| /* infback.c -- inflate using a call-back interface |
| * Copyright (C) 1995-2022 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 "zbuild.h" |
| #include "zutil.h" |
| #include "inftrees.h" |
| #include "inflate.h" |
| #include "inflate_p.h" |
| #include "functable.h" |
| |
| /* Avoid conflicts with zlib.h macros */ |
| #ifdef ZLIB_COMPAT |
| # undef inflateBackInit |
| #endif |
| |
| /* |
| strm provides memory allocation functions in zalloc and zfree, or |
| 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. |
| |
| This function is hidden in ZLIB_COMPAT builds. |
| */ |
| int32_t ZNG_CONDEXPORT PREFIX(inflateBackInit)(PREFIX3(stream) *strm, int32_t windowBits, uint8_t *window) { |
| struct inflate_state *state; |
| |
| if (strm == NULL || window == NULL || windowBits < MIN_WBITS || windowBits > MAX_WBITS) |
| return Z_STREAM_ERROR; |
| strm->msg = NULL; /* in case we return an error */ |
| if (strm->zalloc == NULL) { |
| strm->zalloc = PREFIX(zcalloc); |
| strm->opaque = NULL; |
| } |
| if (strm->zfree == NULL) |
| strm->zfree = PREFIX(zcfree); |
| state = ZALLOC_INFLATE_STATE(strm); |
| if (state == NULL) |
| return Z_MEM_ERROR; |
| Tracev((stderr, "inflate: allocated\n")); |
| strm->state = (struct internal_state *)state; |
| state->dmax = 32768U; |
| state->wbits = (unsigned int)windowBits; |
| state->wsize = 1U << windowBits; |
| state->window = window; |
| state->wnext = 0; |
| state->whave = 0; |
| state->sane = 1; |
| state->chunksize = functable.chunksize(); |
| return Z_OK; |
| } |
| |
| /* Function used by zlib.h and zlib-ng version 2.0 macros */ |
| int32_t Z_EXPORT PREFIX(inflateBackInit_)(PREFIX3(stream) *strm, int32_t windowBits, uint8_t *window, |
| const char *version, int32_t stream_size) { |
| if (CHECK_VER_STSIZE(version, stream_size)) |
| return Z_VERSION_ERROR; |
| return PREFIX(inflateBackInit)(strm, windowBits, window); |
| } |
| |
| /* |
| Private macros for inflateBack() |
| Look in inflate_p.h for macros shared with inflate() |
| */ |
| |
| /* 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 = 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)(*next++) << bits); \ |
| bits += 8; \ |
| } 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 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 NULL or the state was not initialized. |
| */ |
| int32_t Z_EXPORT PREFIX(inflateBack)(PREFIX3(stream) *strm, in_func in, void *in_desc, out_func out, void *out_desc) { |
| struct inflate_state *state; |
| z_const unsigned char *next; /* next input */ |
| unsigned char *put; /* next output */ |
| unsigned have, left; /* available input and output */ |
| uint32_t hold; /* bit buffer */ |
| unsigned bits; /* bits in bit buffer */ |
| unsigned copy; /* number of stored or match bytes to copy */ |
| unsigned char *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 */ |
| int32_t ret; /* return code */ |
| static const uint16_t 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 == NULL || strm->state == NULL) |
| return Z_STREAM_ERROR; |
| state = (struct inflate_state *)strm->state; |
| |
| /* Reset the state */ |
| strm->msg = NULL; |
| state->mode = TYPE; |
| state->last = 0; |
| state->whave = 0; |
| next = strm->next_in; |
| have = next != 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 */ |
| PREFIX(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: |
| SET_BAD("invalid block type"); |
| } |
| DROPBITS(2); |
| break; |
| |
| case STORED: |
| /* get and verify stored block length */ |
| BYTEBITS(); /* go to byte boundary */ |
| NEEDBITS(32); |
| if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { |
| SET_BAD("invalid stored block lengths"); |
| break; |
| } |
| state->length = (uint16_t)hold; |
| 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(); |
| copy = MIN(copy, have); |
| copy = MIN(copy, left); |
| memcpy(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) { |
| SET_BAD("too many length or distance symbols"); |
| break; |
| } |
| #endif |
| Tracev((stderr, "inflate: table sizes ok\n")); |
| state->have = 0; |
| |
| /* get code length code lengths (not a typo) */ |
| while (state->have < state->ncode) { |
| NEEDBITS(3); |
| state->lens[order[state->have++]] = (uint16_t)BITS(3); |
| DROPBITS(3); |
| } |
| while (state->have < 19) |
| state->lens[order[state->have++]] = 0; |
| state->next = state->codes; |
| state->lencode = (const code *)(state->next); |
| state->lenbits = 7; |
| ret = zng_inflate_table(CODES, state->lens, 19, &(state->next), &(state->lenbits), state->work); |
| if (ret) { |
| SET_BAD("invalid code lengths set"); |
| break; |
| } |
| Tracev((stderr, "inflate: code lengths ok\n")); |
| state->have = 0; |
| |
| /* get length and distance code code lengths */ |
| while (state->have < state->nlen + state->ndist) { |
| for (;;) { |
| here = state->lencode[BITS(state->lenbits)]; |
| if (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) { |
| SET_BAD("invalid bit length repeat"); |
| break; |
| } |
| len = 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) { |
| SET_BAD("invalid bit length repeat"); |
| break; |
| } |
| while (copy) { |
| --copy; |
| state->lens[state->have++] = (uint16_t)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) { |
| SET_BAD("invalid code -- missing end-of-block"); |
| break; |
| } |
| |
| /* build code tables -- note: do not change the lenbits or distbits |
| values here (10 and 9) without reading the comments in inftrees.h |
| concerning the ENOUGH constants, which depend on those values */ |
| state->next = state->codes; |
| state->lencode = (const code *)(state->next); |
| state->lenbits = 10; |
| ret = zng_inflate_table(LENS, state->lens, state->nlen, &(state->next), &(state->lenbits), state->work); |
| if (ret) { |
| SET_BAD("invalid literal/lengths set"); |
| break; |
| } |
| state->distcode = (const code *)(state->next); |
| state->distbits = 9; |
| ret = zng_inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
| &(state->next), &(state->distbits), state->work); |
| if (ret) { |
| SET_BAD("invalid distances set"); |
| break; |
| } |
| Tracev((stderr, "inflate: codes ok\n")); |
| state->mode = LEN; |
| Z_FALLTHROUGH; |
| |
| case LEN: |
| /* use inflate_fast() if we have enough input and output */ |
| if (have >= INFLATE_FAST_MIN_HAVE && |
| left >= INFLATE_FAST_MIN_LEFT) { |
| RESTORE(); |
| if (state->whave < state->wsize) |
| state->whave = state->wsize - left; |
| functable.inflate_fast(strm, state->wsize); |
| LOAD(); |
| break; |
| } |
| |
| /* get a literal, length, or end-of-block code */ |
| for (;;) { |
| here = state->lencode[BITS(state->lenbits)]; |
| if (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 + (unsigned)here.bits <= bits) |
| break; |
| PULLBYTE(); |
| } |
| DROPBITS(last.bits); |
| } |
| DROPBITS(here.bits); |
| state->length = here.val; |
| |
| /* process literal */ |
| if ((int)(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) { |
| SET_BAD("invalid literal/length code"); |
| break; |
| } |
| |
| /* length code -- get extra bits, if any */ |
| state->extra = (here.op & MAX_BITS); |
| if (state->extra) { |
| 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 (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 + (unsigned)here.bits <= bits) |
| break; |
| PULLBYTE(); |
| } |
| DROPBITS(last.bits); |
| } |
| DROPBITS(here.bits); |
| if (here.op & 64) { |
| SET_BAD("invalid distance code"); |
| break; |
| } |
| state->offset = here.val; |
| state->extra = (here.op & MAX_BITS); |
| |
| /* get distance extra bits, if any */ |
| if (state->extra) { |
| NEEDBITS(state->extra); |
| state->offset += BITS(state->extra); |
| DROPBITS(state->extra); |
| } |
| #ifdef INFLATE_STRICT |
| if (state->offset > state->wsize - (state->whave < state->wsize ? left : 0)) { |
| SET_BAD("invalid distance too far back"); |
| break; |
| } |
| #endif |
| 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; |
| } |
| copy = MIN(copy, state->length); |
| state->length -= copy; |
| left -= copy; |
| do { |
| *put++ = *from++; |
| } while (--copy); |
| } while (state->length != 0); |
| break; |
| |
| case DONE: |
| /* inflate stream terminated properly */ |
| ret = Z_STREAM_END; |
| 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; |
| } |
| |
| /* Write leftover output and return unused input */ |
| inf_leave: |
| if (left < state->wsize) { |
| if (out(out_desc, state->window, state->wsize - left) && (ret == Z_STREAM_END)) { |
| ret = Z_BUF_ERROR; |
| } |
| } |
| strm->next_in = next; |
| strm->avail_in = have; |
| return ret; |
| } |
| |
| int32_t Z_EXPORT PREFIX(inflateBackEnd)(PREFIX3(stream) *strm) { |
| if (strm == NULL || strm->state == NULL || strm->zfree == NULL) |
| return Z_STREAM_ERROR; |
| ZFREE_STATE(strm, strm->state); |
| strm->state = NULL; |
| Tracev((stderr, "inflate: end\n")); |
| return Z_OK; |
| } |
