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Remove linked list from reassembly data structures

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Everything, including iteration is now done via an std::map
This commit is contained in:
Jon Siwek 2019-09-13 13:57:32 -07:00
parent 9b13825e16
commit e1e779e90b
8 changed files with 248 additions and 254 deletions
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42
src/Frag.cc
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@ -185,24 +185,32 @@ void FragReassembler::Overlap(const u_char* b1, const u_char* b2, uint64_t n)
Weird("fragment_overlap");
}
void FragReassembler::BlockInserted(const DataBlock* /* start_block */)
void FragReassembler::BlockInserted(DataBlockMap::const_iterator /* it */)
{
const DataBlock* b = block_list.Head();
// TODO: review all iteration here to see if it can be done better
auto it = block_list.Begin();
if ( b->seq > 0 || ! frag_size )
if ( it->second->seq > 0 || ! frag_size )
// For sure don't have it all yet.
return;
auto next = std::next(it);
// We might have it all - look for contiguous all the way.
for ( ; b->next; b = b->next )
if ( b->upper != b->next->seq )
while ( next != block_list.End() )
{
if ( it->second->upper != next->second->seq )
break;
if ( b->next )
++it;
++next;
}
auto last = std::prev(block_list.End())->second;
if ( next != block_list.End() )
{
// We have a hole.
if ( b->upper >= frag_size )
if ( it->second->upper >= frag_size )
{
// We're stuck. The point where we stopped is
// contiguous up through the expected end of
@ -215,19 +223,19 @@ void FragReassembler::BlockInserted(const DataBlock* /* start_block */)
// We decide to analyze the contiguous portion now.
// Extend the fragment up through the end of what
// we have.
frag_size = b->upper;
frag_size = it->second->upper;
}
else
return;
}
else if ( block_list.Tail()->upper > frag_size )
else if ( last->upper > frag_size )
{
Weird("fragment_size_inconsistency");
frag_size = block_list.Tail()->upper;
frag_size = last->upper;
}
else if ( block_list.Tail()->upper < frag_size )
else if ( last->upper < frag_size )
// Missing the tail.
return;
@ -248,12 +256,15 @@ void FragReassembler::BlockInserted(const DataBlock* /* start_block */)
pkt += proto_hdr_len;
for ( b = block_list.Head(); b; b = b->next )
for ( it = block_list.Begin(); it != block_list.End(); ++it )
{
auto b = it->second;
DataBlock* prev = it == block_list.Begin() ? nullptr : std::prev(it)->second;
// If we're above a hole, stop. This can happen because
// the logic above regarding a hole that's above the
// expected fragment size.
if ( b->prev && b->prev->upper < b->seq )
if ( prev && prev->upper < b->seq )
break;
if ( b->upper > n )
@ -265,8 +276,7 @@ void FragReassembler::BlockInserted(const DataBlock* /* start_block */)
return;
}
memcpy((void*) &pkt[b->seq], (const void*) b->block,
b->upper - b->seq);
memcpy(&pkt[b->seq], b->block, b->upper - b->seq);
}
delete reassembled_pkt;