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Diffstat (limited to 'src/gzip/inflate.c')
| -rw-r--r-- | src/gzip/inflate.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/src/gzip/inflate.c b/src/gzip/inflate.c new file mode 100644 index 0000000..8877fa3 --- /dev/null +++ b/src/gzip/inflate.c @@ -0,0 +1,273 @@ +/* inflate.c -- zlib interface to inflate modules + * Copyright (C) 1995-2002 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "zutil.h" +#include "infblock.h" + +#define DONE INFLATE_DONE +#define BAD INFLATE_BAD + +typedef enum { + METHOD, /* waiting for method byte */ + FLAG, /* waiting for flag byte */ + DICT4, /* four dictionary check bytes to go */ + DICT3, /* three dictionary check bytes to go */ + DICT2, /* two dictionary check bytes to go */ + DICT1, /* one dictionary check byte to go */ + DICT0, /* waiting for inflateSetDictionary */ + BLOCKS, /* decompressing blocks */ + CHECK4, /* four check bytes to go */ + CHECK3, /* three check bytes to go */ + CHECK2, /* two check bytes to go */ + CHECK1, /* one check byte to go */ + DONE, /* finished check, done */ + BAD} /* got an error--stay here */ +inflate_mode; + +/* inflate private state */ +struct internal_state { + + /* mode */ + inflate_mode mode; /* current inflate mode */ + + /* mode dependent information */ + union { + uInt method; /* if FLAGS, method byte */ + struct { + uLong was; /* computed check value */ + uLong need; /* stream check value */ + } check; /* if CHECK, check values to compare */ + uInt marker; /* if BAD, inflateSync's marker bytes count */ + } sub; /* submode */ + + /* mode independent information */ + int nowrap; /* flag for no wrapper */ + uInt wbits; /* log2(window size) (8..15, defaults to 15) */ + inflate_blocks_statef + *blocks; /* current inflate_blocks state */ + +}; + + +ZEXPORT(int) inflateReset( /* z) */ +z_streamp z ) +{ + if (z == Z_NULL || z->state == Z_NULL) + return Z_STREAM_ERROR; + z->total_in = z->total_out = 0; + z->msg = Z_NULL; + z->state->mode = z->state->nowrap ? BLOCKS : METHOD; + inflate_blocks_reset(z->state->blocks, z, Z_NULL); + Tracev((stderr, "inflate: reset\n")); + return Z_OK; +} + + +ZEXPORT(int) inflateEnd( /* z) */ +z_streamp z ) +{ + if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) + return Z_STREAM_ERROR; + if (z->state->blocks != Z_NULL) + inflate_blocks_free(z->state->blocks, z); + ZFREE(z, z->state); + z->state = Z_NULL; + Tracev((stderr, "inflate: end\n")); + return Z_OK; +} + + +ZEXPORT(int) inflateInit2_( /* z, w, version, stream_size) */ +z_streamp z, +int w, +const char *version, +int stream_size ) +{ + if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || + stream_size != sizeof(z_stream)) + return Z_VERSION_ERROR; + + /* initialize state */ + if (z == Z_NULL) + return Z_STREAM_ERROR; + z->msg = Z_NULL; + if (z->zalloc == Z_NULL) + { + z->zalloc = zcalloc; + z->opaque = (voidpf)0; + } + if (z->zfree == Z_NULL) z->zfree = zcfree; + if ((z->state = (struct internal_state FAR *) + ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) + return Z_MEM_ERROR; + z->state->blocks = Z_NULL; + + /* handle undocumented nowrap option (no zlib header or check) */ + z->state->nowrap = 0; + if (w < 0) + { + w = - w; + z->state->nowrap = 1; + } + + /* set window size */ + if (w < 8 || w > 15) + { + inflateEnd(z); + return Z_STREAM_ERROR; + } + z->state->wbits = (uInt)w; + + /* create inflate_blocks state */ + if ((z->state->blocks = + inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) + == Z_NULL) + { + inflateEnd(z); + return Z_MEM_ERROR; + } + Tracev((stderr, "inflate: allocated\n")); + + /* reset state */ + inflateReset(z); + return Z_OK; +} + + + +#undef NEEDBYTE +#define NEEDBYTE {if(z->avail_in==0)return r;r=f;} + +#undef NEXTBYTE +#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) + + +ZEXPORT(int) inflate( /* z, f) */ +z_streamp z, +int f ) +{ + int r; + uInt b; + + if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL) + return Z_STREAM_ERROR; + f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK; + r = Z_BUF_ERROR; + while (1) switch (z->state->mode) + { + case METHOD: + NEEDBYTE + if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) + { + z->state->mode = BAD; + z->msg = (char*)"unknown compression method"; + z->state->sub.marker = 5; /* can't try inflateSync */ + break; + } + if ((z->state->sub.method >> 4) + 8 > z->state->wbits) + { + z->state->mode = BAD; + z->msg = (char*)"invalid window size"; + z->state->sub.marker = 5; /* can't try inflateSync */ + break; + } + z->state->mode = FLAG; + case FLAG: + NEEDBYTE + b = NEXTBYTE; + if (((z->state->sub.method << 8) + b) % 31) + { + z->state->mode = BAD; + z->msg = (char*)"incorrect header check"; + z->state->sub.marker = 5; /* can't try inflateSync */ + break; + } + Tracev((stderr, "inflate: zlib header ok\n")); + if (!(b & PRESET_DICT)) + { + z->state->mode = BLOCKS; + break; + } + z->state->mode = DICT4; + case DICT4: + NEEDBYTE + z->state->sub.check.need = (uLong)NEXTBYTE << 24; + z->state->mode = DICT3; + case DICT3: + NEEDBYTE + z->state->sub.check.need += (uLong)NEXTBYTE << 16; + z->state->mode = DICT2; + case DICT2: + NEEDBYTE + z->state->sub.check.need += (uLong)NEXTBYTE << 8; + z->state->mode = DICT1; + case DICT1: + NEEDBYTE + z->state->sub.check.need += (uLong)NEXTBYTE; + z->adler = z->state->sub.check.need; + z->state->mode = DICT0; + return Z_NEED_DICT; + case DICT0: + z->state->mode = BAD; + z->msg = (char*)"need dictionary"; + z->state->sub.marker = 0; /* can try inflateSync */ + return Z_STREAM_ERROR; + case BLOCKS: + r = inflate_blocks(z->state->blocks, z, r); + if (r == Z_DATA_ERROR) + { + z->state->mode = BAD; + z->state->sub.marker = 0; /* can try inflateSync */ + break; + } + if (r == Z_OK) + r = f; + if (r != Z_STREAM_END) + return r; + r = f; + inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); + if (z->state->nowrap) + { + z->state->mode = DONE; + break; + } + z->state->mode = CHECK4; + case CHECK4: + NEEDBYTE + z->state->sub.check.need = (uLong)NEXTBYTE << 24; + z->state->mode = CHECK3; + case CHECK3: + NEEDBYTE + z->state->sub.check.need += (uLong)NEXTBYTE << 16; + z->state->mode = CHECK2; + case CHECK2: + NEEDBYTE + z->state->sub.check.need += (uLong)NEXTBYTE << 8; + z->state->mode = CHECK1; + case CHECK1: + NEEDBYTE + z->state->sub.check.need += (uLong)NEXTBYTE; + + if (z->state->sub.check.was != z->state->sub.check.need) + { + z->state->mode = BAD; + z->msg = (char*)"incorrect data check"; + z->state->sub.marker = 5; /* can't try inflateSync */ + break; + } + Tracev((stderr, "inflate: zlib check ok\n")); + z->state->mode = DONE; + case DONE: + return Z_STREAM_END; + case BAD: + return Z_DATA_ERROR; + default: + return Z_STREAM_ERROR; + } +#ifdef NEED_DUMMY_RETURN + return Z_STREAM_ERROR; /* Some dumb compilers complain without this */ +#endif +} + |