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#define DEBG(x)

#define DEBG1(x)

/* inflate.c -- Not copyrighted 1992 by Mark Adler

   version c10p1, 10 January 1993 */

/*

 * Adapted for booting Linux by Hannu Savolainen 1993

 * based on gzip-1.0.3

 */

#ifndef lint

static char rcsid[] = "$Id: inflate.c,v 1.1 2005-12-20 09:50:28 jcastillo Exp $";

#endif

#include "gzip.h"

#define slide window

#if defined(STDC_HEADERS) || defined(HAVE_STDLIB_H)

#  include <sys/types.h>

#  include <stdlib.h>

#endif

struct huft {

  uch e;                /* number of extra bits or operation */

  uch b;                /* number of bits in this code or subcode */

  union {

    ush n;              /* literal, length base, or distance base */

    struct huft *t;     /* pointer to next level of table */

  } v;

};

/* Function prototypes */

int huft_build OF((unsigned *, unsigned, unsigned, ush *, ush *,

                   struct huft **, int *));

int huft_free OF((struct huft *));

int inflate_codes OF((struct huft *, struct huft *, int, int));

int inflate_stored OF((void));

int inflate_fixed OF((void));

int inflate_dynamic OF((void));

int inflate_block OF((int *));

int inflate OF((void));

#define wp outcnt

#define flush_output(w) (wp=(w),flush_window())

/* Tables for deflate from PKZIP's appnote.txt. */

static unsigned border[] = {    /* Order of the bit length code lengths */

        16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};

static ush cplens[] = {         /* Copy lengths for literal codes 257..285 */

        3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,

        35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};

        /* note: see note #13 above about the 258 in this list. */

static ush cplext[] = {         /* Extra bits for literal codes 257..285 */

        0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,

        3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */

static ush cpdist[] = {         /* Copy offsets for distance codes 0..29 */

        1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,

        257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,

        8193, 12289, 16385, 24577};

static ush cpdext[] = {         /* Extra bits for distance codes */

        0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,

        7, 7, 8, 8, 9, 9, 10, 10, 11, 11,

        12, 12, 13, 13};

ulg bb;                         /* bit buffer */

unsigned bk;                    /* bits in bit buffer */

ush mask_bits[] = {

    0x0000,

    0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,

    0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff

};

#ifdef CRYPT

  uch cc;

#  define NEXTBYTE() \

     (decrypt ? (cc = get_byte(), zdecode(cc), cc) : get_byte())

#else

#  define NEXTBYTE()  (uch)get_byte()

#endif

#define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}

#define DUMPBITS(n) {b>>=(n);k-=(n);}

int lbits = 9;          /* bits in base literal/length lookup table */

int dbits = 6;          /* bits in base distance lookup table */

/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */

#define BMAX 16         /* maximum bit length of any code (16 for explode) */

#define N_MAX 288       /* maximum number of codes in any set */

unsigned hufts;         /* track memory usage */

int huft_build(b, n, s, d, e, t, m)

unsigned *b;            /* code lengths in bits (all assumed <= BMAX) */

unsigned n;             /* number of codes (assumed <= N_MAX) */

unsigned s;             /* number of simple-valued codes (0..s-1) */

ush *d;                 /* list of base values for non-simple codes */

ush *e;                 /* list of extra bits for non-simple codes */

struct huft **t;        /* result: starting table */

int *m;                 /* maximum lookup bits, returns actual */

/* Given a list of code lengths and a maximum table size, make a set of

   tables to decode that set of codes.  Return zero on success, one if

   the given code set is incomplete (the tables are still built in this

   case), two if the input is invalid (all zero length codes or an

   oversubscribed set of lengths), and three if not enough memory. */

{

  unsigned a;                   /* counter for codes of length k */

  unsigned c[BMAX+1];           /* bit length count table */

  unsigned f;                   /* i repeats in table every f entries */

  int g;                        /* maximum code length */

  int h;                        /* table level */

  register unsigned i;          /* counter, current code */

  register unsigned j;          /* counter */

  register int k;               /* number of bits in current code */

  int l;                        /* bits per table (returned in m) */

  register unsigned *p;         /* pointer into c[], b[], or v[] */

  register struct huft *q;      /* points to current table */

  struct huft r;                /* table entry for structure assignment */

  struct huft *u[BMAX];         /* table stack */

  unsigned v[N_MAX];            /* values in order of bit length */

  register int w;               /* bits before this table == (l * h) */

  unsigned x[BMAX+1];           /* bit offsets, then code stack */

  unsigned *xp;                 /* pointer into x */

  int y;                        /* number of dummy codes added */

  unsigned z;                   /* number of entries in current table */

DEBG("huft1 ");

  /* Generate counts for each bit length */

  memzero(c, sizeof(c));

  p = b;  i = n;

  do {

    c[*p++]++;                  /* assume all entries <= BMAX */

  } while (--i);

  if (c[0] == n)                /* null input--all zero length codes */

  {

    *t = (struct huft *)NULL;

    *m = 0;

    return 0;

  }

DEBG("huft2 ");

  /* Find minimum and maximum length, bound *m by those */

  l = *m;

  for (j = 1; j <= BMAX; j++)

    if (c[j])

      break;

  k = j;                        /* minimum code length */

  if ((unsigned)l < j)

    l = j;

  for (i = BMAX; i; i--)

    if (c[i])

      break;

  g = i;                        /* maximum code length */

  if ((unsigned)l > i)

    l = i;

  *m = l;

DEBG("huft3 ");

  /* Adjust last length count to fill out codes, if needed */

  for (y = 1 << j; j < i; j++, y <<= 1)

    if ((y -= c[j]) < 0)

      return 2;                 /* bad input: more codes than bits */

  if ((y -= c[i]) < 0)

    return 2;

  c[i] += y;

DEBG("huft4 ");

  /* Generate starting offsets into the value table for each length */

  x[1] = j = 0;

  p = c + 1;  xp = x + 2;

  while (--i) {                 /* note that i == g from above */

    *xp++ = (j += *p++);

  }

DEBG("huft5 ");

  /* Make a table of values in order of bit lengths */

  p = b;  i = 0;

  do {

    if ((j = *p++) != 0)

      v[x[j]++] = i;

  } while (++i < n);

DEBG("h6 ");

  /* Generate the Huffman codes and for each, make the table entries */

  x[0] = i = 0;                 /* first Huffman code is zero */

  p = v;                        /* grab values in bit order */

  h = -1;                       /* no tables yet--level -1 */

  w = -l;                       /* bits decoded == (l * h) */

  u[0] = (struct huft *)NULL;   /* just to keep compilers happy */

  q = (struct huft *)NULL;      /* ditto */

  z = 0;                        /* ditto */

DEBG("h6a ");

  /* go through the bit lengths (k already is bits in shortest code) */

  for (; k <= g; k++)

  {

DEBG("h6b ");

    a = c[k];

    while (a--)

    {

DEBG("h6b1 ");

      /* here i is the Huffman code of length k bits for value *p */

      /* make tables up to required level */

      while (k > w + l)

      {

DEBG1("1 ");

        h++;

        w += l;                 /* previous table always l bits */

        /* compute minimum size table less than or equal to l bits */

        z = (z = g - w) > (unsigned)l ? l : z;  /* upper limit on table size */

        if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */

        {                       /* too few codes for k-w bit table */

DEBG1("2 ");

          f -= a + 1;           /* deduct codes from patterns left */

          xp = c + k;

          while (++j < z)       /* try smaller tables up to z bits */

          {

            if ((f <<= 1) <= *++xp)

              break;            /* enough codes to use up j bits */

            f -= *xp;           /* else deduct codes from patterns */

          }

        }

DEBG1("3 ");

        z = 1 << j;             /* table entries for j-bit table */

        /* allocate and link in new table */

        q = (struct huft *)malloc((z + 1)*sizeof(struct huft));

DEBG1("4 ");

        hufts += z + 1;         /* track memory usage */

        *t = q + 1;             /* link to list for huft_free() */

        *(t = &(q->v.t)) = (struct huft *)NULL;

        u[h] = ++q;             /* table starts after link */

DEBG1("5 ");

        /* connect to last table, if there is one */

        if (h)

        {

          x[h] = i;             /* save pattern for backing up */

          r.b = (uch)l;         /* bits to dump before this table */

          r.e = (uch)(16 + j);  /* bits in this table */

          r.v.t = q;            /* pointer to this table */

          j = i >> (w - l);     /* (get around Turbo C bug) */

          u[h-1][j] = r;        /* connect to last table */

        }

DEBG1("6 ");

      }

DEBG("h6c ");

      /* set up table entry in r */

      r.b = (uch)(k - w);

      if (p >= v + n)

        r.e = 99;               /* out of values--invalid code */

      else if (*p < s)

      {

        r.e = (uch)(*p < 256 ? 16 : 15);    /* 256 is end-of-block code */

        r.v.n = *p++;           /* simple code is just the value */

      }

      else

      {

        r.e = (uch)e[*p - s];   /* non-simple--look up in lists */

        r.v.n = d[*p++ - s];

      }

DEBG("h6d ");

      /* fill code-like entries with r */

      f = 1 << (k - w);

      for (j = i >> w; j < z; j += f)

        q[j] = r;

      /* backwards increment the k-bit code i */

      for (j = 1 << (k - 1); i & j; j >>= 1)

        i ^= j;

      i ^= j;

      /* backup over finished tables */

      while ((i & ((1 << w) - 1)) != x[h])

      {

        h--;                    /* don't need to update q */

        w -= l;

      }

DEBG("h6e ");

    }

DEBG("h6f ");

  }

DEBG("huft7 ");

  /* Return true (1) if we were given an incomplete table */

  return y != 0 && g != 1;

}

int huft_free(t)

struct huft *t;         /* table to free */

/* Free the malloc'ed tables built by huft_build(), which makes a linked

   list of the tables it made, with the links in a dummy first entry of

   each table. */

{

  register struct huft *p, *q;

  /* Go through linked list, freeing from the malloced (t[-1]) address. */

  p = t;

  while (p != (struct huft *)NULL)

  {

    q = (--p)->v.t;

    free(p);

    p = q;

  }

  return 0;

}

int inflate_codes(tl, td, bl, bd)

struct huft *tl, *td;   /* literal/length and distance decoder tables */

int bl, bd;             /* number of bits decoded by tl[] and td[] */

/* inflate (decompress) the codes in a deflated (compressed) block.

   Return an error code or zero if it all goes ok. */

{

  register unsigned e;  /* table entry flag/number of extra bits */

  unsigned n, d;        /* length and index for copy */

  unsigned w;           /* current window position */

  struct huft *t;       /* pointer to table entry */

  unsigned ml, md;      /* masks for bl and bd bits */

  register ulg b;       /* bit buffer */

  register unsigned k;  /* number of bits in bit buffer */

  /* make local copies of globals */

  b = bb;                       /* initialize bit buffer */

  k = bk;

  w = wp;                       /* initialize window position */

  /* inflate the coded data */

  ml = mask_bits[bl];           /* precompute masks for speed */

  md = mask_bits[bd];

  for (;;)                      /* do until end of block */

  {

    NEEDBITS((unsigned)bl)

    if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)

      do {

        if (e == 99)

          return 1;

        DUMPBITS(t->b)

        e -= 16;

        NEEDBITS(e)

      } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);

    DUMPBITS(t->b)

    if (e == 16)                /* then it's a literal */

    {

      slide[w++] = (uch)t->v.n;

      if (w == WSIZE)

      {

        flush_output(w);

        w = 0;

      }

    }

    else                        /* it's an EOB or a length */

    {

      /* exit if end of block */

      if (e == 15)

        break;

      /* get length of block to copy */

      NEEDBITS(e)

      n = t->v.n + ((unsigned)b & mask_bits[e]);

      DUMPBITS(e);

      /* decode distance of block to copy */

      NEEDBITS((unsigned)bd)

      if ((e = (t = td + ((unsigned)b & md))->e) > 16)

        do {

          if (e == 99)

            return 1;

          DUMPBITS(t->b)

          e -= 16;

          NEEDBITS(e)

        } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);

      DUMPBITS(t->b)

      NEEDBITS(e)

      d = w - t->v.n - ((unsigned)b & mask_bits[e]);

      DUMPBITS(e)

      /* do the copy */

      do {

        n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e);

#if !defined(NOMEMCPY) && !defined(DEBUG)

        if (w - d >= e)         /* (this test assumes unsigned comparison) */

        {

          memcpy(slide + w, slide + d, e);

          w += e;

          d += e;

        }

        else                      /* do it slow to avoid memcpy() overlap */

#endif /* !NOMEMCPY */

          do {

            slide[w++] = slide[d++];

          } while (--e);

        if (w == WSIZE)

        {

          flush_output(w);

          w = 0;

        }

      } while (n);

    }

  }

  /* restore the globals from the locals */

  wp = w;                       /* restore global window pointer */

  bb = b;                       /* restore global bit buffer */

  bk = k;

  /* done */

  return 0;

}

int inflate_stored()

/* "decompress" an inflated type 0 (stored) block. */

{

  unsigned n;           /* number of bytes in block */

  unsigned w;           /* current window position */

  register ulg b;       /* bit buffer */

  register unsigned k;  /* number of bits in bit buffer */

DEBG("<stor");

  /* make local copies of globals */

  b = bb;                       /* initialize bit buffer */

  k = bk;

  w = wp;                       /* initialize window position */

  /* go to byte boundary */

  n = k & 7;

  DUMPBITS(n);

  /* get the length and its complement */

  NEEDBITS(16)

  n = ((unsigned)b & 0xffff);

  DUMPBITS(16)

  NEEDBITS(16)

  if (n != (unsigned)((~b) & 0xffff))

    return 1;                   /* error in compressed data */

  DUMPBITS(16)

  /* read and output the compressed data */

  while (n--)

  {

    NEEDBITS(8)

    slide[w++] = (uch)b;

    if (w == WSIZE)

    {

      flush_output(w);

      w = 0;

    }

    DUMPBITS(8)

  }

  /* restore the globals from the locals */

  wp = w;                       /* restore global window pointer */

  bb = b;                       /* restore global bit buffer */

  bk = k;

  DEBG(">");

  return 0;

}

int inflate_fixed()

/* decompress an inflated type 1 (fixed Huffman codes) block.  We should

   either replace this with a custom decoder, or at least precompute the

   Huffman tables. */

{

  int i;                /* temporary variable */

  struct huft *tl;      /* literal/length code table */

  struct huft *td;      /* distance code table */

  int bl;               /* lookup bits for tl */

  int bd;               /* lookup bits for td */

  unsigned l[288];      /* length list for huft_build */

DEBG("<fix");

  /* set up literal table */

  for (i = 0; i < 144; i++)

    l[i] = 8;

  for (; i < 256; i++)

    l[i] = 9;

  for (; i < 280; i++)

    l[i] = 7;

  for (; i < 288; i++)          /* make a complete, but wrong code set */

    l[i] = 8;

  bl = 7;

  if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0)

    return i;

  /* set up distance table */

  for (i = 0; i < 30; i++)      /* make an incomplete code set */

    l[i] = 5;

  bd = 5;

  if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1)

  {

    huft_free(tl);

    DEBG(">");

    return i;

  }

  /* decompress until an end-of-block code */

  if (inflate_codes(tl, td, bl, bd))

    return 1;

  /* free the decoding tables, return */

  huft_free(tl);

  huft_free(td);

  return 0;

}

int inflate_dynamic()

/* decompress an inflated type 2 (dynamic Huffman codes) block. */

{

  int i;                /* temporary variables */

  unsigned j;

  unsigned l;           /* last length */

  unsigned m;           /* mask for bit lengths table */

  unsigned n;           /* number of lengths to get */

  struct huft *tl;      /* literal/length code table */

  struct huft *td;      /* distance code table */

  int bl;               /* lookup bits for tl */

  int bd;               /* lookup bits for td */

  unsigned nb;          /* number of bit length codes */

  unsigned nl;          /* number of literal/length codes */

  unsigned nd;          /* number of distance codes */

#ifdef PKZIP_BUG_WORKAROUND

  unsigned ll[288+32];  /* literal/length and distance code lengths */

#else

  unsigned ll[286+30];  /* literal/length and distance code lengths */

#endif

  register ulg b;       /* bit buffer */

  register unsigned k;  /* number of bits in bit buffer */

DEBG("<dyn");

  /* make local bit buffer */

  b = bb;

  k = bk;

  /* read in table lengths */

  NEEDBITS(5)

  nl = 257 + ((unsigned)b & 0x1f);      /* number of literal/length codes */

  DUMPBITS(5)

  NEEDBITS(5)

  nd = 1 + ((unsigned)b & 0x1f);        /* number of distance codes */

  DUMPBITS(5)

  NEEDBITS(4)

  nb = 4 + ((unsigned)b & 0xf);         /* number of bit length codes */

  DUMPBITS(4)

#ifdef PKZIP_BUG_WORKAROUND

  if (nl > 288 || nd > 32)

#else

  if (nl > 286 || nd > 30)

#endif

    return 1;                   /* bad lengths */

DEBG("dyn1 ");

  /* read in bit-length-code lengths */

  for (j = 0; j < nb; j++)

  {

    NEEDBITS(3)

    ll[border[j]] = (unsigned)b & 7;

    DUMPBITS(3)

  }

  for (; j < 19; j++)

    ll[border[j]] = 0;

DEBG("dyn2 ");

  /* build decoding table for trees--single level, 7 bit lookup */

  bl = 7;

  if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)

  {

    if (i == 1)

      huft_free(tl);