CDAccess_CCD.cpp

/* Mednafen - Multi-system Emulator
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

//#define CHECK_CCD_GARBAGE_CUBQ_A
//#define CHECK_CCD_GARBAGE_CUBQ_B
//#define CHECK_CCD_GARBAGE_CUBQ_C
//#define CHECK_CCD_GARBAGE_CUBQ_D

#include "emuware/emuware.h"
#include "../general.h"
#include "../string/trim.h"
#include "CDAccess_CCD.h"
#include <trio/trio.h>

//wrapper to repair gettext stuff
#define _(X) X

#include <limits>
#include <limits.h>
#include <map>

using namespace CDUtility;

static void MDFN_strtoupper(std::string &str)
{
 const size_t len = str.length();

 for(size_t x = 0; x < len; x++)
 {
  if(str[x] >= 'a' && str[x] <= 'z')
  {
   str[x] = str[x] - 'a' + 'A';
  }
 }
}

typedef std::map<std::string, std::string> CCD_Section;

template<typename T>
static T CCD_ReadInt(CCD_Section &s, const std::string &propname, const bool have_defval = false, const int defval = 0)
{
 CCD_Section::iterator zit = s.find(propname);

 if(zit == s.end())
 {
  if(have_defval)
   return defval;
  else
   throw MDFN_Error(0, _("Missing property: %s"), propname.c_str());
 }

 const std::string &v = zit->second;
 int scan_base = 10;
 size_t scan_offset = 0;
 long ret = 0;
 
 if(v.length() >= 3 && v[0] == '0' && v[1] == 'x')
 {
  scan_base = 16;
  scan_offset = 2;
 }

 const char *vp = v.c_str() + scan_offset;
 char *ep = NULL;

 if(std::numeric_limits<T>::is_signed)
  ret = strtol(vp, &ep, scan_base);
 else
  ret = strtoul(vp, &ep, scan_base);

 if(!vp[0] || ep[0])
 {
  throw MDFN_Error(0, _("Property %s: Malformed integer: %s"), propname.c_str(), v.c_str());
 }

 //if(ret < minv || ret > maxv)
 //{
 // throw MDFN_Error(0, _("Property %s: Integer %ld out of range(accepted: %d through %d)."), propname.c_str(), ret, minv, maxv);
 //}

 return ret;
}


CDAccess_CCD::CDAccess_CCD(const std::string& path, bool image_memcache) : img_numsectors(0)
{
 Load(path, image_memcache);
}

void CDAccess_CCD::Load(const std::string& path, bool image_memcache)
{
 FileStream cf(path, FileStream::MODE_READ);
 std::map<std::string, CCD_Section> Sections;
 std::string linebuf;
 std::string cur_section_name;
 std::string dir_path, file_base, file_ext;
 char img_extsd[4] = { 'i', 'm', 'g', 0 };
 char sub_extsd[4] = { 's', 'u', 'b', 0 };

 MDFN_GetFilePathComponents(path, &dir_path, &file_base, &file_ext);

 if(file_ext.length() == 4 && file_ext[0] == '.')
 {
  signed char extupt[3] = { -1, -1, -1 };

  for(int i = 1; i < 4; i++)
  {
   if(file_ext[i] >= 'A' && file_ext[i] <= 'Z')
    extupt[i - 1] = 'A' - 'a';
   else if(file_ext[i] >= 'a' && file_ext[i] <= 'z')
    extupt[i - 1] = 0;
  }

  signed char av = -1;
  for(int i = 0; i < 3; i++)
  {
   if(extupt[i] != -1)
    av = extupt[i];
   else
    extupt[i] = av;
  }

  if(av == -1)
   av = 0;

  for(int i = 0; i < 3; i++)
  {
   if(extupt[i] == -1)
    extupt[i] = av;
  }

  for(int i = 0; i < 3; i++)
  {
   img_extsd[i] += extupt[i];
   sub_extsd[i] += extupt[i];
  }
 }

 //printf("%s %d %d %d\n", file_ext.c_str(), extupt[0], extupt[1], extupt[2]);

 linebuf.reserve(256);

 while(cf.get_line(linebuf) >= 0)
 {
  MDFN_trim(linebuf);

  if(linebuf.length() == 0)	// Skip blank lines.
   continue;

  if(linebuf[0] == '[')
  {
   if(linebuf.length() < 3 || linebuf[linebuf.length() - 1] != ']')
    throw MDFN_Error(0, _("Malformed section specifier: %s"), linebuf.c_str());

   cur_section_name = linebuf.substr(1, linebuf.length() - 2);
   MDFN_strtoupper(cur_section_name);
  }
  else
  {
   const size_t feqpos = linebuf.find('=');
   const size_t leqpos = linebuf.rfind('=');
   std::string k, v;

   if(feqpos == std::string::npos || feqpos != leqpos)
    throw MDFN_Error(0, _("Malformed value pair specifier: %s"), linebuf.c_str());

   k = linebuf.substr(0, feqpos);
   v = linebuf.substr(feqpos + 1);

   MDFN_trim(k);
   MDFN_trim(v);

   MDFN_strtoupper(k);

   Sections[cur_section_name][k] = v;
  }
 }

 {
  CCD_Section& ds = Sections["DISC"];
  unsigned toc_entries = CCD_ReadInt<unsigned>(ds, "TOCENTRIES");
  unsigned num_sessions = CCD_ReadInt<unsigned>(ds, "SESSIONS");
  bool data_tracks_scrambled = CCD_ReadInt<unsigned>(ds, "DATATRACKSSCRAMBLED");

  if(num_sessions != 1)
   throw MDFN_Error(0, _("Unsupported number of sessions: %u"), num_sessions);

  if(data_tracks_scrambled)
   throw MDFN_Error(0, _("Scrambled CCD data tracks currently not supported."));

  //printf("MOO: %d\n", toc_entries);

  for(unsigned te = 0; te < toc_entries; te++)
  {
   char tmpbuf[64];
   trio_snprintf(tmpbuf, sizeof(tmpbuf), "ENTRY %u", te);
   CCD_Section& ts = Sections[std::string(tmpbuf)];
   unsigned session = CCD_ReadInt<unsigned>(ts, "SESSION");
   uint8 point = CCD_ReadInt<uint8>(ts, "POINT");
   uint8 adr = CCD_ReadInt<uint8>(ts, "ADR");
   uint8 control = CCD_ReadInt<uint8>(ts, "CONTROL");
   uint8 pmin = CCD_ReadInt<uint8>(ts, "PMIN");
   uint8 psec = CCD_ReadInt<uint8>(ts, "PSEC");
   //uint8 pframe = CCD_ReadInt<uint8>(ts, "PFRAME");
   signed plba = CCD_ReadInt<signed>(ts, "PLBA");

   if(session != 1)
    throw MDFN_Error(0, "Unsupported TOC entry Session value: %u", session);

   // Reference: ECMA-394, page 5-14
   if(point >= 1 && point <= 99)
   {
	tocd.tracks[point].adr = adr;
	tocd.tracks[point].control = control;
	tocd.tracks[point].lba = plba;
	tocd.tracks[point].valid = true;
   }
   else switch(point)
   {
    default:
	throw MDFN_Error(0, "Unsupported TOC entry Point value: %u", point);
	break;

    case 0xA0:
	tocd.first_track = pmin;
	tocd.disc_type = psec;
	break;

    case 0xA1:
	tocd.last_track = pmin;
	break;

    case 0xA2:
	tocd.tracks[100].adr = adr;
	tocd.tracks[100].control = control;
	tocd.tracks[100].lba = plba;
	tocd.tracks[100].valid = true;
	break;
   }
  }
 }

 //
 // Open image stream.
 {
  std::string image_path = MDFN_EvalFIP(dir_path, file_base + std::string(".") + std::string(img_extsd), true);

  if(image_memcache)
  {
   img_stream.reset(new MemoryStream(new FileStream(image_path, FileStream::MODE_READ)));
  }
  else
  {
   img_stream.reset(new FileStream(image_path, FileStream::MODE_READ));
  }

  uint64 ss = img_stream->size();

  if(ss % 2352)
   throw MDFN_Error(0, _("CCD image size is not evenly divisible by 2352."));

  if(ss > 0x7FFFFFFF)
   throw MDFN_Error(0, _("CCD image is too large."));

  img_numsectors = ss / 2352;  
 }

 //
 // Open subchannel stream
 {
  std::string sub_path = MDFN_EvalFIP(dir_path, file_base + std::string(".") + std::string(sub_extsd), true);
  FileStream sub_stream(sub_path, FileStream::MODE_READ);

  if(sub_stream.size() != (uint64)img_numsectors * 96)
   throw MDFN_Error(0, _("CCD SUB file size mismatch."));

  sub_data.reset(new uint8[(uint64)img_numsectors * 96]);
  sub_stream.read(sub_data.get(), (uint64)img_numsectors * 96);
 }

 CheckSubQSanity();
}

//
// Checks for Q subchannel mode 1(current time) data that has a correct checksum, but the data is nonsensical or corrupted nonetheless; this is the
// case for some bad rips floating around on the Internet.  Allowing these bad rips to be used will cause all sorts of problems during emulation, so we
// error out here if a bad rip is detected.
//
// This check is not as aggressive or exhaustive as it could be, and will not detect all potential Q subchannel rip errors; as such, it should definitely NOT be
// used in an effort to "repair" a broken rip.
//
void CDAccess_CCD::CheckSubQSanity(void)
{
 size_t checksum_pass_counter = 0;
 int prev_lba = INT_MAX;
 uint8 prev_track = 0;

 for(size_t s = 0; s < img_numsectors; s++)
 {
  union
  {
   uint8 full[96];
   struct
   {
    uint8 pbuf[12];
    uint8 qbuf[12];
   };
  } buf;

  memcpy(buf.full, &sub_data[s * 96], 96);

  if(subq_check_checksum(buf.qbuf))
  {
   uint8 adr = buf.qbuf[0] & 0xF;

   if(adr == 0x01)
   {
    uint8 track_bcd = buf.qbuf[1];
    uint8 index_bcd = buf.qbuf[2];
    uint8 rm_bcd = buf.qbuf[3];
    uint8 rs_bcd = buf.qbuf[4];
    uint8 rf_bcd = buf.qbuf[5];
    uint8 am_bcd = buf.qbuf[7];
    uint8 as_bcd = buf.qbuf[8];
    uint8 af_bcd = buf.qbuf[9];

    //printf("%2x %2x %2x\n", am_bcd, as_bcd, af_bcd);

    if(!BCD_is_valid(track_bcd) || !BCD_is_valid(index_bcd) || !BCD_is_valid(rm_bcd) || !BCD_is_valid(rs_bcd) || !BCD_is_valid(rf_bcd) ||
	!BCD_is_valid(am_bcd) || !BCD_is_valid(as_bcd) || !BCD_is_valid(af_bcd) ||
	rs_bcd > 0x59 || rf_bcd > 0x74 || as_bcd > 0x59 || af_bcd > 0x74)
    {
			#ifdef CHECK_CCD_GARBAGE_SUBQ_A
     throw MDFN_Error(0, _("Garbage subchannel Q data detected(bad BCD/out of range): %02x:%02x:%02x %02x:%02x:%02x"), rm_bcd, rs_bcd, rf_bcd, am_bcd, as_bcd, af_bcd);
			#endif
    }
    else
    {
     int lba = ((BCD_to_U8(am_bcd) * 60 + BCD_to_U8(as_bcd)) * 75 + BCD_to_U8(af_bcd)) - 150;
     uint8 track = BCD_to_U8(track_bcd);

			#ifdef CHECK_CCD_GARBAGE_SUBQ_B
     if(prev_lba != INT_MAX && abs(lba - prev_lba) > 100)
      throw MDFN_Error(0, _("Garbage subchannel Q data detected(excessively large jump in AMSF)"));
			#endif

		 #ifdef CHECK_CCD_GARBAGE_SUBQ_C
     if(abs(lba - (int)s) > 100) //zero 19-jun-2015 a bit of a sneaky signed/unsigned fixup here
      throw MDFN_Error(0, _("Garbage subchannel Q data detected(AMSF value is out of tolerance)"));
		 #endif

     prev_lba = lba;

		 #ifdef CHECK_CCD_GARBAGE_SUBQ_D
     if(track < prev_track)
      throw MDFN_Error(0, _("Garbage subchannel Q data detected(bad track number)"));
		 #endif
     //else if(prev_track && track - pre

     prev_track = track;
    }
    checksum_pass_counter++;
   }
  }
 }

 //printf("%u/%u\n", checksum_pass_counter, img_numsectors);
}

CDAccess_CCD::~CDAccess_CCD()
{

}

void CDAccess_CCD::Read_Raw_Sector(uint8 *buf, int32 lba)
{
 if(lba < 0)
 {
  synth_udapp_sector_lba(0xFF, tocd, lba, 0, buf);
  return;
 }

 if((size_t)lba >= img_numsectors)
 {
  synth_leadout_sector_lba(0xFF, tocd, lba, buf);
  return;
 }

 img_stream->seek(lba * 2352, SEEK_SET);
 img_stream->read(buf, 2352);

 subpw_interleave(&sub_data[lba * 96], buf + 2352);
}

bool CDAccess_CCD::Fast_Read_Raw_PW_TSRE(uint8* pwbuf, int32 lba) const noexcept
{
 if(lba < 0)
 {
  subpw_synth_udapp_lba(tocd, lba, 0, pwbuf);
  return true;
 }

 if((size_t)lba >= img_numsectors)
 {
  subpw_synth_leadout_lba(tocd, lba, pwbuf);
  return true;
 }

 subpw_interleave(&sub_data[lba * 96], pwbuf);

 return true;
}

void CDAccess_CCD::Read_TOC(CDUtility::TOC *toc)
{
 *toc = tocd;
}