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2bbdda09df
busybox/archival/libunarchive/decompress_unlzma.c
Denis Vlasenko 2bbdda09df unlzma: fix memory leak (Pascal Bellard)
2008-06-27 15:48:45 +00:00

504 lines
13 KiB
C
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/* vi: set sw=4 ts=4: */
/*
* Small lzma deflate implementation.
* Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
*
* Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
* Copyright (C) 1999-2005 Igor Pavlov
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
#if ENABLE_FEATURE_LZMA_FAST
# define speed_inline ALWAYS_INLINE
#else
# define speed_inline
#endif
typedef struct {
int fd;
uint8_t *ptr;
/* Was keeping rc on stack in unlzma and separately allocating buffer,
* but with "buffer 'attached to' allocated rc" code is smaller: */
/* uint8_t *buffer; */
#define RC_BUFFER ((uint8_t*)(rc+1))
uint8_t *buffer_end;
/* Had provisions for variable buffer, but we don't need it here */
/* int buffer_size; */
#define RC_BUFFER_SIZE 0x10000
uint32_t code;
uint32_t range;
uint32_t bound;
} rc_t;
#define RC_TOP_BITS 24
#define RC_MOVE_BITS 5
#define RC_MODEL_TOTAL_BITS 11
/* Called twice: once at startup and once in rc_normalize() */
static void rc_read(rc_t *rc)
{
int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
if (buffer_size <= 0)
bb_error_msg_and_die("unexpected EOF");
rc->ptr = RC_BUFFER;
rc->buffer_end = RC_BUFFER + buffer_size;
}
/* Called once */
static rc_t* rc_init(int fd) /*, int buffer_size) */
{
int i;
rc_t *rc;
rc = xmalloc(sizeof(*rc) + RC_BUFFER_SIZE);
rc->fd = fd;
/* rc->buffer_size = buffer_size; */
rc->buffer_end = RC_BUFFER + RC_BUFFER_SIZE;
rc->ptr = rc->buffer_end;
rc->code = 0;
rc->range = 0xFFFFFFFF;
for (i = 0; i < 5; i++) {
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->code = (rc->code << 8) | *rc->ptr++;
}
return rc;
}
/* Called once */
static ALWAYS_INLINE void rc_free(rc_t *rc)
{
free(rc);
}
/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
static void rc_do_normalize(rc_t *rc)
{
if (rc->ptr >= rc->buffer_end)
rc_read(rc);
rc->range <<= 8;
rc->code = (rc->code << 8) | *rc->ptr++;
}
static ALWAYS_INLINE void rc_normalize(rc_t *rc)
{
if (rc->range < (1 << RC_TOP_BITS)) {
rc_do_normalize(rc);
}
}
/* rc_is_bit_0 is called 9 times */
/* Why rc_is_bit_0_helper exists?
* Because we want to always expose (rc->code < rc->bound) to optimizer.
* Thus rc_is_bit_0 is always inlined, and rc_is_bit_0_helper is inlined
* only if we compile for speed.
*/
static speed_inline uint32_t rc_is_bit_0_helper(rc_t *rc, uint16_t *p)
{
rc_normalize(rc);
rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
return rc->bound;
}
static ALWAYS_INLINE int rc_is_bit_0(rc_t *rc, uint16_t *p)
{
uint32_t t = rc_is_bit_0_helper(rc, p);
return rc->code < t;
}
/* Called ~10 times, but very small, thus inlined */
static speed_inline void rc_update_bit_0(rc_t *rc, uint16_t *p)
{
rc->range = rc->bound;
*p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
}
static speed_inline void rc_update_bit_1(rc_t *rc, uint16_t *p)
{
rc->range -= rc->bound;
rc->code -= rc->bound;
*p -= *p >> RC_MOVE_BITS;
}
/* Called 4 times in unlzma loop */
static int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol)
{
if (rc_is_bit_0(rc, p)) {
rc_update_bit_0(rc, p);
*symbol *= 2;
return 0;
} else {
rc_update_bit_1(rc, p);
*symbol = *symbol * 2 + 1;
return 1;
}
}
/* Called once */
static ALWAYS_INLINE int rc_direct_bit(rc_t *rc)
{
rc_normalize(rc);
rc->range >>= 1;
if (rc->code >= rc->range) {
rc->code -= rc->range;
return 1;
}
return 0;
}
/* Called twice */
static speed_inline void
rc_bit_tree_decode(rc_t *rc, uint16_t *p, int num_levels, int *symbol)
{
int i = num_levels;
*symbol = 1;
while (i--)
rc_get_bit(rc, p + *symbol, symbol);
*symbol -= 1 << num_levels;
}
typedef struct {
uint8_t pos;
uint32_t dict_size;
uint64_t dst_size;
} __attribute__ ((packed)) lzma_header_t;
/* #defines will force compiler to compute/optimize each one with each usage.
* Have heart and use enum instead. */
enum {
LZMA_BASE_SIZE = 1846,
LZMA_LIT_SIZE = 768,
LZMA_NUM_POS_BITS_MAX = 4,
LZMA_LEN_NUM_LOW_BITS = 3,
LZMA_LEN_NUM_MID_BITS = 3,
LZMA_LEN_NUM_HIGH_BITS = 8,
LZMA_LEN_CHOICE = 0,
LZMA_LEN_CHOICE_2 = (LZMA_LEN_CHOICE + 1),
LZMA_LEN_LOW = (LZMA_LEN_CHOICE_2 + 1),
LZMA_LEN_MID = (LZMA_LEN_LOW \
+ (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))),
LZMA_LEN_HIGH = (LZMA_LEN_MID \
+ (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))),
LZMA_NUM_LEN_PROBS = (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)),
LZMA_NUM_STATES = 12,
LZMA_NUM_LIT_STATES = 7,
LZMA_START_POS_MODEL_INDEX = 4,
LZMA_END_POS_MODEL_INDEX = 14,
LZMA_NUM_FULL_DISTANCES = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),
LZMA_NUM_POS_SLOT_BITS = 6,
LZMA_NUM_LEN_TO_POS_STATES = 4,
LZMA_NUM_ALIGN_BITS = 4,
LZMA_MATCH_MIN_LEN = 2,
LZMA_IS_MATCH = 0,
LZMA_IS_REP = (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
LZMA_IS_REP_G0 = (LZMA_IS_REP + LZMA_NUM_STATES),
LZMA_IS_REP_G1 = (LZMA_IS_REP_G0 + LZMA_NUM_STATES),
LZMA_IS_REP_G2 = (LZMA_IS_REP_G1 + LZMA_NUM_STATES),
LZMA_IS_REP_0_LONG = (LZMA_IS_REP_G2 + LZMA_NUM_STATES),
LZMA_POS_SLOT = (LZMA_IS_REP_0_LONG \
+ (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
LZMA_SPEC_POS = (LZMA_POS_SLOT \
+ (LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)),
LZMA_ALIGN = (LZMA_SPEC_POS \
+ LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX),
LZMA_LEN_CODER = (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)),
LZMA_REP_LEN_CODER = (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS),
LZMA_LITERAL = (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS),
};
USE_DESKTOP(long long) int FAST_FUNC
unpack_lzma_stream(int src_fd, int dst_fd)
{
USE_DESKTOP(long long total_written = 0;)
lzma_header_t header;
int lc, pb, lp;
uint32_t pos_state_mask;
uint32_t literal_pos_mask;
uint32_t pos;
uint16_t *p;
uint16_t *prob;
uint16_t *prob_lit;
int num_bits;
int num_probs;
rc_t *rc;
int i, mi;
uint8_t *buffer;
uint8_t previous_byte = 0;
size_t buffer_pos = 0, global_pos = 0;
int len = 0;
int state = 0;
uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
xread(src_fd, &header, sizeof(header));
if (header.pos >= (9 * 5 * 5))
bb_error_msg_and_die("bad header");
mi = header.pos / 9;
lc = header.pos % 9;
pb = mi / 5;
lp = mi % 5;
pos_state_mask = (1 << pb) - 1;
literal_pos_mask = (1 << lp) - 1;
header.dict_size = SWAP_LE32(header.dict_size);
header.dst_size = SWAP_LE64(header.dst_size);
if (header.dict_size == 0)
header.dict_size = 1;
buffer = xmalloc(MIN(header.dst_size, header.dict_size));
num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
p = xmalloc(num_probs * sizeof(*p));
num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
for (i = 0; i < num_probs; i++)
p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
rc = rc_init(src_fd); /*, RC_BUFFER_SIZE); */
while (global_pos + buffer_pos < header.dst_size) {
int pos_state = (buffer_pos + global_pos) & pos_state_mask;
prob = p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
if (rc_is_bit_0(rc, prob)) {
mi = 1;
rc_update_bit_0(rc, prob);
prob = (p + LZMA_LITERAL
+ (LZMA_LIT_SIZE * ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
+ (previous_byte >> (8 - lc))
)
)
);
if (state >= LZMA_NUM_LIT_STATES) {
int match_byte;
pos = buffer_pos - rep0;
while (pos >= header.dict_size)
pos += header.dict_size;
match_byte = buffer[pos];
do {
int bit;
match_byte <<= 1;
bit = match_byte & 0x100;
prob_lit = prob + 0x100 + bit + mi;
bit ^= (rc_get_bit(rc, prob_lit, &mi) << 8); /* 0x100 or 0 */
if (bit)
break;
} while (mi < 0x100);
}
while (mi < 0x100) {
prob_lit = prob + mi;
rc_get_bit(rc, prob_lit, &mi);
}
state -= 3;
if (state < 4-3)
state = 0;
if (state >= 10-3)
state -= 6-3;
previous_byte = (uint8_t) mi;
#if ENABLE_FEATURE_LZMA_FAST
one_byte1:
buffer[buffer_pos++] = previous_byte;
if (buffer_pos == header.dict_size) {
buffer_pos = 0;
global_pos += header.dict_size;
if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
goto bad;
USE_DESKTOP(total_written += header.dict_size;)
}
#else
len = 1;
goto one_byte2;
#endif
} else {
int offset;
uint16_t *prob_len;
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
rep3 = rep2;
rep2 = rep1;
rep1 = rep0;
state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
prob = p + LZMA_LEN_CODER;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G0 + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
prob = (p + LZMA_IS_REP_0_LONG
+ (state << LZMA_NUM_POS_BITS_MAX)
+ pos_state
);
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
#if ENABLE_FEATURE_LZMA_FAST
pos = buffer_pos - rep0;
while (pos >= header.dict_size)
pos += header.dict_size;
previous_byte = buffer[pos];
goto one_byte1;
#else
len = 1;
goto string;
#endif
} else {
rc_update_bit_1(rc, prob);
}
} else {
uint32_t distance;
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G1 + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = rep1;
} else {
rc_update_bit_1(rc, prob);
prob = p + LZMA_IS_REP_G2 + state;
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = rep2;
} else {
rc_update_bit_1(rc, prob);
distance = rep3;
rep3 = rep2;
}
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
prob = p + LZMA_REP_LEN_CODER;
}
prob_len = prob + LZMA_LEN_CHOICE;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_LOW
+ (pos_state << LZMA_LEN_NUM_LOW_BITS));
offset = 0;
num_bits = LZMA_LEN_NUM_LOW_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_CHOICE_2;
if (rc_is_bit_0(rc, prob_len)) {
rc_update_bit_0(rc, prob_len);
prob_len = (prob + LZMA_LEN_MID
+ (pos_state << LZMA_LEN_NUM_MID_BITS));
offset = 1 << LZMA_LEN_NUM_LOW_BITS;
num_bits = LZMA_LEN_NUM_MID_BITS;
} else {
rc_update_bit_1(rc, prob_len);
prob_len = prob + LZMA_LEN_HIGH;
offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
+ (1 << LZMA_LEN_NUM_MID_BITS));
num_bits = LZMA_LEN_NUM_HIGH_BITS;
}
}
rc_bit_tree_decode(rc, prob_len, num_bits, &len);
len += offset;
if (state < 4) {
int pos_slot;
state += LZMA_NUM_LIT_STATES;
prob = p + LZMA_POS_SLOT +
((len < LZMA_NUM_LEN_TO_POS_STATES ? len :
LZMA_NUM_LEN_TO_POS_STATES - 1)
<< LZMA_NUM_POS_SLOT_BITS);
rc_bit_tree_decode(rc, prob, LZMA_NUM_POS_SLOT_BITS,
&pos_slot);
if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
num_bits = (pos_slot >> 1) - 1;
rep0 = 2 | (pos_slot & 1);
if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
rep0 <<= num_bits;
prob = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
} else {
num_bits -= LZMA_NUM_ALIGN_BITS;
while (num_bits--)
rep0 = (rep0 << 1) | rc_direct_bit(rc);
prob = p + LZMA_ALIGN;
rep0 <<= LZMA_NUM_ALIGN_BITS;
num_bits = LZMA_NUM_ALIGN_BITS;
}
i = 1;
mi = 1;
while (num_bits--) {
if (rc_get_bit(rc, prob + mi, &mi))
rep0 |= i;
i <<= 1;
}
} else
rep0 = pos_slot;
if (++rep0 == 0)
break;
}
len += LZMA_MATCH_MIN_LEN;
SKIP_FEATURE_LZMA_FAST(string:)
do {
pos = buffer_pos - rep0;
while (pos >= header.dict_size)
pos += header.dict_size;
previous_byte = buffer[pos];
SKIP_FEATURE_LZMA_FAST(one_byte2:)
buffer[buffer_pos++] = previous_byte;
if (buffer_pos == header.dict_size) {
buffer_pos = 0;
global_pos += header.dict_size;
if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
goto bad;
USE_DESKTOP(total_written += header.dict_size;)
}
len--;
} while (len != 0 && buffer_pos < header.dst_size);
}
}
{
SKIP_DESKTOP(int total_written = 0; /* success */)
USE_DESKTOP(total_written += buffer_pos;)
if (full_write(dst_fd, buffer, buffer_pos) != (ssize_t)buffer_pos) {
bad:
total_written = -1; /* failure */
}
rc_free(rc);
free(p);
free(buffer);
return total_written;
}
}
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