/* inflate.c -- zlib decompression
 * Copyright (C) 1995-2016 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 * Change history:
 *
 * 1.2.beta0    24 Nov 2002

#ifdef MAKEFIXED
#  ifndef BUILDFIXED
#    define BUILDFIXED
#  endif
#endif

/* function prototypes */
local int inflateStateCheck OF((z_streamp strm));
local void fixedtables OF((struct inflate_state FAR *state));
local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
                           unsigned copy));
#ifdef BUILDFIXED
   void makefixed OF((void));
#endif
local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
                              unsigned len));

local int inflateStateCheck(strm)
z_streamp strm;
{
    struct inflate_state FAR *state;
    if (strm == Z_NULL ||
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
        return 1;
    state = (struct inflate_state FAR *)strm->state;
    if (state == Z_NULL || state->strm != strm ||
        state->mode < HEAD || state->mode > SYNC)
        return 1;
    return 0;
}

int ZEXPORT inflateResetKeep(strm)
z_streamp strm;
{
    struct inflate_state FAR *state;

    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    strm->total_in = strm->total_out = state->total = 0;
    strm->msg = Z_NULL;
    if (state->wrap)        /* to support ill-conceived Java test suite */
        strm->adler = state->wrap & 1;
    state->mode = HEAD;
    state->last = 0;

}

int ZEXPORT inflateReset(strm)
z_streamp strm;
{
    struct inflate_state FAR *state;

    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    state->wsize = 0;
    state->whave = 0;
    state->wnext = 0;
    return inflateResetKeep(strm);
}

int ZEXPORT inflateReset2(strm, windowBits)
z_streamp strm;
int windowBits;
{
    int wrap;
    struct inflate_state FAR *state;

    /* get the state */
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;

    /* extract wrap request from windowBits parameter */
    if (windowBits < 0) {
        wrap = 0;
        windowBits = -windowBits;
    }
    else {
        wrap = (windowBits >> 4) + 5;
#ifdef GUNZIP
        if (windowBits < 48)
            windowBits &= 15;
#endif
    }

    /* set number of window bits, free window if different */

        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->strm = strm;
    state->window = Z_NULL;
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
    ret = inflateReset2(strm, windowBits);
    if (ret != Z_OK) {
        ZFREE(strm, state);
        strm->state = Z_NULL;
    }
    return ret;
}

int ZEXPORT inflatePrime(strm, bits, value)
z_streamp strm;
int bits;
int value;
{
    struct inflate_state FAR *state;

    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (bits < 0) {
        state->hold = 0;
        state->bits = 0;
        return Z_OK;
    }
    if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
    value &= (1L << bits) - 1;
    state->hold += (unsigned)value << state->bits;
    state->bits += (uInt)bits;
    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

    int ret;                    /* return code */
#ifdef GUNZIP
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
#endif
    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};

    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
        (strm->next_in == Z_NULL && strm->avail_in != 0))
        return Z_STREAM_ERROR;

    state = (struct inflate_state FAR *)strm->state;
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
    LOAD();
    in = have;
    out = left;
    ret = Z_OK;
    for (;;)
        switch (state->mode) {
        case HEAD:
            if (state->wrap == 0) {
                state->mode = TYPEDO;
                break;
            }
            NEEDBITS(16);
#ifdef GUNZIP
            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
                if (state->wbits == 0)
                    state->wbits = 15;
                state->check = crc32(0L, Z_NULL, 0);
                CRC2(state->check, hold);
                INITBITS();
                state->mode = FLAGS;
                break;
            }
            state->flags = 0;           /* expect zlib header */

                state->mode = BAD;
                break;
            }
            DROPBITS(4);
            len = BITS(4) + 8;
            if (state->wbits == 0)
                state->wbits = len;
            if (len > 15 || len > state->wbits) {
                strm->msg = (char *)"invalid window size";
                state->mode = BAD;
                break;
            }
            state->dmax = 1U << len;
            Tracev((stderr, "inflate:   zlib header ok\n"));
            strm->adler = state->check = adler32(0L, Z_NULL, 0);

            if (state->flags & 0xe000) {
                strm->msg = (char *)"unknown header flags set";
                state->mode = BAD;
                break;
            }
            if (state->head != Z_NULL)
                state->head->text = (int)((hold >> 8) & 1);
            if ((state->flags & 0x0200) && (state->wrap & 4))
                CRC2(state->check, hold);
            INITBITS();
            state->mode = TIME;
        case TIME:
            NEEDBITS(32);
            if (state->head != Z_NULL)
                state->head->time = hold;
            if ((state->flags & 0x0200) && (state->wrap & 4))
                CRC4(state->check, hold);
            INITBITS();
            state->mode = OS;
        case OS:
            NEEDBITS(16);
            if (state->head != Z_NULL) {
                state->head->xflags = (int)(hold & 0xff);
                state->head->os = (int)(hold >> 8);
            }
            if ((state->flags & 0x0200) && (state->wrap & 4))
                CRC2(state->check, hold);
            INITBITS();
            state->mode = EXLEN;
        case EXLEN:
            if (state->flags & 0x0400) {
                NEEDBITS(16);
                state->length = (unsigned)(hold);
                if (state->head != Z_NULL)
                    state->head->extra_len = (unsigned)hold;
                if ((state->flags & 0x0200) && (state->wrap & 4))
                    CRC2(state->check, hold);
                INITBITS();
            }
            else if (state->head != Z_NULL)
                state->head->extra = Z_NULL;
            state->mode = EXTRA;
        case EXTRA:
            if (state->flags & 0x0400) {
                copy = state->length;
                if (copy > have) copy = have;
                if (copy) {
                    if (state->head != Z_NULL &&
                        state->head->extra != Z_NULL) {
                        len = state->head->extra_len - state->length;
                        zmemcpy(state->head->extra + len, next,
                                len + copy > state->head->extra_max ?
                                state->head->extra_max - len : copy);
                    }
                    if ((state->flags & 0x0200) && (state->wrap & 4))
                        state->check = crc32(state->check, next, copy);
                    have -= copy;
                    next += copy;
                    state->length -= copy;
                }
                if (state->length) goto inf_leave;
            }
            state->length = 0;
            state->mode = NAME;
        case NAME:
            if (state->flags & 0x0800) {
                if (have == 0) goto inf_leave;
                copy = 0;
                do {
                    len = (unsigned)(next[copy++]);
                    if (state->head != Z_NULL &&
                            state->head->name != Z_NULL &&
                            state->length < state->head->name_max)
                        state->head->name[state->length++] = (Bytef)len;
                } while (len && copy < have);
                if ((state->flags & 0x0200) && (state->wrap & 4))
                    state->check = crc32(state->check, next, copy);
                have -= copy;
                next += copy;
                if (len) goto inf_leave;
            }
            else if (state->head != Z_NULL)
                state->head->name = Z_NULL;
            state->length = 0;
            state->mode = COMMENT;
        case COMMENT:
            if (state->flags & 0x1000) {
                if (have == 0) goto inf_leave;
                copy = 0;
                do {
                    len = (unsigned)(next[copy++]);
                    if (state->head != Z_NULL &&
                            state->head->comment != Z_NULL &&
                            state->length < state->head->comm_max)
                        state->head->comment[state->length++] = (Bytef)len;
                } while (len && copy < have);
                if ((state->flags & 0x0200) && (state->wrap & 4))
                    state->check = crc32(state->check, next, copy);
                have -= copy;
                next += copy;
                if (len) goto inf_leave;
            }
            else if (state->head != Z_NULL)
                state->head->comment = Z_NULL;
            state->mode = HCRC;
        case HCRC:
            if (state->flags & 0x0200) {
                NEEDBITS(16);
                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
                    strm->msg = (char *)"header crc mismatch";
                    state->mode = BAD;
                    break;
                }
                INITBITS();
            }
            if (state->head != Z_NULL) {

            break;
        case CHECK:
            if (state->wrap) {
                NEEDBITS(32);
                out -= left;
                strm->total_out += out;
                state->total += out;
                if ((state->wrap & 4) && out)
                    strm->adler = state->check =
                        UPDATE(state->check, put - out, out);
                out = left;
                if ((state->wrap & 4) && (
#ifdef GUNZIP
                     state->flags ? hold :
#endif
                     ZSWAP32(hold)) != state->check) {
                    strm->msg = (char *)"incorrect data check";
                    state->mode = BAD;
                    break;

            return Z_MEM_ERROR;
        }
    in -= strm->avail_in;
    out -= strm->avail_out;
    strm->total_in += in;
    strm->total_out += out;
    state->total += out;
    if ((state->wrap & 4) && out)
        strm->adler = state->check =
            UPDATE(state->check, strm->next_out - out, out);
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
                      (state->mode == TYPE ? 128 : 0) +
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
        ret = Z_BUF_ERROR;
    return ret;
}

int ZEXPORT inflateEnd(strm)
z_streamp strm;
{
    struct inflate_state FAR *state;
    if (inflateStateCheck(strm))
        return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (state->window != Z_NULL) ZFREE(strm, state->window);
    ZFREE(strm, strm->state);
    strm->state = Z_NULL;
    Tracev((stderr, "inflate: end\n"));
    return Z_OK;
}

int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
z_streamp strm;
Bytef *dictionary;
uInt *dictLength;
{
    struct inflate_state FAR *state;

    /* check state */
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;

    /* copy dictionary */
    if (state->whave && dictionary != Z_NULL) {
        zmemcpy(dictionary, state->window + state->wnext,
                state->whave - state->wnext);
        zmemcpy(dictionary + state->whave - state->wnext,

uInt dictLength;
{
    struct inflate_state FAR *state;
    unsigned long dictid;
    int ret;

    /* check state */
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (state->wrap != 0 && state->mode != DICT)
        return Z_STREAM_ERROR;

    /* check for correct dictionary identifier */
    if (state->mode == DICT) {
        dictid = adler32(0L, Z_NULL, 0);

int ZEXPORT inflateGetHeader(strm, head)
z_streamp strm;
gz_headerp head;
{
    struct inflate_state FAR *state;

    /* check state */
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;

    /* save header structure */
    state->head = head;
    head->done = 0;
    return Z_OK;

{
    unsigned len;               /* number of bytes to look at or looked at */
    unsigned long in, out;      /* temporary to save total_in and total_out */
    unsigned char buf[4];       /* to restore bit buffer to byte string */
    struct inflate_state FAR *state;

    /* check parameters */
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;

    /* if first time, start search in bit buffer */
    if (state->mode != SYNC) {
        state->mode = SYNC;
        state->hold <<= state->bits & 7;

   inflate is waiting for these length bytes.
 */
int ZEXPORT inflateSyncPoint(strm)
z_streamp strm;
{
    struct inflate_state FAR *state;

    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    return state->mode == STORED && state->bits == 0;
}

int ZEXPORT inflateCopy(dest, source)
z_streamp dest;
z_streamp source;
{
    struct inflate_state FAR *state;
    struct inflate_state FAR *copy;
    unsigned char FAR *window;
    unsigned wsize;

    /* check input */
    if (inflateStateCheck(source) || dest == Z_NULL)

        return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)source->state;

    /* allocate space */
    copy = (struct inflate_state FAR *)
           ZALLOC(source, 1, sizeof(struct inflate_state));
    if (copy == Z_NULL) return Z_MEM_ERROR;
    window = Z_NULL;
    if (state->window != Z_NULL) {
        window = (unsigned char FAR *)
                 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
        if (window == Z_NULL) {
            ZFREE(source, copy);
            return Z_MEM_ERROR;
        }
    }

    /* copy state */
    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
    zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
    copy->strm = dest;
    if (state->lencode >= state->codes &&
        state->lencode <= state->codes + ENOUGH - 1) {
        copy->lencode = copy->codes + (state->lencode - state->codes);
        copy->distcode = copy->codes + (state->distcode - state->codes);
    }
    copy->next = copy->codes + (state->next - state->codes);
    if (window != Z_NULL) {

int ZEXPORT inflateUndermine(strm, subvert)
z_streamp strm;
int subvert;
{
    struct inflate_state FAR *state;

    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;

#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
    state->sane = !subvert;
    return Z_OK;
#else
    (void)subvert;
    state->sane = 1;
    return Z_DATA_ERROR;
#endif
}

int ZEXPORT inflateValidate(strm, check)
z_streamp strm;
int check;
{
    struct inflate_state FAR *state;

    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
    state = (struct inflate_state FAR *)strm->state;
    if (check)
        state->wrap |= 4;
    else
        state->wrap &= ~4;
    return Z_OK;
}

long ZEXPORT inflateMark(strm)
z_streamp strm;
{
    struct inflate_state FAR *state;

    if (inflateStateCheck(strm))
        return -(1L << 16);
    state = (struct inflate_state FAR *)strm->state;
    return (long)(((unsigned long)((long)state->back)) << 16) +
        (state->mode == COPY ? state->length :
            (state->mode == MATCH ? state->was - state->length : 0));
}

unsigned long ZEXPORT inflateCodesUsed(strm)
z_streamp strm;
{
    struct inflate_state FAR *state;
    if (inflateStateCheck(strm)) return (unsigned long)-1;
    state = (struct inflate_state FAR *)strm->state;
    return (unsigned long)(state->next - state->codes);
}