archival/libarchive/decompress_unlzma.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Small lzma deflate implementation.
   4  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
   5  *
   6  * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
   7  * Copyright (C) 1999-2005  Igor Pavlov
   8  *
   9  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  10  */
  11 #include "libbb.h"
  12 #include "bb_archive.h"
  13
  14 #if ENABLE_FEATURE_LZMA_FAST
  15 #  define speed_inline ALWAYS_INLINE
  16 #  define size_inline
  17 #else
  18 #  define speed_inline
  19 #  define size_inline ALWAYS_INLINE
  20 #endif
  21
  22
  23 typedef struct {
  24         int fd;
  25         uint8_t *ptr;
  26
  27 /* Was keeping rc on stack in unlzma and separately allocating buffer,
  28  * but with "buffer 'attached to' allocated rc" code is smaller: */
  29         /* uint8_t *buffer; */
  30 #define RC_BUFFER ((uint8_t*)(rc+1))
  31
  32         uint8_t *buffer_end;
  33
  34 /* Had provisions for variable buffer, but we don't need it here */
  35         /* int buffer_size; */
  36 #define RC_BUFFER_SIZE 0x10000
  37
  38         uint32_t code;
  39         uint32_t range;
  40         uint32_t bound;
  41 } rc_t;
  42
  43 #define RC_TOP_BITS 24
  44 #define RC_MOVE_BITS 5
  45 #define RC_MODEL_TOTAL_BITS 11
  46
  47
  48 /* Called once in rc_do_normalize() */
  49 static void rc_read(rc_t *rc)
  50 {
  51         int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
  52 //TODO: return -1 instead
  53 //This will make unlzma delete broken unpacked file on unpack errors
  54         if (buffer_size <= 0)
  55                 bb_error_msg_and_die("unexpected EOF");
  56         rc->buffer_end = RC_BUFFER + buffer_size;
  57         rc->ptr = RC_BUFFER;
  58 }
  59
  60 /* Called twice, but one callsite is in speed_inline'd rc_is_bit_1() */
  61 static void rc_do_normalize(rc_t *rc)
  62 {
  63         if (rc->ptr >= rc->buffer_end)
  64                 rc_read(rc);
  65         rc->range <<= 8;
  66         rc->code = (rc->code << 8) | *rc->ptr++;
  67 }
  68
  69 /* Called once */
  70 static ALWAYS_INLINE rc_t* rc_init(int fd) /*, int buffer_size) */
  71 {
  72         int i;
  73         rc_t *rc;
  74
  75         rc = xzalloc(sizeof(*rc) + RC_BUFFER_SIZE);
  76
  77         rc->fd = fd;
  78         /* rc->ptr = rc->buffer_end; */
  79
  80         for (i = 0; i < 5; i++) {
  81                 rc_do_normalize(rc);
  82         }
  83         rc->range = 0xffffffff;
  84         return rc;
  85 }
  86
  87 /* Called once  */
  88 static ALWAYS_INLINE void rc_free(rc_t *rc)
  89 {
  90         free(rc);
  91 }
  92
  93 static ALWAYS_INLINE void rc_normalize(rc_t *rc)
  94 {
  95         if (rc->range < (1 << RC_TOP_BITS)) {
  96                 rc_do_normalize(rc);
  97         }
  98 }
  99
 100 /* rc_is_bit_1 is called 9 times */
 101 static speed_inline int rc_is_bit_1(rc_t *rc, uint16_t *p)
 102 {
 103         rc_normalize(rc);
 104         rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
 105         if (rc->code < rc->bound) {
 106                 rc->range = rc->bound;
 107                 *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
 108                 return 0;
 109         }
 110         rc->range -= rc->bound;
 111         rc->code -= rc->bound;
 112         *p -= *p >> RC_MOVE_BITS;
 113         return 1;
 114 }
 115
 116 /* Called 4 times in unlzma loop */
 117 static speed_inline int rc_get_bit(rc_t *rc, uint16_t *p, int *symbol)
 118 {
 119         int ret = rc_is_bit_1(rc, p);
 120         *symbol = *symbol * 2 + ret;
 121         return ret;
 122 }
 123
 124 /* Called once */
 125 static ALWAYS_INLINE int rc_direct_bit(rc_t *rc)
 126 {
 127         rc_normalize(rc);
 128         rc->range >>= 1;
 129         if (rc->code >= rc->range) {
 130                 rc->code -= rc->range;
 131                 return 1;
 132         }
 133         return 0;
 134 }
 135
 136 /* Called twice */
 137 static speed_inline void
 138 rc_bit_tree_decode(rc_t *rc, uint16_t *p, int num_levels, int *symbol)
 139 {
 140         int i = num_levels;
 141
 142         *symbol = 1;
 143         while (i--)
 144                 rc_get_bit(rc, p + *symbol, symbol);
 145         *symbol -= 1 << num_levels;
 146 }
 147
 148
 149 typedef struct {
 150         uint8_t pos;
 151         uint32_t dict_size;
 152         uint64_t dst_size;
 153 } PACKED lzma_header_t;
 154
 155
 156 /* #defines will force compiler to compute/optimize each one with each usage.
 157  * Have heart and use enum instead. */
 158 enum {
 159         LZMA_BASE_SIZE = 1846,
 160         LZMA_LIT_SIZE  = 768,
 161
 162         LZMA_NUM_POS_BITS_MAX = 4,
 163
 164         LZMA_LEN_NUM_LOW_BITS  = 3,
 165         LZMA_LEN_NUM_MID_BITS  = 3,
 166         LZMA_LEN_NUM_HIGH_BITS = 8,
 167
 168         LZMA_LEN_CHOICE     = 0,
 169         LZMA_LEN_CHOICE_2   = (LZMA_LEN_CHOICE + 1),
 170         LZMA_LEN_LOW        = (LZMA_LEN_CHOICE_2 + 1),
 171         LZMA_LEN_MID        = (LZMA_LEN_LOW \
 172                               + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))),
 173         LZMA_LEN_HIGH       = (LZMA_LEN_MID \
 174                               + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))),
 175         LZMA_NUM_LEN_PROBS  = (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)),
 176
 177         LZMA_NUM_STATES     = 12,
 178         LZMA_NUM_LIT_STATES = 7,
 179
 180         LZMA_START_POS_MODEL_INDEX = 4,
 181         LZMA_END_POS_MODEL_INDEX   = 14,
 182         LZMA_NUM_FULL_DISTANCES    = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),
 183
 184         LZMA_NUM_POS_SLOT_BITS = 6,
 185         LZMA_NUM_LEN_TO_POS_STATES = 4,
 186
 187         LZMA_NUM_ALIGN_BITS = 4,
 188
 189         LZMA_MATCH_MIN_LEN  = 2,
 190
 191         LZMA_IS_MATCH       = 0,
 192         LZMA_IS_REP         = (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
 193         LZMA_IS_REP_G0      = (LZMA_IS_REP + LZMA_NUM_STATES),
 194         LZMA_IS_REP_G1      = (LZMA_IS_REP_G0 + LZMA_NUM_STATES),
 195         LZMA_IS_REP_G2      = (LZMA_IS_REP_G1 + LZMA_NUM_STATES),
 196         LZMA_IS_REP_0_LONG  = (LZMA_IS_REP_G2 + LZMA_NUM_STATES),
 197         LZMA_POS_SLOT       = (LZMA_IS_REP_0_LONG \
 198                               + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
 199         LZMA_SPEC_POS       = (LZMA_POS_SLOT \
 200                               + (LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)),
 201         LZMA_ALIGN          = (LZMA_SPEC_POS \
 202                               + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX),
 203         LZMA_LEN_CODER      = (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)),
 204         LZMA_REP_LEN_CODER  = (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS),
 205         LZMA_LITERAL        = (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS),
 206 };
 207
 208
 209 IF_DESKTOP(long long) int FAST_FUNC
 210 unpack_lzma_stream(transformer_aux_data_t *aux UNUSED_PARAM, int src_fd, int dst_fd)
 211 {
 212         IF_DESKTOP(long long total_written = 0;)
 213         lzma_header_t header;
 214         int lc, pb, lp;
 215         uint32_t pos_state_mask;
 216         uint32_t literal_pos_mask;
 217         uint16_t *p;
 218         int num_bits;
 219         int num_probs;
 220         rc_t *rc;
 221         int i;
 222         uint8_t *buffer;
 223         uint8_t previous_byte = 0;
 224         size_t buffer_pos = 0, global_pos = 0;
 225         int len = 0;
 226         int state = 0;
 227         uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
 228
 229         if (full_read(src_fd, &header, sizeof(header)) != sizeof(header)
 230          || header.pos >= (9 * 5 * 5)
 231         ) {
 232                 bb_error_msg("bad lzma header");
 233                 return -1;
 234         }
 235
 236         i = header.pos / 9;
 237         lc = header.pos % 9;
 238         pb = i / 5;
 239         lp = i % 5;
 240         pos_state_mask = (1 << pb) - 1;
 241         literal_pos_mask = (1 << lp) - 1;
 242
 243         header.dict_size = SWAP_LE32(header.dict_size);
 244         header.dst_size = SWAP_LE64(header.dst_size);
 245
 246         if (header.dict_size == 0)
 247                 header.dict_size++;
 248
 249         buffer = xmalloc(MIN(header.dst_size, header.dict_size));
 250
 251         num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
 252         p = xmalloc(num_probs * sizeof(*p));
 253         num_probs += LZMA_LITERAL - LZMA_BASE_SIZE;
 254         for (i = 0; i < num_probs; i++)
 255                 p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
 256
 257         rc = rc_init(src_fd); /*, RC_BUFFER_SIZE); */
 258
 259         while (global_pos + buffer_pos < header.dst_size) {
 260                 int pos_state = (buffer_pos + global_pos) & pos_state_mask;
 261                 uint16_t *prob = p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
 262
 263                 if (!rc_is_bit_1(rc, prob)) {
 264                         static const char next_state[LZMA_NUM_STATES] =
 265                                 { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 };
 266                         int mi = 1;
 267
 268                         prob = (p + LZMA_LITERAL
 269                                 + (LZMA_LIT_SIZE * ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
 270                                                     + (previous_byte >> (8 - lc))
 271                                                    )
 272                                   )
 273                         );
 274
 275                         if (state >= LZMA_NUM_LIT_STATES) {
 276                                 int match_byte;
 277                                 uint32_t pos = buffer_pos - rep0;
 278
 279                                 while (pos >= header.dict_size)
 280                                         pos += header.dict_size;
 281                                 match_byte = buffer[pos];
 282                                 do {
 283                                         int bit;
 284
 285                                         match_byte <<= 1;
 286                                         bit = match_byte & 0x100;
 287                                         bit ^= (rc_get_bit(rc, prob + 0x100 + bit + mi, &mi) << 8); /* 0x100 or 0 */
 288                                         if (bit)
 289                                                 break;
 290                                 } while (mi < 0x100);
 291                         }
 292                         while (mi < 0x100) {
 293                                 rc_get_bit(rc, prob + mi, &mi);
 294                         }
 295
 296                         state = next_state[state];
 297
 298                         previous_byte = (uint8_t) mi;
 299 #if ENABLE_FEATURE_LZMA_FAST
 300  one_byte1:
 301                         buffer[buffer_pos++] = previous_byte;
 302                         if (buffer_pos == header.dict_size) {
 303                                 buffer_pos = 0;
 304                                 global_pos += header.dict_size;
 305                                 if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
 306                                         goto bad;
 307                                 IF_DESKTOP(total_written += header.dict_size;)
 308                         }
 309 #else
 310                         len = 1;
 311                         goto one_byte2;
 312 #endif
 313                 } else {
 314                         int offset;
 315                         uint16_t *prob2;
 316 #define prob_len prob2
 317
 318                         prob2 = p + LZMA_IS_REP + state;
 319                         if (!rc_is_bit_1(rc, prob2)) {
 320                                 rep3 = rep2;
 321                                 rep2 = rep1;
 322                                 rep1 = rep0;
 323                                 state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
 324                                 prob2 = p + LZMA_LEN_CODER;
 325                         } else {
 326                                 prob2 += LZMA_IS_REP_G0 - LZMA_IS_REP;
 327                                 if (!rc_is_bit_1(rc, prob2)) {
 328                                         prob2 = (p + LZMA_IS_REP_0_LONG
 329                                                 + (state << LZMA_NUM_POS_BITS_MAX)
 330                                                 + pos_state
 331                                         );
 332                                         if (!rc_is_bit_1(rc, prob2)) {
 333 #if ENABLE_FEATURE_LZMA_FAST
 334                                                 uint32_t pos = buffer_pos - rep0;
 335                                                 state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
 336                                                 while (pos >= header.dict_size)
 337                                                         pos += header.dict_size;
 338                                                 previous_byte = buffer[pos];
 339                                                 goto one_byte1;
 340 #else
 341                                                 state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
 342                                                 len = 1;
 343                                                 goto string;
 344 #endif
 345                                         }
 346                                 } else {
 347                                         uint32_t distance;
 348
 349                                         prob2 += LZMA_IS_REP_G1 - LZMA_IS_REP_G0;
 350                                         distance = rep1;
 351                                         if (rc_is_bit_1(rc, prob2)) {
 352                                                 prob2 += LZMA_IS_REP_G2 - LZMA_IS_REP_G1;
 353                                                 distance = rep2;
 354                                                 if (rc_is_bit_1(rc, prob2)) {
 355                                                         distance = rep3;
 356                                                         rep3 = rep2;
 357                                                 }
 358                                                 rep2 = rep1;
 359                                         }
 360                                         rep1 = rep0;
 361                                         rep0 = distance;
 362                                 }
 363                                 state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
 364                                 prob2 = p + LZMA_REP_LEN_CODER;
 365                         }
 366
 367                         prob_len = prob2 + LZMA_LEN_CHOICE;
 368                         num_bits = LZMA_LEN_NUM_LOW_BITS;
 369                         if (!rc_is_bit_1(rc, prob_len)) {
 370                                 prob_len += LZMA_LEN_LOW - LZMA_LEN_CHOICE
 371                                             + (pos_state << LZMA_LEN_NUM_LOW_BITS);
 372                                 offset = 0;
 373                         } else {
 374                                 prob_len += LZMA_LEN_CHOICE_2 - LZMA_LEN_CHOICE;
 375                                 if (!rc_is_bit_1(rc, prob_len)) {
 376                                         prob_len += LZMA_LEN_MID - LZMA_LEN_CHOICE_2
 377                                                     + (pos_state << LZMA_LEN_NUM_MID_BITS);
 378                                         offset = 1 << LZMA_LEN_NUM_LOW_BITS;
 379                                         num_bits += LZMA_LEN_NUM_MID_BITS - LZMA_LEN_NUM_LOW_BITS;
 380                                 } else {
 381                                         prob_len += LZMA_LEN_HIGH - LZMA_LEN_CHOICE_2;
 382                                         offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
 383                                                   + (1 << LZMA_LEN_NUM_MID_BITS));
 384                                         num_bits += LZMA_LEN_NUM_HIGH_BITS - LZMA_LEN_NUM_LOW_BITS;
 385                                 }
 386                         }
 387                         rc_bit_tree_decode(rc, prob_len, num_bits, &len);
 388                         len += offset;
 389
 390                         if (state < 4) {
 391                                 int pos_slot;
 392                                 uint16_t *prob3;
 393
 394                                 state += LZMA_NUM_LIT_STATES;
 395                                 prob3 = p + LZMA_POS_SLOT +
 396                                        ((len < LZMA_NUM_LEN_TO_POS_STATES ? len :
 397                                          LZMA_NUM_LEN_TO_POS_STATES - 1)
 398                                          << LZMA_NUM_POS_SLOT_BITS);
 399                                 rc_bit_tree_decode(rc, prob3,
 400                                         LZMA_NUM_POS_SLOT_BITS, &pos_slot);
 401                                 rep0 = pos_slot;
 402                                 if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
 403                                         int i2, mi2, num_bits2 = (pos_slot >> 1) - 1;
 404                                         rep0 = 2 | (pos_slot & 1);
 405                                         if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
 406                                                 rep0 <<= num_bits2;
 407                                                 prob3 = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
 408                                         } else {
 409                                                 for (; num_bits2 != LZMA_NUM_ALIGN_BITS; num_bits2--)
 410                                                         rep0 = (rep0 << 1) | rc_direct_bit(rc);
 411                                                 rep0 <<= LZMA_NUM_ALIGN_BITS;
 412                                                 prob3 = p + LZMA_ALIGN;
 413                                         }
 414                                         i2 = 1;
 415                                         mi2 = 1;
 416                                         while (num_bits2--) {
 417                                                 if (rc_get_bit(rc, prob3 + mi2, &mi2))
 418                                                         rep0 |= i2;
 419                                                 i2 <<= 1;
 420                                         }
 421                                 }
 422                                 if (++rep0 == 0)
 423                                         break;
 424                         }
 425
 426                         len += LZMA_MATCH_MIN_LEN;
 427  IF_NOT_FEATURE_LZMA_FAST(string:)
 428                         do {
 429                                 uint32_t pos = buffer_pos - rep0;
 430                                 while (pos >= header.dict_size)
 431                                         pos += header.dict_size;
 432                                 previous_byte = buffer[pos];
 433  IF_NOT_FEATURE_LZMA_FAST(one_byte2:)
 434                                 buffer[buffer_pos++] = previous_byte;
 435                                 if (buffer_pos == header.dict_size) {
 436                                         buffer_pos = 0;
 437                                         global_pos += header.dict_size;
 438                                         if (full_write(dst_fd, buffer, header.dict_size) != (ssize_t)header.dict_size)
 439                                                 goto bad;
 440                                         IF_DESKTOP(total_written += header.dict_size;)
 441                                 }
 442                                 len--;
 443                         } while (len != 0 && buffer_pos < header.dst_size);
 444                 }
 445         }
 446
 447         {
 448                 IF_NOT_DESKTOP(int total_written = 0; /* success */)
 449                 IF_DESKTOP(total_written += buffer_pos;)
 450                 if (full_write(dst_fd, buffer, buffer_pos) != (ssize_t)buffer_pos) {
 451  bad:
 452                         total_written = -1; /* failure */
 453                 }
 454                 rc_free(rc);
 455                 free(p);
 456                 free(buffer);
 457                 return total_written;
 458         }
 459 }