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Reorganize reassembly data structures

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Started by factoring some details into a new DataBlockList class to at
least make it more clear where modifications occur.  More abstractions
likely to happen later as I experiment with alternate data structures
aimed at improving worse-case scenarios.
This commit is contained in:
Jon Siwek 2019-09-05 19:17:41 -07:00
parent 395c685da1
commit b19c8fad7a
8 changed files with 343 additions and 285 deletions
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67
src/Reassem.h
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@ -38,10 +38,48 @@ public:
Reassembler* reassembler; // Non-owning pointer back to parent.
};
// TODO: add comments
class DataBlockList {
public:
~DataBlockList()
{ Clear(); }
const DataBlock* Head() const
{ return head; }
const DataBlock* Tail() const
{ return tail; }
bool Empty() const
{ return head == nullptr; };
size_t NumBlocks() const
{ return total_blocks; };
void Size(uint64_t seq_cutoff, uint64_t* below, uint64_t* above) const;
void Clear();
DataBlock* Insert(uint64_t seq, uint64_t upper, const u_char* data,
Reassembler* reass, DataBlock* start = nullptr);
void Add(DataBlock* block, uint64_t limit);
uint64_t Trim(uint64_t seq, Reassembler* reass,
uint64_t max_old, DataBlockList* old_list);
private:
DataBlock* head = nullptr;
DataBlock* tail = nullptr;
size_t total_blocks = 0;
};
class Reassembler : public BroObj {
public:
Reassembler(uint64_t init_seq, ReassemblerType reassem_type = REASSEM_UNKNOWN);
~Reassembler() override;
~Reassembler() override {}
void NewBlock(double t, uint64_t seq, uint64_t len, const u_char* data);
@ -53,9 +91,17 @@ public:
void ClearBlocks();
void ClearOldBlocks();
int HasBlocks() const { return blocks != 0; }
int HasBlocks() const
{ return ! block_list.Empty(); }
uint64_t LastReassemSeq() const { return last_reassem_seq; }
uint64_t TrimSeq() const
{ return trim_seq; }
void SetTrimSeq(uint64_t seq)
{ if ( seq > trim_seq ) trim_seq = seq; }
uint64_t TotalSize() const; // number of bytes buffered up
void Describe(ODesc* d) const override;
@ -72,28 +118,23 @@ protected:
Reassembler() { }
friend class DataBlock;
friend class DataBlockList;
virtual void Undelivered(uint64_t up_to_seq);
virtual void BlockInserted(DataBlock* b) = 0;
virtual void BlockInserted(const DataBlock* b) = 0;
virtual void Overlap(const u_char* b1, const u_char* b2, uint64_t n) = 0;
DataBlock* AddAndCheck(DataBlock* b, uint64_t seq,
uint64_t upper, const u_char* data);
void CheckOverlap(DataBlock *head, DataBlock *tail,
void CheckOverlap(const DataBlockList& list,
uint64_t seq, uint64_t len, const u_char* data);
DataBlock* blocks;
DataBlock* last_block;
DataBlock* old_blocks;
DataBlock* last_old_block;
DataBlockList block_list;
DataBlockList old_block_list;
// TODO: maybe roll some of these stats into DataBlockList ?
uint64_t last_reassem_seq;
uint64_t trim_seq; // how far we've trimmed
uint32_t max_old_blocks;
uint32_t total_old_blocks;
uint64_t size_of_all_blocks;
ReassemblerType rtype;