/*
 *  This Loader Module is written by Ilfak Guilfanov and
 *                        rewriten by Yury Haron
 *
 */
/*
  L O A D E R  for Netware Loadable Module (NLM)
*/

#include <stddef.h>
#include "../idaldr.h"
#include "nlm.h"
#include <typeinf.hpp>

#pragma pack(push, 1)

//--------------------------------------------------------------------------
//
//      check input file format. if recognized, then return 1
//      and fill 'fileformatname'.
//      otherwise return 0
//
static int idaapi accept_file(
        qstring *fileformatname,
        qstring *processor,
        linput_t *li,
        const char *)
{
  char magic[NLM_MAGIC_SIZE];

  if ( qlread(li, magic, sizeof(magic)) != sizeof(magic )
    || memcmp(magic, NLM_MAGIC, sizeof(magic)) != 0 )
  {
    return 0;
  }

  *fileformatname = "Netware Loadable Module (NLM)";
  *processor      = "metapc";
  return f_NLM;
}

//--------------------------------------------------------------------------
NORETURN static void _errstruct(int lnnum)
{
  loader_failure("Bad file structure or read error (line %d)", lnnum);
}
#define errstruct()  _errstruct(__LINE__)

//--------------------------------------------------------------------------
//lint -e{958} padding needed
static struct local_data
{
  struct unp_data
  {
    FILE    *fo;
    uint32  pos, size;
    uchar   *buff;
    ushort  b_pos, b_val;
  };

  linput_t *li;
  nlmexe_t nlm;
  union
  {
    char buf[MAXSTR];
    unp_data unp;
  }; //lint !e958 padding is required to align members
  ea_t start, cbase, csize, dbase, dsize;
  netnode impnode;
} lc;

//--------------------------------------------------------------------------
static int mread(void *buf, size_t size)
{
  if ( qlread(lc.li, buf, size) == size )
    return 0;
  if ( ask_yn(ASKBTN_NO,
              "HIDECANCEL\n"
              "Read error or bad file structure. Continue loading?") <= ASKBTN_NO )
  {
    loader_failure();
  }
  return 1;
}

//--------------------------------------------------------------------------
static int getstr(void)
{
  uchar len;
#if MAXSTR < 256
#error
#endif

  if ( mread(&len, sizeof(len)) || (len && mread(lc.buf, len)) )
    return 1;
  lc.buf[len] = '\0';
  return 0;
}

//----------------------------------------------------------------------
static void set_reloc(ushort sel, ea_t fixaddr, ea_t toea, bool self_flag)
{
  sval_t displ = int32(get_dword(fixaddr));

  fixup_data_t fd(FIXUP_OFF32);
  fd.off = toea;
  fd.sel = sel;
  if ( sel == 3 )
  {
    fd.set_extdef();
    fd.displacement = displ;
  }
  if ( self_flag )
    toea -= fixaddr;
  put_dword(fixaddr, uint32(toea + displ));
  fd.set(fixaddr);
}

//----------------------------------------------------------------------
static void add_imports(void)
{
  if ( lc.nlm.impoff == 0 || lc.nlm.impnum == 0 )
    return;
  uint32 i = lc.nlm.impnum;
  msg("Creating imported names and relocating it...\n");
  lc.impnode.create(LDR_NODE);
  qlseek(lc.li, lc.nlm.impoff, SEEK_SET);
  ea_t ebase = lc.start;
  ea_t eend  = ebase + (i * sizeof(int32));
  uint64 fsize = qlsize(lc.li);
  if ( lc.nlm.impoff >= fsize )
    loader_failure("Bad import offset");
  uint64 rest = fsize - lc.nlm.impoff;
  if ( !is_mul_ok<uint32>(i, sizeof(int32))
    || eend <= ebase
    || qoff64_t(i)*2 > rest ) // each name requires at least 2 bytes
  {
    loader_failure("Bad import count");
  }

  set_selector(3, 0);
  if ( add_segm(3, ebase, eend, NAME_EXTERN, NULL) )
  {
    segment_t *ps = getseg(ebase);
    ps->type = SEG_XTRN;
    ps->update();
  }
  else
  {
    loader_failure();
  }

  uchar ss = inf_get_specsegs();
  for ( ; i; i--, ebase += ss )
  {
    if ( getstr() )
      break;
    show_addr(ebase);
    set_name(ebase, lc.buf, SN_NOCHECK | SN_PUBLIC | SN_IDBENC);
    if ( ss == 8 )
      put_qword(ebase, 0);
    else
      put_dword(ebase, 0);
    if ( lc.impnode )
      netnode(lc.impnode).supset_ea(ebase, lc.buf);
    uint32 fnum;
    if ( mread(&fnum, sizeof(fnum)) )
    {
FORCE_END:
      if ( (ebase += ss) < eend )
        set_segm_end(ebase, ebase, SEGMOD_KILL);
      return;
    }
    int sff = 0;
    while ( fnum-- )
    {
      uint32 ent;
      if ( mread(&ent, sizeof(ent)) )
        goto FORCE_END;
      ea_t ea, sz;
      bool self = (ent & 0x80000000) == 0;
      if ( ent & 0x40000000 )
      {
        ea = lc.cbase;
        sz = lc.csize;
      }
      else
      {
        ea = lc.dbase;
        sz = lc.dsize;
      }
      ent &= ~0xC0000000;
      if ( ent >= sz )
      {
        msg("Skip reference to extern '%s' with illegal offset 0x%X\n",
            lc.buf, ent);
      }
      else
      {
        set_reloc(3, ea + ent, ebase, self);
        if ( sff == 0 && self )
        {
          ++sff;
          add_func(ebase, ebase+ss-1);
        }
      }
    }
  }
}

//--------------------------------------------------------------------------
static void add_fixups(void)
{
  if ( lc.nlm.fixupoff == 0 || lc.nlm.fixupnum == 0 )
    return;
  uint32 i = lc.nlm.fixupnum;
  msg("Applying internal fixup records...\n");
  qlseek(lc.li, lc.nlm.fixupoff, SEEK_SET);

  validate_array_count_or_die(lc.li, i, 4, "Number of fixups", lc.nlm.fixupoff);
  while ( i-- != 0 )
  {
    uint32 ent;
    if ( mread(&ent, sizeof(ent)) )
      break;
    ea_t base, toea;
    asize_t size;
    if ( ent & 0x40000000 )
    {
      base = lc.cbase;
      size = lc.csize;
    }
    else
    {
      base = lc.dbase;
      size = lc.dsize;
    }
    ushort sel;
    if ( ent & 0x80000000 )
    {
      toea = lc.cbase;
      sel = 1;
    }
    else
    {
      toea = lc.dbase;
      sel = 2;
    }
    ent &= ~0xC0000000;
    if ( ent >= size || !toea )
      msg("Skip invalid relocation for offset 0x%X (to base %a)\n", ent, toea);
    else
      set_reloc(sel, ent + base, toea, 0);
  }
}

//--------------------------------------------------------------------------
static void add_exports_and_publics(void)
{
  uint32 i, foff;
  int pfl;

  for ( pfl = 0, foff = lc.nlm.expoff, i = lc.nlm.expnum;
        pfl < 2;
        pfl++, foff = lc.nlm.puboff, i = lc.nlm.pubnum )
  {
    if ( foff == 0 || i == 0 )
      continue;
    msg("Applying %s names...\n", pfl ? "public" : "exported");
    qlseek(lc.li, foff, SEEK_SET);
    validate_array_count_or_die(lc.li, i, 4,
                                pfl ? "Number of publics" : "Number of exports",
                                foff);
    while ( i-- != 0 )
    {
      bool flag;
      ea_t ea;
      CASSERT(sizeof(flag) == 1);
      if ( !pfl )
      {
        if ( getstr() || mread(&ea, sizeof(uint32)) )
          break;
        flag = (ea & 0x80000000) != 0;
      }
      else if ( mread(&flag, sizeof(flag))
             || mread(&ea, sizeof(uint32))
             || getstr() )
      {
        break;
      }
      ea &= ~0xC0000000L;
      ea_t base;
      asize_t size;
      if ( flag )
      {
        base = lc.cbase;
        size = lc.csize;
      }
      else
      {
        base = lc.dbase;
        size = lc.dsize;
      }
      if ( ea >= size )
      {
        msg("Skip name '%s' with illegal offset (0x%a)\n", lc.buf, ea);
      }
      else
      {
        ea += base;
        add_entry(ea, ea, lc.buf, flag, AEF_IDBENC);
      }
    }
  }
}

//--------------------------------------------------------------------------
static int LoadMsgString(void)
{
  int c, i;
  for ( i = 0; i < sizeof(lc.buf)-1; i++ )
  {
    if ( (c = qlgetc(lc.li)) == EOF )
      return 0;
    if ( !c )
      break;
    if ( c == 0xFF )
    {
      c = '.';
    }
    else if ( c < ' ' )
    {
      static const char rpts[] = "\t\n\r\a\v\f";
      static const char rptc[] = "tnravf";
      const char *p = strchr(rpts, c);
      if ( p )
      {
        if ( i == sizeof(lc.buf)-2 )
          break;
        lc.buf[i++] = '\\';
        c = (int)(uchar)rptc[(int)(p-rpts)];
      }
    }
    lc.buf[i] = (char)c;
  }
  lc.buf[i] = '\0';
  return 1;
}

//--------------------------------------------------------------------------
static uint32 addSpecialComment(void)
{
  uchar vp = 0, cp = 0;
  uint32 mp = 0;
  qoff64_t pos = qltell(lc.li);
  ea_t loadbase = lc.nlm.codeoff;
  if ( lc.nlm.datalen && loadbase > lc.nlm.dataoff )
    loadbase = lc.nlm.dataoff;
  if ( loadbase > 0x1000 )
    loadbase = 0x1000;

  while ( pos + 12 < loadbase )
  {
    if ( mread(lc.buf, 12) )
      break;
    if ( !mp && !memcmp(lc.buf, "MeSsAgEs", 8) )
    {
      mp = pos + 8;
      pos += 0x7C;
      goto repos;
    }
    if ( !vp && !memcmp(lc.buf, "VeRsIoN#", 8) )
    {
      if ( mread(&lc.buf[12], 32-12) )
        break;
      ++vp;
      pos += 32 - 1;
      qsnprintf(&lc.buf[32], sizeof(lc.buf)-32, "%u.%02u%c (%02u.%02u.%04u)",
              *(uint32 *)&lc.buf[8], (uchar)lc.buf[8+4],
              *(uint32 *)&lc.buf[8+8] ? (char)(lc.buf[8+8] + ('A'-1)) : ' ',
              (uchar)lc.buf[8+20], (uchar)lc.buf[8+16],
              *(ushort *)&lc.buf[8+12]);
      add_pgm_cmt("Version                : %s", &lc.buf[32]);
      goto check;
    }
    if ( !cp && !memcmp(lc.buf, "CoPyRiGhT=", 10) )
    {
      pos += 10;
      pos += (uchar)lc.buf[10];
      qlseek(lc.li, -2L, SEEK_CUR);
      if ( getstr() )
        break;
      add_pgm_cmt("Copyright              : %s", lc.buf);
      ++cp;
      goto check;
    }
    if ( !memcmp(lc.buf, "CuStHeAd", 8) )
    {
      pos += 8;
      pos += *(uint32 *)&lc.buf[8];
      goto repos;
    }
check:
    if ( mp && vp && cp )
      break;
    ++pos;
repos:
    qlseek(lc.li, pos, SEEK_SET);
  }
  return mp;
}

//--------------------------------------------------------------------------
static void addComments(int flg)
{
  uint32 clst = (uint32)-1, msgpos = 0;
  char *cl1 = NULL;
  char *cl2 = NULL;

  create_filename_cmt();
  qlseek(lc.li, NLM_MODNAMOFF, SEEK_SET);
  if ( lc.nlm.fname[0] )
    add_pgm_cmt("Module Name            : %.12s", lc.nlm.fname);
  if ( !getstr() )
  {
    add_pgm_cmt("Description            : %s", lc.buf);
    qlseek(lc.li, 1, SEEK_CUR);
    if ( mread(&clst, sizeof(clst)) )
    {
      clst = (uint32)-1;
    }
    else
    {
      qlseek(lc.li, 0xD-sizeof(clst), SEEK_CUR);
      if ( !getstr() )
      {
        cl1 = qstrdup(lc.buf);
        qlseek(lc.li, 1, SEEK_CUR);
        if ( !getstr() )
        {
          cl2 = qstrdup(lc.buf);
          msgpos = addSpecialComment();
        }
      }
    }
  }
  add_pgm_cmt("File Format Version    : %08Xh%s", lc.nlm.version,
              (lc.nlm.version & NLM_COMPRESSED) ? " (compressed)" : "");
  {
    static const char *const tt[15] =
    {
      "Generic",
      "LAN Driver",
      "Disk Driver",
      "Name Space",
      "Patch/Utility",
      "Mirrored Server Link",
      "OS",
      "High OS",
      "Host Adapter",
      "Custom Device",
      "FS Engine",
      "Real Mode",
      "OS",                // duplicate 6
      "Platform Support",
      "Unknown"
    };
    int type = (int)lc.nlm.modType;
    if ( lc.nlm.modType > 14 )
      type = 14;
    add_pgm_cmt("Module type            : %s (%d)", tt[type], type);
  }
  if ( lc.nlm.bssSize )
    add_pgm_cmt("Unitialized data size  : %08Xh", lc.nlm.bssSize);
  if ( lc.nlm.custoff && lc.nlm.custlen )
    add_pgm_cmt("Custom data            : off=%08Xh len=%08Xh",
                                            lc.nlm.custoff, lc.nlm.custlen);
  lc.buf[0]= '\0';
  if ( lc.nlm.flags )
  {
    static const char *const ff[4] =
    {
      "reentrant",
      "multiply loadable",
      "synchronize",
      "pseudo-preemptable"
    };
    char *ptr = lc.buf;
    char *end = lc.buf + sizeof(lc.buf);
    int cn = 0;
    APPCHAR(ptr, end, ' ');
    APPCHAR(ptr, end, '(');
    for ( int i = 0; i < 4; i++ )
    {
      if ( lc.nlm.flags & (1 << i) )
      {
        if ( cn )
        {
          APPCHAR(ptr, end, ',');
          APPCHAR(ptr, end, ' ');
        }
        ++cn;
        APPEND(ptr, end, ff[i]);
      }
    }
    if ( cn )
      APPCHAR(ptr, end, ')');
    else
      ptr = lc.buf;
    APPZERO(ptr, end);
  }
  add_pgm_cmt("Flags                  : %08Xh%s", lc.nlm.flags, lc.buf);
  if ( clst != (uint32)-1 )
    add_pgm_cmt("CLIB Stack Size        : %08Xh", clst);
  if ( cl1 )
  {
    if ( *cl1 )
      add_pgm_cmt("CLIB Screen Name       : %s", cl1);
    qfree(cl1);
  }
  if ( cl2 )
  {
    if ( *cl2 )
      add_pgm_cmt("CLIB Thread Name       : %s", cl2);
    qfree(cl2);
  }
  if ( lc.nlm.autoliboff && lc.nlm.autolibnum )
  {
    qlseek(lc.li, lc.nlm.autoliboff, SEEK_SET);
    for ( uint i = 0; i < lc.nlm.autolibnum; i++ )
    {
      if ( getstr() )
        break;
      add_pgm_cmt("Referenced Modules     : '%s'", lc.buf);
      if ( lc.impnode )
      {
        char *p1, *p2;
        for ( p1 = lc.buf; p1 && *trim(p1); p1 = p2 )
        {
          if ( (p2 = strchr(p1, '|')) != NULL )
          {
            *p2++ = '\0';
            if ( !*trim(p1) )
              continue;
          }
          import_module(p1, NULL, lc.impnode, NULL, "netware");
        }
      }
    }
  }

  if ( !msgpos )
    return;

  qlseek(lc.li, msgpos, SEEK_SET);
  if ( mread(lc.buf, 0x7C-8) )
    return;

  uint32 id = *(uint32 *)&lc.buf[0x60-8];
  if ( id )
    add_pgm_cmt("Product ID             : %08Xh", id);
  id = *(uint32 *)&lc.buf[0];
  if ( id )
    add_pgm_cmt("Language ID            : %u", id);
  id = *(uint32 *)&lc.buf[0x34-8];
  if ( id )
    add_pgm_cmt("Shared Data            : off=%08Xh, size=%08Xh",
                                              *(uint32 *)&lc.buf[0x30-8], id);
  id = *(uint32 *)&lc.buf[0x2C-8];
  if ( id )
  {
    add_pgm_cmt("Shared Code            : off=%08Xh, size=%08Xh",
                                            *(uint32 *)&lc.buf[0x28-8], id);
    add_pgm_cmt("Shared Start Procedure : off=%08Xh",
                                              *(uint32 *)&lc.buf[0x58-8]);
    add_pgm_cmt("Shared Exit Procedure  : off=%08Xh",
                                              *(uint32 *)&lc.buf[0x5C-8]);
  }
  id = *(uint32 *)&lc.buf[0x1C-8];
  if ( id )
    add_pgm_cmt("Help                   : off=%08Xh, size=%08Xh",
                                              *(uint32 *)&lc.buf[0x18-8], id);
  id = *(uint32 *)&lc.buf[0x24-8];
  if ( id )
    add_pgm_cmt("RPC & BAG              : off=%08Xh, size=%08Xh",
                                            *(uint32 *)&lc.buf[0x20-8], id);
  id = *(uint32 *)&lc.buf[0x10-8];

  if ( id )
  {
    add_pgm_cmt("Message                : off=%08Xh, size=%08Xh",
                                    msgpos = *(uint32 *)&lc.buf[0xC-8], id);

    if ( !flg )
      return;

    uint32 mlng, mcnt;
    qlseek(lc.li, msgpos + 0x6A, SEEK_SET);
    if ( mread(&mlng, sizeof(mlng)) || mread(&mcnt, sizeof(mcnt)) )
      return;

    add_pgm_cmt("Message Language       : %08Xh", mlng);
    msgpos += 0x76;
    for ( clst = 0; clst < mcnt; clst++ )
    {
      qlseek(lc.li, msgpos + qoff64_t(clst)*4, SEEK_SET);
      if ( mread(&mlng, sizeof(mlng)) )
        break;
      qlseek(lc.li, msgpos + mlng, SEEK_SET);
      if ( !LoadMsgString() )
        break;
      add_pgm_cmt("   %08X : %s", clst, lc.buf);
    }
// 4C - Shared Exported Symbols
// 44 - Shared Imported Symbols
// 3C - Shared Fixups
// 54 - Shared Debug Records
  }
}

//--------------------------------------------------------------------------
static void load_image(void)
{
  uint32 lend = 0;
  uint32 addbss = 0;

  qoff64_t off = lc.nlm.codeoff;
  if ( off != 0 )
  {
    lend = lc.nlm.codelen;
    if ( lend != 0 )
    {
      lc.csize = lend;
      lc.cbase = lc.start;
    }
  }
  for ( int i = 1; ; )
  {
    const char *pn, *pc;
    segment_t s;
    s.start_ea = lc.start;
    s.end_ea   = lc.start;
    s.align    = saRel4K;
    s.bitness  = 1;
    s.comb     = scPub;
    s.sel      = i;
    if ( i == 1 )
    {
      s.type  = SEG_CODE;
      pn      = NAME_BSS;
      pc      = CLASS_CODE;
    }
    else
    {
      if ( lend == 0 )
      {
        pn = NAME_BSS;
        pc = CLASS_BSS;
      }
      else
      {
        pn = NAME_DATA;
        pc = CLASS_DATA;
      }
      if ( lend != 0 || addbss )
      {
        s.type = SEG_DATA;
        lc.dbase = lc.start;
        lc.dsize = lend;
      }
    }
    if ( lend == 0 && !addbss )
    {
      s.type = SEG_NULL;
      lc.start += 0x1000;
    }
    else
    {
      if ( lend != 0 )
      {
        s.end_ea += lend;
        uint64 fsize = qlsize(lc.li);
        if ( s.end_ea < s.start_ea || off > fsize || s.size() > fsize-off )
          loader_failure("Truncated input file");
        file2base(lc.li, off, s.start_ea, s.end_ea, FILEREG_PATCHABLE);
      }
      s.end_ea += addbss;
      lc.start = (s.end_ea + 0xFFF) & ~0xFFF;
    }
    set_selector(s.sel, 0);
    if ( !add_segm_ex(&s, pn, pc, ADDSEG_NOSREG | ADDSEG_SPARSE) )
      loader_failure();
//-
    if ( ++i > 2 )
      break;
    addbss = lc.nlm.bssSize;
    lend = ((off = lc.nlm.dataoff) == 0) ? 0 : lc.nlm.datalen;
  }
}

//--------------------------------------------------------------------------
static void Unpack(void);
//--------------------------------------------------------------------------
//
//      load file into the database.
//
void idaapi load_file(linput_t *li, ushort neflag, const char * /*fileformatname*/)
{
  set_processor_type("metapc", SETPROC_LOADER);
  add_til("nlm", ADDTIL_DEFAULT);
  inf_set_lflags(inf_get_lflags() | LFLG_PC_FLAT);

  if ( qlread(lc.li = li, &lc.nlm, sizeof(lc.nlm)) != sizeof(lc.nlm) )
    errstruct();
  if ( lc.nlm.version & NLM_COMPRESSED )
    Unpack();

  lc.start = to_ea(inf_get_baseaddr(), 0);
  memset(&lc.cbase, 0, sizeof(local_data) - qoffsetof(local_data, cbase));

  load_image();
  set_default_dataseg(2);

  if ( lc.nlm.startIP < lc.csize )
  {
    uval_t bip = lc.cbase + lc.nlm.startIP;
    inf_set_start_cs(1);
    inf_set_start_ip(bip);
    add_entry(bip, bip, "nlm_start", 1);
  }
  if ( (lc.nlm.endIP || lc.nlm.startIP) && lc.nlm.endIP < lc.csize )
  {
    uval_t eip = lc.cbase + lc.nlm.endIP;
    add_entry(eip, eip, "nlm_terminate", 1);
  }
  if ( lc.nlm.auxIP && lc.nlm.auxIP < lc.csize )
  {
    uval_t aip = lc.cbase + lc.nlm.auxIP;
    add_entry(aip, aip, "nlm_check_unload", 1);
  }

//  inf.nametype   =  NM_EA;
//  inf.s_prefflag &= ~PREF_SEGADR;
//  inf.start_ss = BADSEL;
//  inf.start_sp = BADADDR;
  inf_set_specsegs(inf_is_64bit() ? 8 : 4);

  add_imports();
  add_exports_and_publics();
  add_fixups();
  addComments(neflag & NEF_RSCS);
  if ( lc.impnode )
    import_module("nlm_root", NULL, lc.impnode, NULL, "netware");
  inf_set_lowoff(inf_get_min_ea());

  if ( lc.li != li )
    close_linput(lc.li);  // close & delete tmp (unpack) file

  split_sreg_range(inf_get_start_ea(), PH.reg_data_sreg, 2, SR_autostart, true);
}

//----------------------------------------------------------------------
//
//      LOADER DESCRIPTION BLOCK
//
//----------------------------------------------------------------------
loader_t LDSC =
{
  IDP_INTERFACE_VERSION,
  0,                            // loader flags
//
//      check input file format. if recognized, then return 1
//      and fill 'fileformatname'.
//      otherwise return 0
//
  accept_file,
//
//      load file into the database.
//
  load_file,
//
//      create output file from the database.
//      this function may be absent.
//
  NULL,
//      take care of a moved segment (fix up relocations, for example)
  NULL,
  NULL,
};

//===============unpack=====================================================
NORETURN static void memerr(void)
{
  nomem("NLM-loader (for unpacking)");
}

//==========================================================================
#define OUTSIZE 8192  // 2**13

static void unp_process(void);

static void Unpack(void)
{
  uint32 fsize;
  FILE *fo;

  CASSERT(sizeof(lc) - qoffsetof(local_data, nlm) > 0x196);   //-V658 value is being subtracted from the unsigned
  CASSERT(qoffsetof(local_data,buf) == qoffsetof(local_data,nlm)+sizeof(lc.nlm));

  if ( qlread(lc.li, lc.buf, 0x196-sizeof(lc.nlm)) != (0x196-sizeof(lc.nlm)) )
    errstruct();
  if ( lc.buf[0x190 - sizeof(lc.nlm )] != 1
    || lc.buf[0x191 - sizeof(lc.nlm)] != 10 )
  {
    loader_failure("Unknown compressing method");
  }
  if ( (fsize = *((uint32 *)&lc.buf[0x192 - sizeof(lc.nlm)])) <= 0x190 )
    errstruct();

  if ( (fo = qtmpfile()) == NULL )
    loader_failure("Cannot create temporary file for decompressing");
  qfwrite(fo, &lc.nlm, 0x190); //lint !e426

  lc.unp.buff = (uchar *)qalloc(OUTSIZE);
  if ( lc.unp.buff == NULL )
    memerr();
  lc.unp.b_pos = 0x190;
  lc.unp.pos   = 0x190;
  lc.unp.b_val = 0;
  lc.unp.fo    = fo;
  lc.unp.size  = fsize;

  msg("Decompressing module...");
  unp_process();

  qfree(lc.unp.buff);
  if ( qflush(lc.unp.fo) || ferror(lc.unp.fo) || feof(lc.unp.fo) )
    loader_failure("disk full or cannot write temporary file");
//  qlseek(fo, sizeof(nlm), SEEK_SET);
  msg("Ok\n");
  lc.li = make_linput(lc.unp.fo);
}

//=========================================================================
struct record
{
  record *left;
  union
  {
    record *right;
    uchar data;
  };
};

//=====================================================================
static void putUnpByte(uchar data)
{
  qfputc(data, lc.unp.fo);
  ++lc.unp.pos;
  lc.unp.buff[lc.unp.b_pos] = data;
  if ( ++lc.unp.b_pos == OUTSIZE )
    lc.unp.b_pos = 0;
}

//=====================================================================
static void putUnpRepeatBlk(ushort off, ushort sizeBlk)
{
  if ( !off || !sizeBlk || (uint32)off >= lc.unp.pos )
    errstruct();
  int pos = lc.unp.b_pos - off;
  if ( pos < 0 )
    pos += OUTSIZE;
  while ( true )
  {
    putUnpByte(lc.unp.buff[pos]);
    if ( --sizeBlk == 0 )
      break;
    if ( ++pos == OUTSIZE )
      pos = 0;
  }
}

//=====================================================================
inline ushort nextbyte(void)
{
  uchar i;
  if ( qlread(lc.li, &i, sizeof(i)) != sizeof(i) )
    errstruct();
  return i;
}

//=====================================================================
ushort getNbit(int cnt)
{
  ushort res = 0;
  ushort val = lc.unp.b_val;
  int i = cnt;
  do
  {
    if ( val <= 0xFF )
      val = nextbyte() | 0x8000;
    res >>= 1;
    if ( val & 1 )
      res |= 0x8000;
    val >>= 1;
  } while ( --i != 0 );
  lc.unp.b_val = val;
  return res >> (16-cnt);
}

//=====================================================================
static int getbit(void)
{
  if ( lc.unp.b_val <= 0xFF )
    lc.unp.b_val = nextbyte() | 0x8000;
  int i = lc.unp.b_val & 1;
  lc.unp.b_val >>= 1;
  return i;
}

//=====================================================================
inline uchar getbyte(void)
{
  if ( lc.unp.b_val <= 0xFF )
    return (uchar)nextbyte();
  return (uchar)getNbit(8);
}

//=====================================================================
static uchar extractByte(const record *p)
{
  while ( p->left )
    p = getbit() ? p->right : p->left;
  return p->data;
}

//=====================================================================
static void free_record(record *p)
{
  if ( p->left )
  {
    free_record(p->left);
    free_record(p->right);
  }
  qfree(p);
}

//=====================================================================
static record *load_record(void)
{
  record *p = (record *)qalloc(sizeof(record));
  if ( p == NULL )
    memerr();
  if ( getbit() )
  {
    p->left = NULL;
    p->data = getbyte();
  }
  else
  {
    p->left  = load_record();
    p->right = load_record();
  }
  return p;
}

//=====================================================================
static void unp_process(void)
{
  record *rOne = load_record();
  record *rKey = load_record();
  record *rPos = load_record();

  while ( lc.unp.pos < lc.unp.size )
  {
    if ( getbit() )
    {
      putUnpByte(extractByte(rOne));
      continue;
    }
    ushort data = extractByte(rKey);
    switch ( data )
    {
      case 255:
        {
          uint32 cnt = 0;
          lc.unp.b_val = 0;
          int i = 8;
          do
            putUnpByte((uchar)nextbyte());
          while ( --i != 0 );
          do
          {
            uchar c;
            putUnpByte(c = (uchar)nextbyte());
            cnt |= ((uint32)c << (i*8));
          } while ( ++i < 4 );
          while ( cnt-- )
            putUnpByte((uchar)nextbyte());
        }
        break;

      case 254:
        data = getNbit(13);
        // fallthrough
      default:
        {
          ushort off = getNbit(5);
          off |=((ushort)extractByte(rPos) << 5);
          putUnpRepeatBlk(off, data);
        }
        break;
    }
  } // while
  if ( lc.unp.pos != lc.unp.size )
    errstruct();

  free_record(rOne);
  free_record(rKey);
  free_record(rPos);
}

#pragma pack(pop)