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Cleanup fragment reassembly

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This commit is contained in:
Keith Winstein
2011-08-12 15:05:58 -04:00
parent 221c3af908
commit a81f398200
3 changed files with 30 additions and 33 deletions
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networkinstruction.cpp
+21 -24
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@@ -25,7 +25,12 @@ string Instruction::tostring( void )
ret += network_order_string( new_num );
ret += network_order_string( ack_num );
ret += network_order_string( throwaway_num );
ret += network_order_string( fragment_num );
assert( !( fragment_num & 0x8000 ) );
uint16_t combined_fragment_num = ( final << 15 ) | fragment_num;
ret += network_order_string( combined_fragment_num );
assert( ret.size() == inst_header_len );
@@ -35,7 +40,7 @@ string Instruction::tostring( void )
}
Instruction::Instruction( string &x )
: old_num( -1 ), new_num( -1 ), ack_num( -1 ), throwaway_num( -1 ), fragment_num( -1 ), diff()
: old_num( -1 ), new_num( -1 ), ack_num( -1 ), throwaway_num( -1 ), fragment_num( -1 ), final( false ), diff()
{
assert( x.size() >= inst_header_len );
uint64_t *data = (uint64_t *)x.data();
@@ -45,6 +50,8 @@ Instruction::Instruction( string &x )
ack_num = be64toh( data[ 2 ] );
throwaway_num = be64toh( data[ 3 ] );
fragment_num = be16toh( data16[ 16 ] );
final = ( fragment_num & 0x8000 ) >> 15;
fragment_num &= 0x7FFF;
diff = string( x.begin() + inst_header_len, x.end() );
}
@@ -57,45 +64,35 @@ bool FragmentAssembly::same_template( Instruction &a, Instruction &b )
bool FragmentAssembly::add_fragment( Instruction &inst )
{
/* decode fragment num */
bool last_fragment = inst.fragment_num > 32767;
uint16_t real_fragment_num = inst.fragment_num;
if ( last_fragment ) {
real_fragment_num -= 32768;
}
/* see if this is a totally new packet */
if ( !same_template( inst, current_template ) ) {
fragments.clear();
current_template = inst;
fragments.resize( real_fragment_num + 1 );
fragments.at( real_fragment_num ) = inst;
fragments.resize( inst.fragment_num + 1 );
fragments.at( inst.fragment_num ) = inst;
fragments_arrived = 1;
fragments_total = -1;
} else { /* not a new packet */
/* see if we already have this fragment */
if ( (fragments.size() > real_fragment_num)
&& (fragments.at( real_fragment_num ).old_num != uint64_t(-1)) ) {
assert( fragments.at( real_fragment_num ) == inst );
if ( (fragments.size() > inst.fragment_num)
&& (fragments.at( inst.fragment_num ).old_num != uint64_t(-1)) ) {
assert( fragments.at( inst.fragment_num ) == inst );
} else {
if ( (int)fragments.size() < real_fragment_num + 1 ) {
fragments.resize( real_fragment_num + 1 );
if ( (int)fragments.size() < inst.fragment_num + 1 ) {
fragments.resize( inst.fragment_num + 1 );
}
fragments.at( real_fragment_num ) = inst;
fragments.at( inst.fragment_num ) = inst;
fragments_arrived++;
}
}
if ( last_fragment ) {
fragments_total = real_fragment_num + 1;
if ( inst.final ) {
fragments_total = inst.fragment_num + 1;
fragments.resize( fragments_total );
}
if ( fragments_arrived == fragments_total ) {
assert( (int)fragments.size() == fragments_total );
for ( unsigned int i = 0; i < fragments.size(); i++ ) {
assert( fragments.at( i ).old_num != uint64_t(-1) );
}
if ( fragments_total != -1 ) {
assert( fragments_arrived <= fragments_total );
}
/* see if we're done */