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#include "Cluster.h"
#include "read.h"
#include "global_elements.h"
#include <winsock.h>
// returns bytes read. 0 means EOF
uint64_t nsmkv::ReadBlockGroup(nsmkv::MKVReader *reader, uint64_t size, nsmkv::Block &block, uint64_t *allowed_track_numbers, size_t num_allowed_track_numbers)
{
uint64_t total_bytes_read=0;
while (size)
{
uint64_t ebml_start_position = reader->Tell(); // need this for recording the block binary start position
ebml_node node;
uint64_t bytes_read = read_ebml_node(reader, &node);
if (bytes_read == 0)
return 0;
// benski> checking bytes_read and node.size separately prevents possible integer overflow attack
if (bytes_read > size)
return 0;
total_bytes_read+=bytes_read;
size-=bytes_read;
if (node.size > size)
return 0;
total_bytes_read+=node.size;
size-=node.size;
switch(node.id)
{
case mkv_blockgroup_referenceblock:
{
int64_t val;
if (read_signed(reader, node.size, &val) == 0)
return 0;
#ifdef WA_VALIDATE
printf(" Reference Block: %I64d\n", val);
#endif
block.reference_block = val;
}
break;
case mkv_blockgroup_block:
{
#ifdef WA_VALIDATE
printf(" Block: binary size %I64u\n", node.size);
#endif
if (ReadBlockBinary(reader, node.size, block.binary, allowed_track_numbers, num_allowed_track_numbers) == 0)
return 0;
}
break;
case mkv_blockgroup_blockduration:
{
uint64_t val;
if (read_unsigned(reader, node.size, &val) == 0)
return 0;
#ifdef WA_VALIDATE
printf(" Block Duration: %I64u\n", val);
#endif
block.block_duration = val;
}
break;
default:
nsmkv::ReadGlobal(reader, node.id, node.size);
}
}
return total_bytes_read;
}
// returns bytes read. 0 means EOF
uint64_t nsmkv::ReadCluster(nsmkv::MKVReader *reader, uint64_t size, nsmkv::Cluster &cluster)
{
uint64_t total_bytes_read=0;
while (size)
{
ebml_node node;
uint64_t bytes_read = read_ebml_node(reader, &node);
if (bytes_read == 0)
return 0;
// benski> checking bytes_read and node.size separately prevents possible integer overflow attack
if (bytes_read > size)
return 0;
total_bytes_read+=bytes_read;
size-=bytes_read;
if (node.size > size)
return 0;
total_bytes_read+=node.size;
size-=node.size;
switch(node.id)
{
case mkv_cluster_timecode:
{
uint64_t val;
if (read_unsigned(reader, node.size, &val) == 0)
return 0;
#ifdef WA_VALIDATE
printf(" Time Code: %I64u\n", val);
cluster.time_code_found = true;
#endif
cluster.time_code = val;
}
break;
case mkv_cluster_blockgroup:
{
#ifdef WA_VALIDATE
printf(" Block Group\n");
#endif
Block block;
if (ReadBlockGroup(reader, node.size, block, 0, 0) == 0)
return 0;
}
break;
case mkv_cluster_simpleblock:
{
#ifdef WA_VALIDATE
printf(" Simple Block, size: %I64u\n", node.size);
#endif
BlockBinary bbinary;
if (ReadBlockBinary(reader, node.size, bbinary, 0, 0) == 0)
return 0;
// fseek64(f, node.size, SEEK_CUR);
}
break;
default:
ReadGlobal(reader, node.id, node.size);
}
}
return total_bytes_read;
}
uint64_t nsmkv::ReadBlockBinary(nsmkv::MKVReader *reader, uint64_t size, nsmkv::BlockBinary &binary, uint64_t *allowed_track_numbers, size_t num_allowed_track_numbers)
{
uint64_t orig_size = size;
size_t bytes_read = (size_t)read_vint(reader, &binary.track_number);
if (!bytes_read)
return 0;
size-=bytes_read;
bool allowed_track=false;
if (num_allowed_track_numbers == (size_t)-1)
{
allowed_track=true;
}
else
{
for (size_t i=0;i!=num_allowed_track_numbers;i++)
{
if (binary.track_number == allowed_track_numbers[i])
{
allowed_track=true;
break;
}
}
}
#ifdef WA_VALIDATE
// if we are validating the file, force all tracks to go thru
allowed_track = true;
#endif
if (allowed_track && size >= 3)
{
uint16_t time_code_endian;
size_t bytes_read;
reader->Read(&time_code_endian, sizeof(uint16_t), &bytes_read);
if (bytes_read != sizeof(uint16_t))
return 0;
binary.time_code = htons(time_code_endian);
size-=sizeof(uint16_t);
uint8_t flags;
reader->Read(&flags, 1, &bytes_read);
if (bytes_read != 1)
return 0;
binary.flags = flags;
size -= sizeof(uint8_t);
binary.data_size = (size_t)size;
#ifndef WA_VALIDATE
binary.data = malloc((size_t)size);
if (!binary.data)
return 0;
reader->Read(binary.data, (size_t)size, &bytes_read);
if (bytes_read != size)
{
free(binary.data);
return 0;
}
#else
printf(" track number = %I64u\n",binary.track_number);
printf(" timecode = %u\n",binary.time_code);
printf(" flags = %u\n",binary.flags);
printf(" data_size = %I64u\n",size);
// if we are validating the nmk file we don't need to
// actually read the data, just skip past it
//fseek(reader, size, SEEK_CUR);
#endif
return orig_size;
}
else
{
reader->Skip(size);
return orig_size;
}
return 0;
}
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