Struct TcpReassembler 

pub struct TcpReassembler { /* private fields */ }

TCP stream reassembly engine using a BTreeMap for out-of-order segment management.

Mirrors Wireshark’s reassemble.c logic: segments are keyed by absolute TCP sequence number. In-order segments are immediately appended to the contiguous reassembled buffer, while out-of-order segments are cached until gaps are filled.

Implementations

impl TcpReassembler

pub fn new() -> Self

Create a new uninitialized reassembler.

pub fn initialize(&mut self, initial_seq: u32)

Initialize with the first observed sequence number (ISN + 1 for data after SYN).

pub fn is_initialized(&self) -> bool

Whether this reassembler has been initialized.

pub fn reassembled_data(&self) -> &[u8]

Get the contiguous reassembled data if it’s in memory.

Returns None if the data has been spilled to disk. Use [read_reassembled] for guaranteed access regardless of storage location.

pub fn read_reassembled(&self) -> Result<Vec<u8>>

Read the reassembled data regardless of storage location.

Works for both in-memory and spilled-to-disk data.

pub fn drain_reassembled(&mut self) -> Result<Vec<u8>>

Drain and return the reassembled data, resetting the buffer.

pub fn buffered_bytes(&self) -> usize

Total bytes in the out-of-order buffer.

pub fn fragment_count(&self) -> usize

Number of out-of-order fragments.

pub fn in_memory_bytes(&self) -> usize

Total bytes currently held in memory (reassembled + OOO segments).

pub fn spill(&mut self, spill_dir: Option<&Path>) -> Result<usize>

Spill reassembled data to a temporary file on disk.

Returns the number of bytes freed from memory.

pub fn is_spilled(&self) -> bool

Whether the reassembled data has been spilled to disk.

pub fn process_segment( &mut self, seq: u32, payload: &[u8], config: &FlowConfig, ) -> Result<ReassemblyAction, FlowError>

Process an incoming TCP segment.

Handles in-order, out-of-order, overlapping, and duplicate segments according to the algorithm described in the architectural blueprint.

Trait Implementations

impl Debug for TcpReassembler

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TcpReassembler

fn default() -> Self

Returns the “default value” for a type.