/* Lzma decompressor for Linux kernel. Shamelessly snarfed *from busybox 1.1.1 * *Linux kernel adaptation *Copyright (C) 2006 Alain < alain@knaff.lu > * *Based on small lzma deflate implementation/Small range coder *implementation for lzma. *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 * *Copyrights of the parts, see headers below. * * *This program is free software; you can redistribute it and/or *modify it under the terms of the GNU Lesser General Public *License as published by the Free Software Foundation; either *version 2.1 of the License, or (at your option) any later version. * *This program is distributed in the hope that it will be useful, *but WITHOUT ANY WARRANTY; without even the implied warranty of *MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *Lesser General Public License for more details. * *You should have received a copy of the GNU Lesser General Public *License along with this library; if not, write to the Free Software *Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef STATIC #include <linux/decompress/unlzma.h> #endif /* STATIC */ #include <linux/decompress/mm.h> #include <linux/slab.h> #define MIN(a, b) (((a) < (b)) ? (a) : (b)) static long long INIT read_int(unsigned char *ptr, int size) { int i; long long ret = 0; for (i = 0; i < size; i++) ret = (ret << 8) | ptr[size-i-1]; return ret; } #define ENDIAN_CONVERT(x) \ x = (typeof(x))read_int((unsigned char *)&x, sizeof(x)) /* Small range coder implementation for lzma. *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 */ #include <linux/compiler.h> #define LZMA_IOBUF_SIZE 0x10000 struct rc { int (*fill)(void*, unsigned int); uint8_t *ptr; uint8_t *buffer; uint8_t *buffer_end; int buffer_size; uint32_t code; uint32_t range; uint32_t bound; }; #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 INIT rc_read(struct rc *rc) { rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE); if (rc->buffer_size <= 0) error("unexpected EOF"); rc->ptr = rc->buffer; rc->buffer_end = rc->buffer + rc->buffer_size; } /* Called once */ static inline void INIT rc_init(struct rc *rc, int (*fill)(void*, unsigned int), char *buffer, int buffer_size) { rc->fill = fill; rc->buffer = (uint8_t *)buffer; rc->buffer_size = buffer_size; rc->buffer_end = rc->buffer + rc->buffer_size; rc->ptr = rc->buffer; rc->code = 0; rc->range = 0xFFFFFFFF; } static inline void INIT rc_init_code(struct rc *rc) { int i; for (i = 0; i < 5; i++) { if (rc->ptr >= rc->buffer_end) rc_read(rc); rc->code = (rc->code << 8) | *rc->ptr++; } } /* Called once. TODO: bb_maybe_free() */ static inline void INIT rc_free(struct rc *rc) { free(rc->buffer); } /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */ static void INIT rc_do_normalize(struct rc *rc) { if (rc->ptr >= rc->buffer_end) rc_read(rc); rc->range <<= 8; rc->code = (rc->code << 8) | *rc->ptr++; } static inline void INIT rc_normalize(struct rc *rc) { if (rc->range < (1 << RC_TOP_BITS)) rc_do_normalize(rc); } /* Called 9 times */ /* Why rc_is_bit_0_helper exists? *Because we want to always expose (rc->code < rc->bound) to optimizer */ static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p) { rc_normalize(rc); rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS); return rc->bound; } static inline int INIT rc_is_bit_0(struct rc *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 inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p) { rc->range = rc->bound; *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS; } static inline void rc_update_bit_1(struct rc *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 INIT rc_get_bit(struct rc *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 inline int INIT rc_direct_bit(struct rc *rc) { rc_normalize(rc); rc->range >>= 1; if (rc->code >= rc->range) { rc->code -= rc->range; return 1; } return 0; } /* Called twice */ static inline void INIT rc_bit_tree_decode(struct rc *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; } /* * 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 */ struct lzma_header { uint8_t pos; uint32_t dict_size; uint64_t dst_size; } __attribute__ ((packed)) ; #define LZMA_BASE_SIZE 1846 #define LZMA_LIT_SIZE 768 #define LZMA_NUM_POS_BITS_MAX 4 #define LZMA_LEN_NUM_LOW_BITS 3 #define LZMA_LEN_NUM_MID_BITS 3 #define LZMA_LEN_NUM_HIGH_BITS 8 #define LZMA_LEN_CHOICE 0 #define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1) #define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1) #define LZMA_LEN_MID (LZMA_LEN_LOW \ + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))) #define LZMA_LEN_HIGH (LZMA_LEN_MID \ +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))) #define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)) #define LZMA_NUM_STATES 12 #define LZMA_NUM_LIT_STATES 7 #define LZMA_START_POS_MODEL_INDEX 4 #define LZMA_END_POS_MODEL_INDEX 14 #define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1)) #define LZMA_NUM_POS_SLOT_BITS 6 #define LZMA_NUM_LEN_TO_POS_STATES 4 #define LZMA_NUM_ALIGN_BITS 4 #define LZMA_MATCH_MIN_LEN 2 #define LZMA_IS_MATCH 0 #define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)) #define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES) #define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES) #define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES) #define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES) #define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \ + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)) #define LZMA_SPEC_POS (LZMA_POS_SLOT \ +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)) #define LZMA_ALIGN (LZMA_SPEC_POS \ + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX) #define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)) #define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS) #define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS) struct writer { uint8_t *buffer; uint8_t previous_byte; size_t buffer_pos; int bufsize; size_t global_pos; int(*flush)(void*, unsigned int); struct lzma_header *header; }; struct cstate { int state; uint32_t rep0, rep1, rep2, rep3; }; static inline size_t INIT get_pos(struct writer *wr) { return wr->global_pos + wr->buffer_pos; } static inline uint8_t INIT peek_old_byte(struct writer *wr, uint32_t offs) { if (!wr->flush) { int32_t pos; while (offs > wr->header->dict_size) offs -= wr->header->dict_size; pos = wr->buffer_pos - offs; return wr->buffer[pos]; } else { uint32_t pos = wr->buffer_pos - offs; while (pos >= wr->header->dict_size) pos += wr->header->dict_size; return wr->buffer[pos]; } } static inline void INIT write_byte(struct writer *wr, uint8_t byte) { wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte; if (wr->flush && wr->buffer_pos == wr->header->dict_size) { wr->buffer_pos = 0; wr->global_pos += wr->header->dict_size; wr->flush((char *)wr->buffer, wr->header->dict_size); } } static inline void INIT copy_byte(struct writer *wr, uint32_t offs) { write_byte(wr, peek_old_byte(wr, offs)); } static inline void INIT copy_bytes(struct writer *wr, uint32_t rep0, int len) { do { copy_byte(wr, rep0); len--; } while (len != 0 && wr->buffer_pos < wr->header->dst_size); } static inline void INIT process_bit0(struct writer *wr, struct rc *rc, struct cstate *cst, uint16_t *p, int pos_state, uint16_t *prob, int lc, uint32_t literal_pos_mask) { int mi = 1; rc_update_bit_0(rc, prob); prob = (p + LZMA_LITERAL + (LZMA_LIT_SIZE * (((get_pos(wr) & literal_pos_mask) << lc) + (wr->previous_byte >> (8 - lc)))) ); if (cst->state >= LZMA_NUM_LIT_STATES) { int match_byte = peek_old_byte(wr, cst->rep0); do { int bit; uint16_t *prob_lit; match_byte <<= 1; bit = match_byte & 0x100; prob_lit = prob + 0x100 + bit + mi; if (rc_get_bit(rc, prob_lit, &mi)) { if (!bit) break; } else { if (bit) break; } } while (mi < 0x100); } while (mi < 0x100) { uint16_t *prob_lit = prob + mi; rc_get_bit(rc, prob_lit, &mi); } write_byte(wr, mi); if (cst->state < 4) cst->state = 0; else if (cst->state < 10) cst->state -= 3; else cst->state -= 6; } static inline void INIT process_bit1(struct writer *wr, struct rc *rc, struct cstate *cst, uint16_t *p, int pos_state, uint16_t *prob) { int offset; uint16_t *prob_len; int num_bits; int len; rc_update_bit_1(rc, prob); prob = p + LZMA_IS_REP + cst->state; if (rc_is_bit_0(rc, prob)) { rc_update_bit_0(rc, prob); cst->rep3 = cst->rep2; cst->rep2 = cst->rep1; cst->rep1 = cst->rep0; cst->state = cst->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 + cst->state; if (rc_is_bit_0(rc, prob)) { rc_update_bit_0(rc, prob); prob = (p + LZMA_IS_REP_0_LONG + (cst->state << LZMA_NUM_POS_BITS_MAX) + pos_state); if (rc_is_bit_0(rc, prob)) { rc_update_bit_0(rc, prob); cst->state = cst->state < LZMA_NUM_LIT_STATES ? 9 : 11; copy_byte(wr, cst->rep0); return; } else { rc_update_bit_1(rc, prob); } } else { uint32_t distance; rc_update_bit_1(rc, prob); prob = p + LZMA_IS_REP_G1 + cst->state; if (rc_is_bit_0(rc, prob)) { rc_update_bit_0(rc, prob); distance = cst->rep1; } else { rc_update_bit_1(rc, prob); prob = p + LZMA_IS_REP_G2 + cst->state; if (rc_is_bit_0(rc, prob)) { rc_update_bit_0(rc, prob); distance = cst->rep2; } else { rc_update_bit_1(rc, prob); distance = cst->rep3; cst->rep3 = cst->rep2; } cst->rep2 = cst->rep1; } cst->rep1 = cst->rep0; cst->rep0 = distance; } cst->state = cst->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 (cst->state < 4) { int pos_slot; cst->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) { int i, mi; num_bits = (pos_slot >> 1) - 1; cst->rep0 = 2 | (pos_slot & 1); if (pos_slot < LZMA_END_POS_MODEL_INDEX) { cst->rep0 <<= num_bits; prob = p + LZMA_SPEC_POS + cst->rep0 - pos_slot - 1; } else { num_bits -= LZMA_NUM_ALIGN_BITS; while (num_bits--) cst->rep0 = (cst->rep0 << 1) | rc_direct_bit(rc); prob = p + LZMA_ALIGN; cst->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)) cst->rep0 |= i; i <<= 1; } } else cst->rep0 = pos_slot; if (++(cst->rep0) == 0) return; } len += LZMA_MATCH_MIN_LEN; copy_bytes(wr, cst->rep0, len); } STATIC inline int INIT unlzma(unsigned char *buf, int in_len, int(*fill)(void*, unsigned int), int(*flush)(void*, unsigned int), unsigned char *output, int *posp, void(*error_fn)(char *x) ) { struct lzma_header header; int lc, pb, lp; uint32_t pos_state_mask; uint32_t literal_pos_mask; uint16_t *p; int num_probs; struct rc rc; int i, mi; struct writer wr; struct cstate cst; unsigned char *inbuf; int ret = -1; set_error_fn(error_fn); if (!flush) in_len -= 4; /* Uncompressed size hack active in pre-boot environment */ if (buf) inbuf = buf; else inbuf = malloc(LZMA_IOBUF_SIZE); if (!inbuf) { error("Could not allocate input bufer"); goto exit_0; } cst.state = 0; cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1; wr.header = &header; wr.flush = flush; wr.global_pos = 0; wr.previous_byte = 0; wr.buffer_pos = 0; rc_init(&rc, fill, inbuf, in_len); for (i = 0; i < sizeof(header); i++) { if (rc.ptr >= rc.buffer_end) rc_read(&rc); ((unsigned char *)&header)[i] = *rc.ptr++; } if (header.pos >= (9 * 5 * 5)) error("bad header"); mi = 0; lc = header.pos; while (lc >= 9) { mi++; lc -= 9; } pb = 0; lp = mi; while (lp >= 5) { pb++; lp -= 5; } pos_state_mask = (1 << pb) - 1; literal_pos_mask = (1 << lp) - 1; ENDIAN_CONVERT(header.dict_size); ENDIAN_CONVERT(header.dst_size); if (header.dict_size == 0) header.dict_size = 1; if (output) wr.buffer = output; else { wr.bufsize = MIN(header.dst_size, header.dict_size); wr.buffer = large_malloc(wr.bufsize); } if (wr.buffer == NULL) goto exit_1; num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp)); p = (uint16_t *) large_malloc(num_probs * sizeof(*p)); if (p == 0) goto exit_2; 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_init_code(&rc); while (get_pos(&wr) < header.dst_size) { int pos_state = get_pos(&wr) & pos_state_mask; uint16_t *prob = p + LZMA_IS_MATCH + (cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state; if (rc_is_bit_0(&rc, prob)) process_bit0(&wr, &rc, &cst, p, pos_state, prob, lc, literal_pos_mask); else { process_bit1(&wr, &rc, &cst, p, pos_state, prob); if (cst.rep0 == 0) break; } } if (posp) *posp = rc.ptr-rc.buffer; if (wr.flush) wr.flush(wr.buffer, wr.buffer_pos); ret = 0; large_free(p); exit_2: if (!output) large_free(wr.buffer); exit_1: if (!buf) free(inbuf); exit_0: return ret; } #define decompress unlzma