UDP-Smasher

Elite High-Performance UDP Network Stress Testing Tool

📌 Overview

UDP-Smasher is a high-performance UDP packet generator designed for authorized network stress testing, protocol validation, and research environments.
Written in Go using raw sockets, it achieves extremely high packet throughput by minimizing kernel overhead and leveraging efficient memory handling techniques.

License: MIT — see the LICENSE file for full terms.

⚠️ This tool is strictly for legal and authorized use only.

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⚡ Performance Highlights

• Throughput: ~350,000 – 400,000 packets per second (sustained)
• Packet Size: 28 bytes (minimum UDP + IPv4 headers)
• Concurrency Model: CPU cores × 8 workers
• Source IP Diversity: /16 subnet spoofing (65,536 unique IPs)
• Latency: Sub-microsecond batch dispatch

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🏗️ Architecture Overview

┌─────────────────────────────────────────────┐
│ Control Plane                               │
│ • Interactive CLI                           │
│ • Automatic interface detection             │
│ • Real-time PPS monitoring                  │
└───────────────────┬─────────────────────────┘
                    │
┌───────────────────▼─────────────────────────┐
│ Worker Pool (CPU × 8)                        │
│ ┌─────────┐ ┌─────────┐ ┌─────────┐         │
│ │ Worker  │ │ Worker  │ │ Worker  │  ...    │
│ └────┬────┘ └────┬────┘ └────┬────┘         │
└───────┼───────────┼──────────────┼─────────┘
        │           │              │
┌───────▼───────────▼──────────────▼─────────┐
│ Packet Factory                              │
│ • Zero-allocation packet crafting           │
│ • Incremental checksum computation          │
│ • Randomized source IP & port generation    │
└───────┬────────────────────────────────────┘
        │
┌───────▼────────────────────────────────────┐
│ Raw Socket Layer                            │
│ • IP_HDRINCL enabled                        │
│ • Interface-bound sockets                  │
│ • Large socket buffers (128MB)              │
└───────────────────────────────────────────┘

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🚀 Installation

Requirements

• Linux (raw socket support required)
• Go 1.20+
• Root or cap_net_raw capability

Build

```bash
git clone https://github.com/mufaizz/UDP-Smasher.git
cd UDP-Smasher
go build -ldflags "-s -w" -o attack main.go

Set Capabilities (Recommended)

sudo setcap cap_net_raw=ep attack

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📖 Usage

sudo ./attack

Interactive Prompt

Target IP:   192.168.1.100
Target Port: 8080

The tool will immediately begin packet transmission and display live PPS statistics.

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🔧 Technical Implementation

Packet Structure

[ IPv4 Header : 20 bytes ]
[ UDP Header  :  8 bytes ]

Key Fields

• TTL: 64

• Protocol: UDP (17)

• IP Identification: Randomized

• Source IP: Randomized from /16 range

• Source Port: Random (1024–65535)

• Checksums: Incrementally computed

⚙️ Optimization Techniques

• Batch Processing: 1024 packets per syscall loop

• Memory Pooling: Pre-allocated reusable buffers

• Lock-Free Counters: Atomic operations for stats

• CPU Affinity: Workers pinned to CPU cores

• Kernel Bypass: Raw sockets with full header control

📊 Performance Tuning

Recommended Kernel Parameters

sudo sysctl -w net.core.rmem_max=134217728
sudo sysctl -w net.core.wmem_max=134217728
sudo sysctl -w net.ipv4.udp_mem="134217728 134217728 134217728"

Optional NIC Offload Disable

sudo ethtool -K eth0 tx off rx off gso off gro off

🧪 Testing & Validation

• Baseline: iperf -s -u

• Packet Capture: tcpdump -i eth0 udp

• Traffic Monitor: iftop -i eth0

• Socket Stats: ss -unp

📈 Runtime Profile

CPU Usage:        90–95% kernel, 5–10% user
Memory Usage:     < 50 MB RSS
Threads:          CPU cores + 2
File Descriptors: One raw socket per worker
Context Switches: Minimal (LockOSThread)

🐛 Known Limitations

• Reduced throughput in virtualized environments

• Linux-only (raw socket dependency)

• Requires elevated privileges

• Bypasses netfilter / conntrack

🛡️ Legal & Ethical Use

✔ Allowed

• Authorized penetration testing

• Network equipment benchmarking

• Academic & protocol research

• CTFs and lab environments (with permission)

❌ Prohibited

• Unauthorized testing

• Malicious activity

• Violation of local or international laws

• Users are solely responsible for legal compliance.

🤝 Contributing

1.Fork the repository

2.Create a feature branch

3.Commit your changes

4.Push to your fork

5.Open a Pull Request

License

This repository is licensed under the MIT License — see the LICENSE file for details.

##Contact

E-mail: mufaizmalik9622@gmail.com

Instagram: https://www.instagram.com/muffizz

🙏 Acknowledgments

• **Linux kernel networking stack

• **Go syscall and net packages

• **Open-source security research community

Disclaimer:

This project demonstrates low-level networking capabilities for research and testing purposes. Use responsibly and only on networks you own or are explicitly authorized to test.