How PacketScope Uses eBPF to Visualize and Secure TCP/IP Protocol Interactions

Introduction

PacketScope is an eBPF-based framework that provides a universal defense for the TCP/IP protocol stack. By dynamically observing the processing path of each packet, it draws a panoramic view of protocol interactions and, with large-model analysis, enables kernel-level packet visualization, security analysis, and zero-delay defense.

What Is Network Protocol Interaction?

Network protocol interaction refers to the collaborative process where different layers or types of protocols exchange messages, update states, and depend on each other to complete a network task. A simple web request involves DNS resolution, TCP three-way handshake, HTTP over TCP, and many other protocols such as ICMP, ARP, DHCP, TLS, etc., forming a cross-layer causal chain.

Why Visualizing Protocol Interaction Matters

Avoid “black-box” effect: Makes the hidden processing of each packet visible, revealing the complete causal chain between protocols.

Rapid fault and performance bottleneck identification: Pinpoints which protocol or stage causes anomalies, shortening troubleshooting time.

Security risk detection: Exposes abnormal cross-protocol paths that attackers may exploit.

Network optimization guidance: Provides data for routing, caching, and configuration decisions.

eBPF-Based Full-View Tracer

The Tracer inserts safe, efficient eBPF probes into the kernel without modifying the OS or stack code. It captures packets at the network interface, instruments key kernel functions (e.g., those containing “tcp”, “udp”, “icmp”, “sk_buff”), records thread IDs and timestamps, and binds packet data with function-call events.

Metrics quantified include layer traffic (packet count per layer), cross-layer interaction frequency, and cross-layer latency, providing a basis for fault diagnosis, performance tuning, and security analysis.

Installation and Usage

PacketScope 1.0 runs on Linux kernel 6.8. After installing the modules, users can start monitoring via the UI. The main view lists active sockets with their 5-tuple and state. Selecting a socket opens three tools:

Packet Analyzer: Shows tcpdump-like packet details (timestamp, interface, direction, length).

Function Call Chain Monitor: Displays the full kernel call path for each packet, highlighting performance hotspots and potential security risks.

Protocol Stack Monitor: Real-time metrics of packet flow, cross-layer latency, interaction frequency, and loss rate.

Future Outlook

Future work will extend PacketScope to application-level protocol tracing, distributed tracing across multiple hosts, and provide flexible APIs for custom observation points, further advancing endpoint security from external isolation to internal cognitive protection.