the uncompressed stream. + */ + uint32_t size; + + /* + * Maximum allowed dictionary size in multi-call mode. + * This is ignored in single-call mode. + */ + uint32_t size_max; + + /* + * Amount of memory currently allocated for the dictionary. + * This is used only with XZ_DYNALLOC. (With XZ_PREALLOC, + * size_max is always the same as the allocated size.) + */ + uint32_t allocated; + + /* Operation mode */ + enum xz_mode mode; + +}; + +/* Range decoder */ +struct rc_dec { + + uint32_t range; + uint32_t code; + + /* + * Number of initializing bytes remaining to be read + * by rc_read_init(). + */ + uint32_t init_bytes_left; + + /* + * Buffer from which we read our input. It can be either + * temp.buf or the caller-provided input buffer. + */ + const uint8_t *in; + uint64_t in_pos; + uint64_t in_limit; + +}; + +/* Probabilities for a length decoder. */ +struct lzma_len_dec { + + /* Probability of match length being at least 10 */ + uint16_t choice; + + /* Probability of match length being at least 18 */ + uint16_t choice2; + + /* Probabilities for match lengths 2-9 */ + uint16_t low[POS_STATES_MAX][LEN_LOW_SYMBOLS]; + + /* Probabilities for match lengths 10-17 */ + uint16_t mid[POS_STATES_MAX][LEN_MID_SYMBOLS]; + + /* Probabilities for match lengths 18-273 */ + uint16_t high[LEN_HIGH_SYMBOLS]; + +}; + +struct lzma_dec { + + /* Distances of latest four matches */ + uint32_t rep0; + uint32_t rep1; + uint32_t rep2; + uint32_t rep3; + + /* Types of the most recently seen LZMA symbols */ + enum lzma_state state; + + /* + * Length of a match. This is updated so that dict_repeat can + * be called again to finish repeating the whole match. + */ + uint32_t len; + + /* + * LZMA properties or related bit masks (number of literal + * context bits, a mask dervied from the number of literal + * position bits, and a mask dervied from the number + * position bits) + */ + uint32_t lc; + uint32_t literal_pos_mask; /* (1 << lp) - 1 */ + uint32_t pos_mask; /* (1 << pb) - 1 */ + + /* If 1, it's a match. Otherwise it's a single 8-bit literal. */ + uint16_t is_match[STATES][POS_STATES_MAX]; + + /* If 1, it's a repeated match. The distance is one of rep0 .. rep3. */ + uint16_t is_rep[STATES]; + + /* + * If 0, distance of a repeated match is rep0. + * Otherwise check is_rep1. + */ + uint16_t is_rep0[STATES]; + + /* + * If 0, distance of a repeated match is rep1. + * Otherwise check is_rep2. + */ + uint16_t is_rep1[STATES]; + + /* If 0, distance of a repeated match is rep2. Otherwise it is rep3. */ + uint16_t is_rep2[STATES]; + + /* + * If 1, the repeated match has length of one byte. Otherwise + * the length is decoded from rep_len_decoder. + */ + uint16_t is_rep0_long[STATES][POS_STATES_MAX]; + + /* + * Probability tree for the highest two bits of the match + * distance. There is a separate probability tree for match + * lengths of 2 (i.e. MATCH_LEN_MIN), 3, 4, and [5, 273]. + */ + uint16_t dist_slot[DIST_STATES][DIST_SLOTS]; + + /* + * Probility trees for additional bits for match distance + * when the distance is in the range [4, 127]. + */ + uint16_t dist_special[FULL_DISTANCES - DIST_MODEL_END]; + + /* + * Probability tree for the lowest four bits of a match + * distance that is equal to or greater than 128. + */ + uint16_t dist_align[ALIGN_SIZE]; + + /* Length of a normal match */ + struct lzma_len_dec match_len_dec; + + /* Length of a repeated match */ + struct lzma_len_dec rep_len_dec; + + /* Probabilities of literals */ + uint16_t literal[LITERAL_CODERS_MAX][LITERAL_CODER_SIZE]; + +}; + +struct lzma2_dec { + + /* Position in xz_dec_lzma2_run(). */ + enum lzma2_seq { + + SEQ_CONTROL, + SEQ_UNCOMPRESSED_1, + SEQ_UNCOMPRESSED_2, + SEQ_COMPRESSED_0, + SEQ_COMPRESSED_1, + SEQ_PROPERTIES, + SEQ_LZMA_PREPARE, + SEQ_LZMA_RUN, + SEQ_COPY + + } sequence; + + /* Next position after decoding the compressed size of the chunk. */ + enum lzma2_seq next_sequence; + + /* Uncompressed size of LZMA chunk (2 MiB at maximum) */ + uint32_t uncompressed; + + /* + * Compressed size of LZMA chunk or compressed/uncompressed + * size of uncompressed chunk (64 KiB at maximum) + */ + uint32_t compressed; + + /* + * True if dictionary reset is needed. This is false before + * the first chunk (LZMA or uncompressed). + */ + int need_dict_reset; + + /* + * True if new LZMA properties are needed. This is false + * before the first LZMA chunk. + */ + int need_props; + +}; + +struct xz_dec_lzma2 { + + /* + * The order below is important on x86 to reduce code size and + * it shouldn't hurt on other platforms. Everything up to and + * including lzma.pos_mask are in the first 128 bytes on x86-32, + * which allows using smaller instructions to access those + * variables. On x86-64, fewer variables fit into the first 128 + * bytes, but this is still the best order without sacrificing + * the readability by splitting the structures. + */ + struct rc_dec rc; + struct dictionary dict; + struct lzma2_dec lzma2; + struct lzma_dec lzma; + + /* + * Temporary buffer which holds small number of input bytes between + * decoder calls. See lzma2_lzma() for details. + */ + struct { + + uint32_t size; + uint8_t buf[3 * LZMA_IN_REQUIRED]; + + } temp; + +}; + +/* + * Reset the dictionary state. When in single-call mode, set up the beginning + * of the dictionary to point to the actual output buffer. + */ +static void dict_reset(struct dictionary *dict, struct xz_buf *b) { + + if (DEC_IS_SINGLE (dict->mode)) { + + dict->buf = b->out + b->out_pos; + dict->end = b->out_size - b->out_pos; + + } + + dict->start = 0; + dict->pos = 0; + dict->limit = 0; + dict->full = 0; + +} + +/* Set dictionary write limit */ +static void dict_limit (struct dictionary *dict, uint64_t out_max) +{ + + if (dict->end - dict->pos <= out_max) { + dict->limit = dict->end; + } else { + dict->limit = dict->pos + out_max; + } + +} + +/* Return true if at least one byte can be written into the dictionary. */ +static int dict_has_space (const struct dictionary *dict) { + return dict->pos < dict->limit; +} + +/** + * Get a byte from the dictionary at the given distance. The distance is + * assumed to valid, or as a special case, zero when the dictionary is + * still empty. This special case is needed for single-call decoding to + * avoid writing a '\0' to the end of the destination buffer. + */ +static uint32_t dict_get (const struct dictionary *dict, uint32_t dist) { + + uint64_t offset = dict->pos - dist - 1; + + if (dist >= dict->pos) { + offset += dict->end; + } + + return dict->full > 0 ? dict->buf[offset] : 0; + +} + +/** + * Put one byte into the dictionary. It is assumed that there is space + * for it. + */ +static void dict_put (struct dictionary *dict, uint8_t byte) { + + dict->buf[dict->pos++] = byte; + + if (dict->full < dict->pos) { + dict->full = dict->pos; + } + +} + +/** + * Repeat given number of bytes from the given distance. If the distance is + * invalid, false is returned. On success, true is returned and *len is + * updated to indicate how many bytes were left to be repeated. + */ +static int dict_repeat (struct dictionary *dict, uint32_t *len, uint32_t dist) { + + uint64_t back; + uint32_t left; + + if (dist >= dict->full || dist >= dict->size) { + return 0; + } + + left = MIN (dict->limit - dict->pos, *len); + *len -= left; + + back = dict->pos - dist - 1; + + if (dist >= dict->pos) { + back += dict->end; + } + + do { + + dict->buf[dict->pos++] = dict->buf[back++]; + + if (back == dict->end) { + back = 0; + } + + } while (--left > 0); + + if (dict->full < dict->pos) { + dict->full = dict->pos; + } + + return 1; + +} + +/* Copy uncompressed data as is from input to dictionary and output buffers. */ +static void dict_uncompressed (struct dictionary *dict, struct xz_buf *b, uint32_t *left) { + + uint64_t copy_size; + + while (*left > 0 && b->in_pos < b->in_size && b->out_pos < b->out_size) { + + copy_size = MIN (b->in_size - b->in_pos, b->out_size - b->out_pos); + + if (copy_size > dict->end - dict->pos) { + copy_size = dict->end - dict->pos; + } + + if (copy_size > *left) { + copy_size = *left; + } + + *left -= copy_size; + + memmove (dict->buf + dict->pos, b->in + b->in_pos, copy_size); + dict->pos += copy_size; + + if (dict->full < dict->pos) { + dict->full = dict->pos; + } + + if (DEC_IS_MULTI (dict->mode)) { + + if (dict->pos == dict->end) { + dict->pos = 0; + } + + memmove (b->out + b->out_pos, b->in + b->in_pos, copy_size); + + } + + dict->start = dict->pos; + + b->out_pos += copy_size; + b->in_pos += copy_size; + + } + +} + +/* + * Flush pending data from dictionary to b->out. It is assumed that there is + * enough space in b->out. This is guaranteed because caller uses dict_limit() + * before decoding data into the dictionary. + */ +static uint32_t dict_flush (struct dictionary *dict, struct xz_buf *b) { + + uint32_t copy_size = dict->pos - dict->start; + + if (DEC_IS_MULTI (dict->mode)) { + + if (dict->pos == dict->end) { + dict->pos = 0; + } + + memcpy (b->out + b->out_pos, dict->buf + dict->start, copy_size); + + } + + dict->start = dict->pos; + b->out_pos += copy_size; + + return copy_size; + +} + +/* Reset the range decoder. */ +static void rc_reset (struct rc_dec *rc) { + + rc->range = (uint32_t)-1; + rc->code = 0; + rc->init_bytes_left = RC_INIT_BYTES; + +} + +/* + * Read the first five initial bytes into rc->code if they haven't been + * read already. (Yes, the first byte gets completely ignored.) + */ +static int rc_read_init (struct rc_dec *rc, struct xz_buf *b) { + + while (rc->init_bytes_left > 0) { + + if (b->in_pos == b->in_size) { + return 0; + } + + rc->code = (rc->code << 8) + b->in[b->in_pos++]; + --rc->init_bytes_left; + + } + + return 1; + +} + +/* Return true if there may not be enough input for the next decoding loop. */ +static int rc_limit_exceeded (const struct rc_dec *rc) { + return rc->in_pos > rc->in_limit; +} + +/* + * Return true if it is possible (from point of view of range decoder) that + * we have reached the end of the LZMA chunk. + */ +static int rc_is_finished (const struct rc_dec *rc) { + return rc->code == 0; +} + +/* Read the next input byte if needed. */ +static void rc_normalize (struct rc_dec *rc) { + + if (rc->range < RC_TOP_VALUE) { + + rc->range <<= RC_SHIFT_BITS; + rc->code = (rc->code << RC_SHIFT_BITS) + rc->in[rc->in_pos++]; + + } + +} + +/* + * Decode one bit. In some versions, this function has been splitted in three + * functions so that the compiler is supposed to be able to more easily avoid + * an extra branch. In this particular version of the LZMA decoder, this + * doesn't seem to be a good idea (tested with GCC 3.3.6, 3.4.6, and 4.3.3 + * on x86). Using a non-splitted version results in nicer looking code too. + * + * NOTE: This must return an int. Do not make it return a bool or the speed + * of the code generated by GCC 3.x decreases 10-15 %. (GCC 4.3 doesn't care, + * and it generates 10-20 % faster code than GCC 3.x from this file anyway.) + */ +static int rc_bit (struct rc_dec *rc, uint16_t *prob) { + + uint32_t bound; + int bit; + + rc_normalize (rc); + bound = (rc->range >> RC_BIT_MODEL_TOTAL_BITS) * *prob; + + if (rc->code < bound) { + + rc->range = bound; + + *prob += (RC_BIT_MODEL_TOTAL - *prob) >> RC_MOVE_BITS; + bit = 0; + + } else { + + rc->range -= bound; + rc->code -= bound; + + *prob -= *prob >> RC_MOVE_BITS; + bit = 1; + + } + + return bit; + +} + +/* Decode a bittree starting from the most significant bit. */ +static uint32_t rc_bittree (struct rc_dec *rc, uint16_t *probs, uint32_t limit) { + + uint32_t symbol = 1; + + do { + + if (rc_bit (rc, &probs[symbol])) { + symbol = (symbol << 1) + 1; + } else { + symbol <<= 1; + } + + } while (symbol < limit); + + return symbol; + +} + +/* Decode a bittree starting from the least significant bit. */ +static void rc_bittree_reverse (struct rc_dec *rc, uint16_t *probs, uint32_t *dest, uint32_t limit) { + + uint32_t symbol = 1; + uint32_t i = 0; + + do { + + if (rc_bit (rc, &probs[symbol])) { + + symbol = (symbol << 1) + 1; + *dest += 1 << i; + + } else { + symbol <<= 1; + } + + } while (++i < limit); + +} + +/* Decode direct bits (fixed fifty-fifty probability) */ +static void rc_direct (struct rc_dec *rc, uint32_t *dest, uint32_t limit) { + + uint32_t mask; + + do { + + rc_normalize(rc); + + rc->range >>= 1; + rc->code -= rc->range; + + mask = (uint32_t) 0 - (rc->code >> 31); + rc->code += rc->range & mask; + + *dest = (*dest << 1) + (mask + 1); + + } while (--limit > 0); + +} + +/* Get pointer to literal coder probability array. */ +static uint16_t *lzma_literal_probs (struct xz_dec_lzma2 *s) { + + uint32_t prev_byte = dict_get(&s->dict, 0); + + uint32_t low = prev_byte >> (8 - s->lzma.lc); + uint32_t high = (s->dict.pos & s->lzma.literal_pos_mask) << s->lzma.lc; + + return s->lzma.literal[low + high]; + +} + +/* Decode a literal (one 8-bit byte) */ +static void lzma_literal (struct xz_dec_lzma2 *s) { + + uint16_t *probs; + + uint32_t symbol, offset, i; + uint32_t match_byte, match_bit; + + probs = lzma_literal_probs (s); + + if (lzma_state_is_literal (s->lzma.state)) { + symbol = rc_bittree (&s->rc, probs, 0x100); + } else { + + symbol = 1; + + match_byte = dict_get (&s->dict, s->lzma.rep0) << 1; + offset = 0x100; + + do { + + match_bit = match_byte & offset; + match_byte <<= 1; + + i = offset + match_bit + symbol; + + if (rc_bit (&s->rc, &probs[i])) { + + symbol = (symbol << 1) + 1; + offset &= match_bit; + + } else { + + symbol <<= 1; + offset &= ~match_bit; + + } + + } while (symbol < 0x100); + + } + + dict_put (&s->dict, (uint8_t) symbol); + lzma_state_literal ((int *) &s->lzma.state); + +} + +/* Decode the length of the match into s->lzma.len. */ +static void lzma_len (struct xz_dec_lzma2 *s, struct lzma_len_dec *l, uint32_t pos_state) { + + uint16_t *probs; + uint32_t limit; + + if (!rc_bit (&s->rc, &l->choice)) { + + probs = l->low[pos_state]; + limit = LEN_LOW_SYMBOLS; + s->lzma.len = MATCH_LEN_MIN; + + } else { + + if (!rc_bit (&s->rc, &l->choice2)) { + + probs = l->mid[pos_state]; + limit = LEN_MID_SYMBOLS; + + s->lzma.len = MATCH_LEN_MIN + LEN_LOW_SYMBOLS; + + } else { + + probs = l->high; + limit = LEN_HIGH_SYMBOLS; + + s->lzma.len = MATCH_LEN_MIN + LEN_LOW_SYMBOLS + LEN_MID_SYMBOLS; + + } + + } + + s->lzma.len += rc_bittree (&s->rc, probs, limit) - limit; + +} + +/* Decode a match. The distance will be stored in s->lzma.rep0. */ +static void lzma_match (struct xz_dec_lzma2 *s, uint32_t pos_state) { + + uint32_t dist_slot, limit; + uint16_t *probs; + + lzma_state_match (&s->lzma.state); + + s->lzma.rep3 = s->lzma.rep2; + s->lzma.rep2 = s->lzma.rep1; + s->lzma.rep1 = s->lzma.rep0; + + lzma_len (s, &s->lzma.match_len_dec, pos_state); + + probs = s->lzma.dist_slot[lzma_get_dist_state (s->lzma.len)]; + dist_slot = rc_bittree (&s->rc, probs, DIST_SLOTS) - DIST_SLOTS; + + if (dist_slot < DIST_MODEL_START) { + s->lzma.rep0 = dist_slot; + } else { + + limit = (dist_slot >> 1) - 1; + s->lzma.rep0 = 2 + (dist_slot & 1); + + if (dist_slot < DIST_MODEL_END) { + + s->lzma.rep0 <<= limit; + + probs = s->lzma.dist_special + s->lzma.rep0 - dist_slot - 1; + rc_bittree_reverse (&s->rc, probs, &s->lzma.rep0, limit); + + } else { + + rc_direct (&s->rc, &s->lzma.rep0, limit - ALIGN_BITS); + + s->lzma.rep0 <<= ALIGN_BITS; + rc_bittree_reverse (&s->rc, s->lzma.dist_align, &s->lzma.rep0, ALIGN_BITS); + + } + + } + +} + +/** + * Decode a repeated match. The distance is one of the four most recently + * seen matches. The distance will be stored in s->lzma.rep0. + */ +static void lzma_rep_match (struct xz_dec_lzma2 *s, uint32_t pos_state) { + + uint32_t tmp; + + if (!rc_bit (&s->rc, &s->lzma.is_rep0[s->lzma.state])) { + + if (!rc_bit (&s->rc, &s->lzma.is_rep0_long[s->lzma.state][pos_state])) { + + lzma_state_short_rep (&s->lzma.state); + + s->lzma.len = 1; + return; + + } + + } else { + + if (!rc_bit (&s->rc, &s->lzma.is_rep1[s->lzma.state])) { + tmp = s->lzma.rep1; + } else { + + if (!rc_bit (&s->rc, &s->lzma.is_rep2[s->lzma.state])) { + tmp = s->lzma.rep2; + } else { + + tmp = s->lzma.rep3; + s->lzma.rep3 = s->lzma.rep2; + + } + + s->lzma.rep2 = s->lzma.rep1; + + } + + s->lzma.rep1 = s->lzma.rep0; + s->lzma.rep0 = tmp; + + } + + lzma_state_long_rep (&s->lzma.state); + lzma_len (s, &s->lzma.rep_len_dec, pos_state); + +} + +/* LZMA decoder core */ +static int lzma_main (struct xz_dec_lzma2 *s) { + + uint32_t pos_state; + + /* + * If the dictionary was reached during the previous call, try to + * finish the possibly pending repeat in the dictionary. + */ + if (dict_has_space (&s->dict) && s->lzma.len > 0) { + dict_repeat (&s->dict, &s->lzma.len, s->lzma.rep0); + } + + /* + * Decode more LZMA symbols. One iteration may consume up to + * LZMA_IN_REQUIRED - 1 bytes. + */ + while (dict_has_space (&s->dict) && !rc_limit_exceeded (&s->rc)) { + + pos_state = s->dict.pos & s->lzma.pos_mask; + + if (!rc_bit (&s->rc, &s->lzma.is_match[ + + s->lzma.state][pos_state])) { + lzma_literal (s); + + } else { + + if (rc_bit (&s->rc, &s->lzma.is_rep[s->lzma.state])) { + lzma_rep_match (s, pos_state); + } else { + lzma_match (s, pos_state); + } + + if (!dict_repeat (&s->dict, &s->lzma.len, s->lzma.rep0)) { + return 0; + } + + } + + } + + /* + * Having the range decoder always normalized when we are outside + * this function makes it easier to correctly handle end of the chunk. + */ + rc_normalize (&s->rc); + + /* Return */ + return 1; + +} + +/** + * Reset the LZMA decoder and range decoder state. Dictionary is nore reset + * here, because LZMA state may be reset without resetting the dictionary. + */ +static void lzma_reset (struct xz_dec_lzma2 *s) { + + uint16_t *probs; + uint64_t i; + + s->lzma.state = STATE_LIT_LIT; + s->lzma.rep0 = 0; + s->lzma.rep1 = 0; + s->lzma.rep2 = 0; + s->lzma.rep3 = 0; + + /* + * All probabilities are initialized to the same value. This hack + * makes the code smaller by avoiding a separate loop for each + * probability array. + * + * This could be optimized so that only that part of literal + * probabilities that are actually required. In the common case + * we would write 12 KiB less. + */ + probs = s->lzma.is_match[0]; + + for (i = 0; i < PROBS_TOTAL; ++i) { + probs[i] = RC_BIT_MODEL_TOTAL / 2; + } + + rc_reset (&s->rc); + +} + +/** + * Decode and validate LZMA properties (lc/lp/pb) and calculate the bit masks + * from the decoded lp and pb values. On success, the LZMA decoder state is + * reset and true is returned. + */ +static int lzma_props (struct xz_dec_lzma2 *s, uint8_t props) { + + if (props > (4 * 5 + 4) * 9 + 8) { + return 0; + } + + s->lzma.pos_mask = 0; + + while (props >= 9 * 5) { + + props -= 9 * 5; + ++s->lzma.pos_mask; + + } + + s->lzma.pos_mask = (1 << s->lzma.pos_mask) - 1; + s->lzma.literal_pos_mask = 0; + + while (props >= 9) { + + props -= 9; + ++s->lzma.literal_pos_mask; + + } + + s->lzma.lc = props; + + if (s->lzma.lc + s->lzma.literal_pos_mask > 4) { + return 0; + } + + s->lzma.literal_pos_mask = (1 << s->lzma.literal_pos_mask) - 1; + lzma_reset (s); + + return 1; + +} + +static void memzero (void *buf, uint64_t size) { + + uint8_t *b = buf; + uint8_t *e = b + size; + + while (b != e) { + *b++ = '\0'; + } + +} + +/* + * The LZMA decoder assumes that if the input limit (s->rc.in_limit) hasn't + * been exceeded, it is safe to read up to LZMA_IN_REQUIRED bytes. This + * wrapper function takes care of making the LZMA decoder's assumption safe. + * + * As long as there is plenty of input left to be decoded in the current LZMA + * chunk, we decode directly from the caller-supplied input buffer until + * there's LZMA_IN_REQUIRED bytes left. Those remaining bytes are copied into + * s->temp.buf, which (hopefully) gets filled on the next call to this + * function. We decode a few bytes from the temporary buffer so that we can + * continue decoding from the caller-supplied input buffer again. + */ +static int lzma2_lzma (struct xz_dec_lzma2 *s, struct xz_buf *b) { + + uint64_t in_avail; + uint32_t tmp; + + in_avail = b->in_size - b->in_pos; + + if (s->temp.size > 0 || s->lzma2.compressed == 0) { + + tmp = 2 * LZMA_IN_REQUIRED - s->temp.size; + + if (tmp > s->lzma2.compressed - s->temp.size) { + tmp = s->lzma2.compressed - s->temp.size; + } + + if (tmp > in_avail) { + tmp = in_avail; + } + + memcpy (s->temp.buf + s->temp.size, b->in + b->in_pos, tmp); + + if (s->temp.size + tmp == s->lzma2.compressed) { + + memzero (s->temp.buf + s->temp.size + tmp, sizeof (s->temp.buf) - s->temp.size - tmp); + s->rc.in_limit = s->temp.size + tmp; + + } else if (s->temp.size + tmp < LZMA_IN_REQUIRED) { + + s->temp.size += tmp; + b->in_pos += tmp; + + return 1; + + } else { + s->rc.in_limit = s->temp.size + tmp - LZMA_IN_REQUIRED; + } + + s->rc.in = s->temp.buf; + s->rc.in_pos = 0; + + if (!lzma_main (s) || s->rc.in_pos > s->temp.size + tmp) { + return 0; + } + + s->lzma2.compressed -= s->rc.in_pos; + + if (s->rc.in_pos < s->temp.size) { + + s->temp.size -= s->rc.in_pos; + + memmove (s->temp.buf, s->temp.buf + s->rc.in_pos, + s->temp.size); + + return 1; + + } + + b->in_pos += s->rc.in_pos - s->temp.size; + s->temp.size = 0; + + } + + in_avail = b->in_size - b->in_pos; + + if (in_avail >= LZMA_IN_REQUIRED) { + + s->rc.in = b->in; + s->rc.in_pos = b->in_pos; + + if (in_avail >= s->lzma2.compressed + LZMA_IN_REQUIRED) { + s->rc.in_limit = b->in_pos + s->lzma2.compressed; + } else { + s->rc.in_limit = b->in_size - LZMA_IN_REQUIRED; + } + + if (!lzma_main (s)) { + return 0; + } + + in_avail = s->rc.in_pos - b->in_pos; + + if (in_avail > s->lzma2.compressed) { + return 0; + } + + s->lzma2.compressed -= in_avail; + b->in_pos = s->rc.in_pos; + + } + + in_avail = b->in_size - b->in_pos; + + if (in_avail < LZMA_IN_REQUIRED) { + + if (in_avail > s->lzma2.compressed) { + in_avail = s->lzma2.compressed; + } + + memcpy (s->temp.buf, b->in + b->in_pos, in_avail); + s->temp.size = in_avail; + + b->in_pos += in_avail; + + } + + return 1; + +} + +/* + * Take care of the LZMA2 control layer, and forward the job of actual LZMA + * decoding or copying of uncompressed chunks to other functions. + */ +enum xz_ret xz_dec_lzma2_run (struct xz_dec_lzma2 *s, struct xz_buf *b) { + + uint32_t tmp; + + while (b->in_pos < b->in_size || s->lzma2.sequence == SEQ_LZMA_RUN) { + + switch (s->lzma2.sequence) { + + case SEQ_CONTROL: + + /* + * LZMA2 control byte + * + * Exact values: + * 0x00 End marker + * 0x01 Dictionary reset followed by + * an uncompressed chunk + * 0x02 Uncompressed chunk (no dictionary reset) + * + * Highest three bits (s->control & 0xE0): + * 0xE0 Dictionary reset, new properties and state + * reset, followed by LZMA compressed chunk + * 0xC0 New properties and state reset, followed + * by LZMA compressed chunk (no dictionary + * reset) + * 0xA0 State reset using old properties, + * followed by LZMA compressed chunk (no + * dictionary reset) + * 0x80 LZMA chunk (no dictionary or state reset) + * + * For LZMA compressed chunks, the lowest five bits + * (s->control & 1F) are the highest bits of the + * uncompressed size (bits 16-20). + * + * A new LZMA2 stream must begin with a dictionary + * reset. The first LZMA chunk must set new + * properties and reset the LZMA state. + * + * Values that don't match anything described above + * are invalid and we return XZ_DATA_ERROR. + */ + tmp = b->in[b->in_pos++]; + + if (tmp == 0x00) { + return XZ_STREAM_END; + } + + if (tmp >= 0xE0 || tmp == 0x01) { + + s->lzma2.need_props = 1; + s->lzma2.need_dict_reset = 0; + + dict_reset (&s->dict, b); + + } else if (s->lzma2.need_dict_reset) { + return XZ_DATA_ERROR; + } + + if (tmp >= 0x80) { + + s->lzma2.uncompressed = (tmp & 0x1F) << 16; + s->lzma2.sequence = SEQ_UNCOMPRESSED_1; + + if (tmp >= 0xC0) { + + /* + * When there are new properties, + * state reset is done at + * SEQ_PROPERTIES. + */ + s->lzma2.need_props = 0; + s->lzma2.next_sequence = SEQ_PROPERTIES; + + } else if (s->lzma2.need_props) { + return XZ_DATA_ERROR; + } else { + + s->lzma2.next_sequence = SEQ_LZMA_PREPARE; + + if (tmp >= 0xA0) { + lzma_reset (s); + } + + } + + } else { + + if (tmp > 0x02) { + return XZ_DATA_ERROR; + } + + s->lzma2.sequence = SEQ_COMPRESSED_0; + s->lzma2.next_sequence = SEQ_COPY; + + } + + break; + + case SEQ_UNCOMPRESSED_1: + + s->lzma2.uncompressed += (uint32_t )b->in[b->in_pos++] << 8; + s->lzma2.sequence = SEQ_UNCOMPRESSED_2; + break; + + case SEQ_UNCOMPRESSED_2: + + s->lzma2.uncompressed += (uint32_t) b->in[b->in_pos++] + 1; + s->lzma2.sequence = SEQ_COMPRESSED_0; + break; + + case SEQ_COMPRESSED_0: + + s->lzma2.compressed = (uint32_t) b->in[b->in_pos++] << 8; + s->lzma2.sequence = SEQ_COMPRESSED_1; + break; + + case SEQ_COMPRESSED_1: + + s->lzma2.compressed += (uint32_t) b->in[b->in_pos++] + 1; + s->lzma2.sequence = s->lzma2.next_sequence; + break; + + case SEQ_PROPERTIES: + + if (!lzma_props (s, b->in[b->in_pos++])) { + return XZ_DATA_ERROR; + } + + s->lzma2.sequence = SEQ_LZMA_PREPARE; + /* fall through */ + + case SEQ_LZMA_PREPARE: + + if (s->lzma2.compressed < RC_INIT_BYTES) { + return XZ_DATA_ERROR; + } + + if (!rc_read_init (&s->rc, b)) { + return XZ_OK; + } + + s->lzma2.compressed -= RC_INIT_BYTES; + s->lzma2.sequence = SEQ_LZMA_RUN; + + /* fall through */ + + case SEQ_LZMA_RUN: + + /* + * Set dictionary limit to indicate how much we want + * to be encoded at maximum. Decode new data into the + * dictionary. Flush the new data from dictionary to + * b->out. Check if we finished decoding this chunk. + * In case the dictionary got full but we didn't fill + * the output buffer yet, we may run this loop + * multiple times without changing s->lzma2.sequence. + */ + dict_limit (&s->dict, MIN (b->out_size - b->out_pos, s->lzma2.uncompressed)); + + if (!lzma2_lzma (s, b)) { + return XZ_DATA_ERROR; + } + + s->lzma2.uncompressed -= dict_flush (&s->dict, b); + + if (s->lzma2.uncompressed == 0) { + + if (s->lzma2.compressed > 0 || s->lzma.len > 0 || !rc_is_finished (&s->rc)) { + return XZ_DATA_ERROR; + } + + rc_reset (&s->rc); + s->lzma2.sequence = SEQ_CONTROL; + + } else if (b->out_pos == b->out_size || (b->in_pos == b->in_size && s->temp.size < s->lzma2.compressed)) { + return XZ_OK; + } + + break; + + case SEQ_COPY: + + dict_uncompressed (&s->dict, b, &s->lzma2.compressed); + + if (s->lzma2.compressed > 0) { + return XZ_OK; + } + + s->lzma2.sequence = SEQ_CONTROL; + break; + + } + + } + + return XZ_OK; + +} + +struct xz_dec_lzma2 *xz_dec_lzma2_create (enum xz_mode mode, uint32_t dict_max) { + + struct xz_dec_lzma2 *s; + + if (!(s = malloc (sizeof (*s)))) { + return 0; + } + + memzero (s, sizeof (*s)); + + s->dict.mode = mode; + s->dict.size_max = dict_max; + + if (DEC_IS_PREALLOC (mode)) { + + if (!(s->dict.buf = malloc (dict_max))) { + + free (s); + return 0; + + } + + memzero (s->dict.buf, sizeof (dict_max)); + + } else if (DEC_IS_DYNALLOC (mode)) { + + s->dict.buf = 0; + s->dict.allocated = 0; + + } + + return s; + +} + +enum xz_ret xz_dec_lzma2_reset (struct xz_dec_lzma2 *s, uint8_t props) { + + /* This limits dictionary size to 3 GiB to keep parsing simpler. */ + if (props > 39) { + return XZ_OPTIONS_ERROR; + } + + s->dict.size = 2 + (props & 1); + s->dict.size <<= (props >> 1) + 11; + + if (DEC_IS_MULTI (s->dict.mode)) { + + if (s->dict.size > s->dict.size_max) { + return XZ_MEMLIMIT_ERROR; + } + + s->dict.end = s->dict.size; + + if (DEC_IS_DYNALLOC (s->dict.mode)) { + + if (s->dict.allocated < s->dict.size) { + + free (s->dict.buf); + + if (!(s->dict.buf = malloc (s->dict.size))) { + + s->dict.allocated = 0; + return XZ_MEM_ERROR; + + } + + memzero (s->dict.buf, sizeof (s->dict.size)); + + } + + } + + } + + s->lzma.len = 0; + + s->lzma2.sequence = SEQ_CONTROL; + s->lzma2.need_dict_reset = 1; + + s->temp.size = 0; + return XZ_OK; + +} + +void xz_dec_lzma2_end (struct xz_dec_lzma2 *s) { + + if (DEC_IS_MULTI (s->dict.mode)) { + free (s->dict.buf); + } + + free (s); + +} diff --git a/libxz/xz_dec_stream.c b/libxz/xz_dec_stream.c new file mode 100644 index 0000000..38d025a --- /dev/null +++ b/libxz/xz_dec_stream.c @@ -0,0 +1,984 @@ +/****************************************************************************** + * @file xz_dec_stream.c + *****************************************************************************/ +#include +#include +#include +#include + +#include + +static uint32_t get_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); +} + +#define DEC_IS_SINGLE(mode) ((mode) == XZ_SINGLE) + +#ifndef MIN +# define MIN(x, y) ((x) < (y) ? (x) : (y)) +#endif + +/** + * Allocate memory for LZMA2 decoder. xz_dec_lzma2_reset() must be used + * before calling xz_dec_lzma2_run(). + */ +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. + */ +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. */ +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. */ +extern void xz_dec_lzma2_end (struct xz_dec_lzma2 *s); + +#define memeq(a, b, size) (memcmp (a, b, size) == 0) +#define memzero(buf, size) memset (buf, 0, size) + +/* Hash used to validate the Index field */ +struct xz_dec_hash { + + uint64_t unpadded, uncompressed; + uint64_t crc32; + +}; + +/* Integrity Check types */ +enum xz_check { + + XZ_CHECK_NONE = 0, + XZ_CHECK_CRC32 = 1, + XZ_CHECK_CRC64 = 4, + XZ_CHECK_SHA256 = 10 + +}; + +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() */ + uint64_t vli; + + /* Saved in_pos and out_pos */ + uint64_t in_start; + uint64_t out_start; + + /* CRC32 value in Block or Index */ + uint64_t crc; + + /* 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. + */ + int 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. + */ + uint64_t compressed; + + /* + * Value stored in the Uncompressed Size field, or + * VLI_UNKNOWN if Uncompressed Size is not present. + */ + uint64_t 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 */ + uint64_t compressed; + + /* Observed uncompressed size of the current Block */ + uint64_t uncompressed; + + /* Number of Blocks decoded so far */ + uint64_t 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 */ + uint64_t size; + + /* Number of Records (matches block.count in valid files) */ + uint64_t 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 uint64_t variables before it + * should guarantee this. + */ + struct { + + uint64_t pos; + uint64_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 + +}; + +/* + * 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 int fill_temp (struct xz_dec *s, struct xz_buf *b) { + + uint64_t copy_size = MIN (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 1; + + } + + return 0; + +} + +#define VLI_BYTES_MAX (sizeof (uint64_t) * 8 / 7) + +/* Decode a variable-length integer (little-endian base-128 encoding) */ +static enum xz_ret dec_vli (struct xz_dec *s, const uint8_t *in, uint64_t *in_pos, uint64_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 |= (uint64_t) (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 if presence of the CRC32 + * 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; + + 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); + } 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); + } + + if (ret == XZ_STREAM_END) { + + if (s->block_header.compressed != (uint64_t) -1 && s->block_header.compressed != s->block.compressed) { + return XZ_DATA_ERROR; + } + + if (s->block_header.uncompressed != (uint64_t) -1 && s->block_header.uncompressed != s->block.uncompressed) { + return XZ_DATA_ERROR; + } + + s->block.hash.unpadded += s->block_header.size + s->block.compressed; + + if (s->check_type == XZ_CHECK_CRC32) { + s->block.hash.unpadded += 4; + } else if (s->check_type == XZ_CHECK_CRC64) { + s->block.hash.unpadded += 8; + } + + 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) { + + uint64_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 input bytes match the value of s->crc32. + * s->pos must be zero when starting to validate the first byte. + */ +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; + +} + +#define HEADER_MAGIC "\3757zXZ" +#define HEADER_MAGIC_SIZE 6 + +/* 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 only none (Check ID = 0) and + * CRC32 (Check ID = 1). 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. + * 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]; + + if (s->check_type > XZ_CHECK_CRC32 && s->check_type != XZ_CHECK_CRC64) { + return XZ_OPTIONS_ERROR; + } + + return XZ_OK; + +} + +#define FOOTER_MAGIC "YZ" +#define FOOTER_MAGIC_SIZE 2 + +/* 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 = (uint64_t) -1; + } + + /* 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 = (uint64_t) -1; + } + +#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; + +} + +#define STREAM_HEADER_SIZE 12 + +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; + + for (;;) { + + 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; + } + + /* fall through */ + + 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; + + /* fall through */ + + 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; + /* fall through */ + + case SEQ_BLOCK_UNCOMPRESS: + + ret = dec_block (s, b); + + if (ret != XZ_STREAM_END) { + return ret; + } + + s->sequence = SEQ_BLOCK_PADDING; + /* fall through */ + + 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; + /* fall through */ + + 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 (s->check_type == XZ_CHECK_CRC64) { + + 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; + /* fall through */ + + 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; + /* fall through */ + + 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; + + /* fall through */ + + 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). + */ +enum xz_ret xz_dec_run (struct xz_dec *s, struct xz_buf *b) { + + uint64_t in_start; + uint64_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 = 1; + + } else { + s->allow_buf_error = 0; + } + + return ret; + +} + +struct xz_dec *xz_dec_init (enum xz_mode mode, uint32_t dict_max) { + + struct xz_dec *s; + + if (!(s = malloc (sizeof (*s)))) { + return 0; + } + + memzero (s, sizeof (*s)); + 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 + + if (!(s->lzma2 = xz_dec_lzma2_create (mode, dict_max))) { + goto error_lzma2; + } + + xz_dec_reset (s); + return s; + +error_lzma2: + +#ifdef XZ_DEC_BCJ + xz_dec_bcj_end(s->bcj); + error_bcj: +#endif + + free (s); + return 0; + +} + +void xz_dec_reset (struct xz_dec *s) { + + s->sequence = SEQ_STREAM_HEADER; + s->allow_buf_error = 0; + + 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; + +} + +void xz_dec_end (struct xz_dec *s) { + + if (s) { + + xz_dec_lzma2_end (s->lzma2); +#ifdef XZ_DEC_BCJ + xz_dec_bcj_end (s->bcj); +#endif + + free (s); + + } + +} diff --git a/report.c b/report.c new file mode 100644 index 0000000..8e128ef --- /dev/null +++ b/report.c @@ -0,0 +1,150 @@ +/****************************************************************************** + * @file report.c + *****************************************************************************/ +#include +#include +#include + +#include "report.h" + +unsigned long errors = 0; + +#ifndef __PDOS__ +#if defined (_WIN32) +# include +static int OriginalConsoleColor = -1; +#endif + +static void reset_console_color (void) { + +#if defined (_WIN32) + + HANDLE hStdError = GetStdHandle (STD_ERROR_HANDLE); + + if (OriginalConsoleColor == -1) { return; } + + SetConsoleTextAttribute (hStdError, OriginalConsoleColor); + OriginalConsoleColor = -1; + +#else + + fprintf (stderr, "\033[0m"); + +#endif + +} + +static void set_console_color (int color) { + +#if defined (_WIN32) + + HANDLE hStdError = GetStdHandle (STD_ERROR_HANDLE); + WORD wColor; + + if (OriginalConsoleColor == -1) { + + CONSOLE_SCREEN_BUFFER_INFO csbi; + + if (!GetConsoleScreenBufferInfo (hStdError, &csbi)) { + return; + } + + OriginalConsoleColor = csbi.wAttributes; + + } + + wColor = (OriginalConsoleColor & 0xF0) + (color & 0xF); + SetConsoleTextAttribute (hStdError, wColor); + +#else + + fprintf (stderr, "\033[%dm", color); + +#endif + +} +#endif + +static void output_message (const char *filename, unsigned long lineno, unsigned long idx, enum report_type type, const char *fmt, va_list ap) { + + if (filename) { + + if (lineno == 0 && idx == 0) { + fprintf (stderr, "%s: ", filename); + } else { + fprintf (stderr, "%s:", filename); + } + + } + + if (lineno > 0) { + + if (idx == 0) { + fprintf (stderr, "%lu: ", lineno); + } else { + fprintf (stderr, "%lu:", lineno); + } + + } + + if (idx > 0) { + fprintf (stderr, "%lu: ", idx); + } + + if (type == REPORT_ERROR || type == REPORT_FATAL_ERROR) { + +#ifndef __PDOS__ + set_console_color (COLOR_ERROR); +#endif + + if (type == REPORT_ERROR) { + fprintf (stderr, "error:"); + } else { + fprintf (stderr, "fatal error:"); + } + + } else if (type == REPORT_INTERNAL_ERROR) { + +#ifndef __PDOS__ + set_console_color (COLOR_INTERNAL_ERROR); +#endif + + fprintf (stderr, "internal error:"); + + } else if (type == REPORT_WARNING) { + +#ifndef __PDOS__ + set_console_color (COLOR_WARNING); +#endif + + fprintf (stderr, "warning:"); + + } + +#ifndef __PDOS__ + reset_console_color (); +#endif + + fprintf (stderr, " "); + vfprintf (stderr, fmt, ap); + fprintf (stderr, "\n"); + + if (type != REPORT_WARNING) { + ++errors; + } + +} + +unsigned long get_error_count (void) { + return errors; +} + +void report_at (const char *filename, unsigned long lineno, enum report_type type, const char *fmt, ...) { + + va_list ap; + + va_start (ap, fmt); + output_message (filename, lineno, 0, type, fmt, ap); + va_end (ap); + +} diff --git a/report.h b/report.h new file mode 100644 index 0000000..8fc8758 --- /dev/null +++ b/report.h @@ -0,0 +1,29 @@ +/****************************************************************************** + * @file report.h + *****************************************************************************/ +#ifndef _REPORT_H +#define _REPORT_H + +enum report_type { + + REPORT_ERROR = 0, + REPORT_FATAL_ERROR, + REPORT_INTERNAL_ERROR, + REPORT_WARNING + +}; + +#if defined (_WIN32) +# define COLOR_ERROR 12 +# define COLOR_WARNING 13 +# define COLOR_INTERNAL_ERROR 19 +#else +# define COLOR_ERROR 91 +# define COLOR_INTERNAL_ERROR 94 +# define COLOR_WARNING 95 +#endif + +unsigned long get_error_count (void); +void report_at (const char *filename, unsigned long line_number, enum report_type type, const char *fmt, ...); + +#endif /* _REPORT_H */ diff --git a/unxz.c b/unxz.c new file mode 100644 index 0000000..47d1b1e --- /dev/null +++ b/unxz.c @@ -0,0 +1,179 @@ +/****************************************************************************** + * @file unxz.c + *****************************************************************************/ +#include +#include +#include +#include + +#include +#include "lib.h" +#include "report.h" +#include "unxz.h" + +#define XZ_IOBUF_SIZE 4096 + +struct unxz_state *state = 0; +const char *program_name = 0; + +int main (int argc, char **argv) { + + struct xz_buf b = { 0 }; + struct xz_dec *s; + + enum xz_ret ret; + int i; + + FILE *ifp, *ofp; + + const char *ipath; + char *opath = 0, *p; + + if (argc && *argv) { + + program_name = *argv; + + if ((p = strrchr (program_name, '/')) || (p == strrchr (program_name, '\\'))) { + program_name = (p + 1); + } + + } + + state = xmalloc (sizeof (*state)); + parse_args (argc, argv, 1); + + if (state->nb_files == 0) { + + report_at (program_name, 0, REPORT_ERROR, "no input files provided"); + return EXIT_FAILURE; + + } + + xz_crc32_init (); + xz_crc64_init (); + + if (!(s = xz_dec_init (XZ_DYNALLOC, (uint32_t) -1))) { + return -1; + } + + b.out_size = XZ_IOBUF_SIZE; + + if (!(b.out = malloc (b.out_size))) { + return -1; + } + + if (!(b.in = malloc (XZ_IOBUF_SIZE))) { + return -1; + } + + for (i = 0; i < state->nb_files; i++) { + + b.out_pos = 0; + + b.in_pos = 0; + b.in_size = 0; + + ipath = state->files[i]; + + if (!(ifp = fopen (ipath, "r+b"))) { + + report_at (program_name, 0, REPORT_ERROR, "failed to open '%s' for reading", ipath); + continue; + + } + + if ((p = strrchr (ipath, '.'))) { + + if (strcmp (p, ".xz")) { + + report_at (program_name, 0, REPORT_ERROR, "skipping %s", ipath); + + fclose (ifp); + continue; + + } + + opath = xstrndup (ipath, p - ipath); + + } + + if (!(ofp = fopen (opath, "w+b"))) { + + report_at (program_name, 0, REPORT_ERROR, "failed to open '%s' for writing", opath); + free (opath); + + fclose (ifp); + continue; + + } + + do { + + if (b.in_pos == b.in_size) { + + b.in_size = fread (b.in, 1, XZ_IOBUF_SIZE, ifp); + b.in_pos = 0; + + } + + ret = xz_dec_run (s, &b); + + if (b.out_pos == b.out_size || (ret != XZ_OK && b.out_pos > 0)) { + + if (fwrite (b.out, 1, b.out_pos, ofp) != (uint64_t) b.out_pos) { + ret = XZ_BUF_ERROR; + } + + b.out_pos = 0; + + } + + } while (ret == XZ_OK); + + switch (ret) { + + case XZ_STREAM_END: + + break; + + case XZ_MEM_ERROR: + + /* This can occur only in multi-call mode. */ + report_at (program_name, 0, REPORT_ERROR, "XZ decompressor ran out of memory\n"); + break; + + case XZ_FORMAT_ERROR: + + report_at (program_name, 0, REPORT_ERROR, "Input is not in the XZ format (wrong magic bytes)\n"); + break; + + case XZ_OPTIONS_ERROR: + + report_at (program_name, 0, REPORT_ERROR, "Input was encoded with settings that are not supported by this XZ decoder\n"); + break; + + case XZ_DATA_ERROR: case XZ_BUF_ERROR: + + report_at (program_name, 0, REPORT_ERROR, "XZ-compressed data is corrupt\n"); + break; + + default: + + report_at (program_name, 0, REPORT_INTERNAL_ERROR, "Bug in the XZ decompressor\n"); + break; + + } + + fclose (ifp); + fclose (ofp); + + free (opath); + + } + + xz_dec_end (s); + free (b.in); + + return (get_error_count () ? EXIT_FAILURE : EXIT_SUCCESS); + +} diff --git a/unxz.h b/unxz.h new file mode 100755 index 0000000..05b2102 --- /dev/null +++ b/unxz.h @@ -0,0 +1,17 @@ +/****************************************************************************** + * @file unxz.h + *****************************************************************************/ +#ifndef _UNXZ_H +#define _UNXZ_H + +struct unxz_state { + + const char **files; + long nb_files; + +}; + +extern struct unxz_state *state; +extern const char *program_name; + +#endif /* _UNXZ_H */ -- 2.34.1