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Diffstat (limited to 'zlib/infback.c')
| -rw-r--r-- | zlib/infback.c | 640 |
1 files changed, 640 insertions, 0 deletions
diff --git a/zlib/infback.c b/zlib/infback.c new file mode 100644 index 0000000..59679ec --- /dev/null +++ b/zlib/infback.c @@ -0,0 +1,640 @@ +/* infback.c -- inflate using a call-back interface + * Copyright (C) 1995-2016 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* + This code is largely copied from inflate.c. Normally either infback.o or + inflate.o would be linked into an application--not both. The interface + with inffast.c is retained so that optimized assembler-coded versions of + inflate_fast() can be used with either inflate.c or infback.c. + */ + +#include "zutil.h" +#include "inftrees.h" +#include "inflate.h" +#include "inffast.h" + +/* function prototypes */ +local void fixedtables OF((struct inflate_state FAR *state)); + +/* + strm provides memory allocation functions in zalloc and zfree, or + Z_NULL to use the library memory allocation functions. + + windowBits is in the range 8..15, and window is a user-supplied + window and output buffer that is 2**windowBits bytes. + */ +int ZEXPORT inflateBackInit_(strm, windowBits, window, version, stream_size) +z_streamp strm; +int windowBits; +unsigned char FAR *window; +const char *version; +int stream_size; +{ + struct inflate_state FAR *state; + + if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || + stream_size != (int)(sizeof(z_stream))) + return Z_VERSION_ERROR; + if (strm == Z_NULL || window == Z_NULL || + windowBits < 8 || windowBits > 15) + return Z_STREAM_ERROR; + strm->msg = Z_NULL; /* in case we return an error */ + if (strm->zalloc == (alloc_func)0) { +#ifdef Z_SOLO + return Z_STREAM_ERROR; +#else + strm->zalloc = zcalloc; + strm->opaque = (voidpf)0; +#endif + } + if (strm->zfree == (free_func)0) +#ifdef Z_SOLO + return Z_STREAM_ERROR; +#else + strm->zfree = zcfree; +#endif + state = (struct inflate_state FAR *)ZALLOC(strm, 1, + sizeof(struct inflate_state)); + if (state == Z_NULL) return Z_MEM_ERROR; + Tracev((stderr, "inflate: allocated\n")); + strm->state = (struct internal_state FAR *)state; + state->dmax = 32768U; + state->wbits = (uInt)windowBits; + state->wsize = 1U << windowBits; + state->window = window; + state->wnext = 0; + state->whave = 0; + return Z_OK; +} + +/* + Return state with length and distance decoding tables and index sizes set to + fixed code decoding. Normally this returns fixed tables from inffixed.h. + If BUILDFIXED is defined, then instead this routine builds the tables the + first time it's called, and returns those tables the first time and + thereafter. This reduces the size of the code by about 2K bytes, in + exchange for a little execution time. However, BUILDFIXED should not be + used for threaded applications, since the rewriting of the tables and virgin + may not be thread-safe. + */ +local void fixedtables(state) +struct inflate_state FAR *state; +{ +#ifdef BUILDFIXED + static int virgin = 1; + static code *lenfix, *distfix; + static code fixed[544]; + + /* build fixed huffman tables if first call (may not be thread safe) */ + if (virgin) { + unsigned sym, bits; + static code *next; + + /* literal/length table */ + sym = 0; + while (sym < 144) state->lens[sym++] = 8; + while (sym < 256) state->lens[sym++] = 9; + while (sym < 280) state->lens[sym++] = 7; + while (sym < 288) state->lens[sym++] = 8; + next = fixed; + lenfix = next; + bits = 9; + inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work); + + /* distance table */ + sym = 0; + while (sym < 32) state->lens[sym++] = 5; + distfix = next; + bits = 5; + inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work); + + /* do this just once */ + virgin = 0; + } +#else /* !BUILDFIXED */ +# include "inffixed.h" +#endif /* BUILDFIXED */ + state->lencode = lenfix; + state->lenbits = 9; + state->distcode = distfix; + state->distbits = 5; +} + +/* Macros for inflateBack(): */ + +/* Load returned state from inflate_fast() */ +#define LOAD() \ + do { \ + put = strm->next_out; \ + left = strm->avail_out; \ + next = strm->next_in; \ + have = strm->avail_in; \ + hold = state->hold; \ + bits = state->bits; \ + } while (0) + +/* Set state from registers for inflate_fast() */ +#define RESTORE() \ + do { \ + strm->next_out = put; \ + strm->avail_out = left; \ + strm->next_in = next; \ + strm->avail_in = have; \ + state->hold = hold; \ + state->bits = bits; \ + } while (0) + +/* Clear the input bit accumulator */ +#define INITBITS() \ + do { \ + hold = 0; \ + bits = 0; \ + } while (0) + +/* Assure that some input is available. If input is requested, but denied, + then return a Z_BUF_ERROR from inflateBack(). */ +#define PULL() \ + do { \ + if (have == 0) { \ + have = in(in_desc, &next); \ + if (have == 0) { \ + next = Z_NULL; \ + ret = Z_BUF_ERROR; \ + goto inf_leave; \ + } \ + } \ + } while (0) + +/* Get a byte of input into the bit accumulator, or return from inflateBack() + with an error if there is no input available. */ +#define PULLBYTE() \ + do { \ + PULL(); \ + have--; \ + hold += (unsigned long)(*next++) << bits; \ + bits += 8; \ + } while (0) + +/* Assure that there are at least n bits in the bit accumulator. If there is + not enough available input to do that, then return from inflateBack() with + an error. */ +#define NEEDBITS(n) \ + do { \ + while (bits < (unsigned)(n)) \ + PULLBYTE(); \ + } while (0) + +/* Return the low n bits of the bit accumulator (n < 16) */ +#define BITS(n) \ + ((unsigned)hold & ((1U << (n)) - 1)) + +/* Remove n bits from the bit accumulator */ +#define DROPBITS(n) \ + do { \ + hold >>= (n); \ + bits -= (unsigned)(n); \ + } while (0) + +/* Remove zero to seven bits as needed to go to a byte boundary */ +#define BYTEBITS() \ + do { \ + hold >>= bits & 7; \ + bits -= bits & 7; \ + } while (0) + +/* Assure that some output space is available, by writing out the window + if it's full. If the write fails, return from inflateBack() with a + Z_BUF_ERROR. */ +#define ROOM() \ + do { \ + if (left == 0) { \ + put = state->window; \ + left = state->wsize; \ + state->whave = left; \ + if (out(out_desc, put, left)) { \ + ret = Z_BUF_ERROR; \ + goto inf_leave; \ + } \ + } \ + } while (0) + +/* + strm provides the memory allocation functions and window buffer on input, + and provides information on the unused input on return. For Z_DATA_ERROR + returns, strm will also provide an error message. + + in() and out() are the call-back input and output functions. When + inflateBack() needs more input, it calls in(). When inflateBack() has + filled the window with output, or when it completes with data in the + window, it calls out() to write out the data. The application must not + change the provided input until in() is called again or inflateBack() + returns. The application must not change the window/output buffer until + inflateBack() returns. + + in() and out() are called with a descriptor parameter provided in the + inflateBack() call. This parameter can be a structure that provides the + information required to do the read or write, as well as accumulated + information on the input and output such as totals and check values. + + in() should return zero on failure. out() should return non-zero on + failure. If either in() or out() fails, than inflateBack() returns a + Z_BUF_ERROR. strm->next_in can be checked for Z_NULL to see whether it + was in() or out() that caused in the error. Otherwise, inflateBack() + returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format + error, or Z_MEM_ERROR if it could not allocate memory for the state. + inflateBack() can also return Z_STREAM_ERROR if the input parameters + are not correct, i.e. strm is Z_NULL or the state was not initialized. + */ +int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc) +z_streamp strm; +in_func in; +void FAR *in_desc; +out_func out; +void FAR *out_desc; +{ + struct inflate_state FAR *state; + z_const unsigned char FAR *next; /* next input */ + unsigned char FAR *put; /* next output */ + unsigned have, left; /* available input and output */ + unsigned long hold; /* bit buffer */ + unsigned bits; /* bits in bit buffer */ + unsigned copy; /* number of stored or match bytes to copy */ + unsigned char FAR *from; /* where to copy match bytes from */ + code here; /* current decoding table entry */ + code last; /* parent table entry */ + unsigned len; /* length to copy for repeats, bits to drop */ + int ret; /* return code */ + static const unsigned short order[19] = /* permutation of code lengths */ + {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; + + /* Check that the strm exists and that the state was initialized */ + if (strm == Z_NULL || strm->state == Z_NULL) + return Z_STREAM_ERROR; + state = (struct inflate_state FAR *)strm->state; + + /* Reset the state */ + strm->msg = Z_NULL; + state->mode = TYPE; + state->last = 0; + state->whave = 0; + next = strm->next_in; + have = next != Z_NULL ? strm->avail_in : 0; + hold = 0; + bits = 0; + put = state->window; + left = state->wsize; + + /* Inflate until end of block marked as last */ + for (;;) + switch (state->mode) { + case TYPE: + /* determine and dispatch block type */ + if (state->last) { + BYTEBITS(); + state->mode = DONE; + break; + } + NEEDBITS(3); + state->last = BITS(1); + DROPBITS(1); + switch (BITS(2)) { + case 0: /* stored block */ + Tracev((stderr, "inflate: stored block%s\n", + state->last ? " (last)" : "")); + state->mode = STORED; + break; + case 1: /* fixed block */ + fixedtables(state); + Tracev((stderr, "inflate: fixed codes block%s\n", + state->last ? " (last)" : "")); + state->mode = LEN; /* decode codes */ + break; + case 2: /* dynamic block */ + Tracev((stderr, "inflate: dynamic codes block%s\n", + state->last ? " (last)" : "")); + state->mode = TABLE; + break; + case 3: + strm->msg = (char *)"invalid block type"; + state->mode = BAD; + } + DROPBITS(2); + break; + + case STORED: + /* get and verify stored block length */ + BYTEBITS(); /* go to byte boundary */ + NEEDBITS(32); + if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { + strm->msg = (char *)"invalid stored block lengths"; + state->mode = BAD; + break; + } + state->length = (unsigned)hold & 0xffff; + Tracev((stderr, "inflate: stored length %u\n", + state->length)); + INITBITS(); + + /* copy stored block from input to output */ + while (state->length != 0) { + copy = state->length; + PULL(); + ROOM(); + if (copy > have) copy = have; + if (copy > left) copy = left; + zmemcpy(put, next, copy); + have -= copy; + next += copy; + left -= copy; + put += copy; + state->length -= copy; + } + Tracev((stderr, "inflate: stored end\n")); + state->mode = TYPE; + break; + + case TABLE: + /* get dynamic table entries descriptor */ + NEEDBITS(14); + state->nlen = BITS(5) + 257; + DROPBITS(5); + state->ndist = BITS(5) + 1; + DROPBITS(5); + state->ncode = BITS(4) + 4; + DROPBITS(4); +#ifndef PKZIP_BUG_WORKAROUND + if (state->nlen > 286 || state->ndist > 30) { + strm->msg = (char *)"too many length or distance symbols"; + state->mode = BAD; + break; + } +#endif + Tracev((stderr, "inflate: table sizes ok\n")); + + /* get code length code lengths (not a typo) */ + state->have = 0; + while (state->have < state->ncode) { + NEEDBITS(3); + state->lens[order[state->have++]] = (unsigned short)BITS(3); + DROPBITS(3); + } + while (state->have < 19) + state->lens[order[state->have++]] = 0; + state->next = state->codes; + state->lencode = (code const FAR *)(state->next); + state->lenbits = 7; + ret = inflate_table(CODES, state->lens, 19, &(state->next), + &(state->lenbits), state->work); + if (ret) { + strm->msg = (char *)"invalid code lengths set"; + state->mode = BAD; + break; + } + Tracev((stderr, "inflate: code lengths ok\n")); + + /* get length and distance code code lengths */ + state->have = 0; + while (state->have < state->nlen + state->ndist) { + for (;;) { + here = state->lencode[BITS(state->lenbits)]; + if ((unsigned)(here.bits) <= bits) break; + PULLBYTE(); + } + if (here.val < 16) { + DROPBITS(here.bits); + state->lens[state->have++] = here.val; + } + else { + if (here.val == 16) { + NEEDBITS(here.bits + 2); + DROPBITS(here.bits); + if (state->have == 0) { + strm->msg = (char *)"invalid bit length repeat"; + state->mode = BAD; + break; + } + len = (unsigned)(state->lens[state->have - 1]); + copy = 3 + BITS(2); + DROPBITS(2); + } + else if (here.val == 17) { + NEEDBITS(here.bits + 3); + DROPBITS(here.bits); + len = 0; + copy = 3 + BITS(3); + DROPBITS(3); + } + else { + NEEDBITS(here.bits + 7); + DROPBITS(here.bits); + len = 0; + copy = 11 + BITS(7); + DROPBITS(7); + } + if (state->have + copy > state->nlen + state->ndist) { + strm->msg = (char *)"invalid bit length repeat"; + state->mode = BAD; + break; + } + while (copy--) + state->lens[state->have++] = (unsigned short)len; + } + } + + /* handle error breaks in while */ + if (state->mode == BAD) break; + + /* check for end-of-block code (better have one) */ + if (state->lens[256] == 0) { + strm->msg = (char *)"invalid code -- missing end-of-block"; + state->mode = BAD; + break; + } + + /* build code tables -- note: do not change the lenbits or distbits + values here (9 and 6) without reading the comments in inftrees.h + concerning the ENOUGH constants, which depend on those values */ + state->next = state->codes; + state->lencode = (code const FAR *)(state->next); + state->lenbits = 9; + ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), + &(state->lenbits), state->work); + if (ret) { + strm->msg = (char *)"invalid literal/lengths set"; + state->mode = BAD; + break; + } + state->distcode = (code const FAR *)(state->next); + state->distbits = 6; + ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, + &(state->next), &(state->distbits), state->work); + if (ret) { + strm->msg = (char *)"invalid distances set"; + state->mode = BAD; + break; + } + Tracev((stderr, "inflate: codes ok\n")); + state->mode = LEN; + + case LEN: + /* use inflate_fast() if we have enough input and output */ + if (have >= 6 && left >= 258) { + RESTORE(); + if (state->whave < state->wsize) + state->whave = state->wsize - left; + inflate_fast(strm, state->wsize); + LOAD(); + break; + } + + /* get a literal, length, or end-of-block code */ + for (;;) { + here = state->lencode[BITS(state->lenbits)]; + if ((unsigned)(here.bits) <= bits) break; + PULLBYTE(); + } + if (here.op && (here.op & 0xf0) == 0) { + last = here; + for (;;) { + here = state->lencode[last.val + + (BITS(last.bits + last.op) >> last.bits)]; + if ((unsigned)(last.bits + here.bits) <= bits) break; + PULLBYTE(); + } + DROPBITS(last.bits); + } + DROPBITS(here.bits); + state->length = (unsigned)here.val; + + /* process literal */ + if (here.op == 0) { + Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ? + "inflate: literal '%c'\n" : + "inflate: literal 0x%02x\n", here.val)); + ROOM(); + *put++ = (unsigned char)(state->length); + left--; + state->mode = LEN; + break; + } + + /* process end of block */ + if (here.op & 32) { + Tracevv((stderr, "inflate: end of block\n")); + state->mode = TYPE; + break; + } + + /* invalid code */ + if (here.op & 64) { + strm->msg = (char *)"invalid literal/length code"; + state->mode = BAD; + break; + } + + /* length code -- get extra bits, if any */ + state->extra = (unsigned)(here.op) & 15; + if (state->extra != 0) { + NEEDBITS(state->extra); + state->length += BITS(state->extra); + DROPBITS(state->extra); + } + Tracevv((stderr, "inflate: length %u\n", state->length)); + + /* get distance code */ + for (;;) { + here = state->distcode[BITS(state->distbits)]; + if ((unsigned)(here.bits) <= bits) break; + PULLBYTE(); + } + if ((here.op & 0xf0) == 0) { + last = here; + for (;;) { + here = state->distcode[last.val + + (BITS(last.bits + last.op) >> last.bits)]; + if ((unsigned)(last.bits + here.bits) <= bits) break; + PULLBYTE(); + } + DROPBITS(last.bits); + } + DROPBITS(here.bits); + if (here.op & 64) { + strm->msg = (char *)"invalid distance code"; + state->mode = BAD; + break; + } + state->offset = (unsigned)here.val; + + /* get distance extra bits, if any */ + state->extra = (unsigned)(here.op) & 15; + if (state->extra != 0) { + NEEDBITS(state->extra); + state->offset += BITS(state->extra); + DROPBITS(state->extra); + } + if (state->offset > state->wsize - (state->whave < state->wsize ? + left : 0)) { + strm->msg = (char *)"invalid distance too far back"; + state->mode = BAD; + break; + } + Tracevv((stderr, "inflate: distance %u\n", state->offset)); + + /* copy match from window to output */ + do { + ROOM(); + copy = state->wsize - state->offset; + if (copy < left) { + from = put + copy; + copy = left - copy; + } + else { + from = put - state->offset; + copy = left; + } + if (copy > state->length) copy = state->length; + state->length -= copy; + left -= copy; + do { + *put++ = *from++; + } while (--copy); + } while (state->length != 0); + break; + + case DONE: + /* inflate stream terminated properly -- write leftover output */ + ret = Z_STREAM_END; + if (left < state->wsize) { + if (out(out_desc, state->window, state->wsize - left)) + ret = Z_BUF_ERROR; + } + goto inf_leave; + + case BAD: + ret = Z_DATA_ERROR; + goto inf_leave; + + default: /* can't happen, but makes compilers happy */ + ret = Z_STREAM_ERROR; + goto inf_leave; + } + + /* Return unused input */ + inf_leave: + strm->next_in = next; + strm->avail_in = have; + return ret; +} + +int ZEXPORT inflateBackEnd(strm) +z_streamp strm; +{ + if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0) + return Z_STREAM_ERROR; + ZFREE(strm, strm->state); + strm->state = Z_NULL; + Tracev((stderr, "inflate: end\n")); + return Z_OK; +} |