Module protocol_stack 

Protocol stack abstraction for network protocols

This module provides the infrastructure for protocol stacks (TCP/IP, UDP, etc.) to be integrated with Scarlet’s socket system.

Design

Protocol stacks bridge between high-level SocketObject and low-level network devices. They handle protocol-specific operations like:

• Packet encapsulation/decapsulation
• Connection state management
• Error handling and retransmission
• Flow control and congestion control

Architecture

Application
    ↓
SocketObject (ABI-specific, e.g., Linux TCP socket)
    ↓
ProtocolStack (TCP/IP, UDP, etc.)
    ↓
NetworkDevice (Ethernet, WiFi, etc.)

Layered Protocol Architecture

The new NetworkLayer trait provides a flexible, composable protocol stack:

Socket Layer
    ↓
Transport Layer (TCP=6, UDP=17)
    ↓ (register_protocol)
Network Layer (IP)
    ↓ (register_protocol)
Link Layer (Ethernet, InfiniBand)
    ↓
Physical Device

Each layer can:

• Register protocol handlers for upper layers
• Send packets to multiple lower layers
• Route based on protocol numbers

Structs

LayerContext

Context passed between network layers for routing decisions

NetworkLayerStats

Statistics for a network layer

ProtocolStackManager

Protocol stack manager

ProtocolStackStats

Protocol stack statistics

SocketConfig

Configuration for socket creation and layer binding

Traits

NetworkLayer

Network layer trait for composable protocol stacks

ProtocolStack

Protocol stack trait for network protocols

Functions

get_network_manager

Network layer manager