Backhaul

Welcome to the Backhaul project! This project provides a high-performance reverse tunneling solution optimized for handling massive concurrent connections through NAT and firewalls. This README will guide you through setting up and configuring both server and client components, including details on different transport protocols.

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Table of Contents

1. Introduction
2. Features
3. Installation
4. Usage
   • Configuration Options
   • Detailed Configuration
     • TCP Configuration
     • TCP Multiplexing Configuration
     • UDP Configuration
     • WebSocket Configuration
     • Secure WebSocket Configuration
     • WS Multiplexing Configuration
     • WSS Multiplexing Configuration
5. Generating a Self-Signed TLS Certificate with OpenSSL
6. Running backhaul as a service
7. FAQ
8. Benchmark
9. License
10. Donation

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Introduction

This project offers a robust reverse tunneling solution to overcome NAT and firewall restrictions, supporting various transport protocols. It’s engineered for high efficiency and concurrency.

Features

• High Performance: Optimized for handling massive concurrent connections efficiently.
• Protocol Flexibility: Supports TCP, WebSocket (WS), and Secure WebSocket (WSS) transports.
• UDP over TCP: Implements UDP traffic encapsulation and forwarding over a TCP connection for reliable delivery with built-in congestion control.
• Multiplexing: Enables multiple connections over a single transport with SMUX.
• NAT & Firewall Bypass: Overcomes restrictions with reverse tunneling.
• Traffic Sniffing: Optional network traffic monitoring with logging support.
• Configurable Keepalive: Adjustable keep-alive and heartbeat intervals for stable connections.
• TLS Encryption: Secure connections via WSS with support for custom TLS certificates.
• Web Interface: Real-time monitoring through a lightweight web interface.
• Hot Reload Configuration: Supports dynamic configuration reloading without server restarts.

Installation

1. Download the latest release from the GitHub releases page.

2. Extract the archive (adjust the filename if needed):

   tar -xzf backhaul_linux_amd64.tar.gz

3. Run the executable:

   ./backhaul

4. You can also build from source if preferred:

   git clone https://github.com/musixal/backhaul.git
   cd backhaul
   go build
   ./backhaul

Usage

The main executable for this project is backhaul. It requires a TOML configuration file for both the server and client components.

Configuration Options

To start using the solution, you'll need to configure both server and client components. Here’s how to set up basic configurations:

• Server Configuration

  Create a configuration file named config.toml:

  [server]# Local, IRAN
  bind_addr = "0.0.0.0:3080"    # Address and port for the server to listen on (mandatory).
  transport = "tcp"             # Protocol to use ("tcp", "tcpmux", "ws", "wss", "wsmux", "wssmux". mandatory).
  accept_udp = false             # Enable transferring UDP connections over TCP transport. (optional, default: false)
  token = "your_token"          # Authentication token for secure communication (optional).
  keepalive_period = 75         # Interval in seconds to send keep-alive packets.(optional, default: 75s)
  nodelay = false               # Enable TCP_NODELAY (optional, default: false).
  channel_size = 2048           # Tunnel and Local channel size. Excess connections are discarded. (optional, default: 2048).
  heartbeat = 40                # In seconds. Ping interval for tunnel stability. Min: 1s. (Optional, default: 40s)
  mux_con = 8                   # Mux concurrency. Number of connections that can be multiplexed into a single stream (optional, default: 8).
  mux_version = 1               # SMUX protocol version (1 or 2). Version 2 may have extra features. (optional)
  mux_framesize = 32768         # 32 KB. The maximum size of a frame that can be sent over a connection. (optional)
  mux_recievebuffer = 4194304   # 4 MB. The maximum buffer size for incoming data per connection. (optional)
  mux_streambuffer = 65536      # 256 KB. The maximum buffer size per individual stream within a connection. (optional)
  sniffer = false               # Enable or disable network sniffing for monitoring data. (optional, default false)
  web_port = 2060               # Port number for the web interface or monitoring interface. (optional, set to 0 to disable).
  sniffer_log ="/root/log.json" # Filename used to store network traffic and usage data logs. (optional, default backhaul.json)
  tls_cert = "/root/server.crt" # Path to the TLS certificate file for wss/wssmux. (mandatory).
  tls_key = "/root/server.key"  # Path to the TLS private key file for wss/wssmux. (mandatory).
  log_level = "info"            # Log level ("panic", "fatal", "error", "warn", "info", "debug", "trace", optional, default: "info").
  
  ports = [
  "443-600",                  # Listen on all ports in the range 443 to 600
  "443-600:5201",             # Listen on all ports in the range 443 to 600 and forward traffic to 5201
  "443-600=1.1.1.1:5201",     # Listen on all ports in the range 443 to 600 and forward traffic to 1.1.1.1:5201
  "443",                      # Listen on local port 443 and forward to remote port 443 (default forwarding).
  "4000=5000",                # Listen on local port 4000 (bind to all local IPs) and forward to remote port 5000.
  "127.0.0.2:443=5201",       # Bind to specific local IP (127.0.0.2), listen on port 443, and forward to remote port 5201.
  "443=1.1.1.1:5201",         # Listen on local port 443 and forward to a specific remote IP (1.1.1.1) on port 5201.
  "127.0.0.2:443=1.1.1.1:5201",  # Bind to specific local IP (127.0.0.2), listen on port 443, and forward to remote IP (1.1.1.1) on port 5201.
  ]
  

  To start the server:

  ./backhaul -c config.toml

• Client Configuration

  Create a configuration file named config.toml for the client:

  [client]  # Behind NAT, firewall-blocked
  remote_addr = "0.0.0.0:3080"  # Server address and port (mandatory).
  edge_ip = "188.114.96.0"      # Edge IP used for CDN connection, specifically for WebSocket-based transports.(Optional, default none)
  transport = "tcp"             # Protocol to use ("tcp", "tcpmux", "ws", "wss", "wsmux", "wssmux". mandatory).
  token = "your_token"          # Authentication token for secure communication (optional).
  connection_pool = 8           # Number of pre-established connections.(optional, default: 8).
  aggressive_pool = false       # Enables aggressive connection pool management.(optional, default: false).
  keepalive_period = 75         # Interval in seconds to send keep-alive packets. (optional, default: 75s)
  nodelay = false               # Use TCP_NODELAY (optional, default: false).
  retry_interval = 3            # Retry interval in seconds (optional, default: 3s).
  dial_timeout = 10             # Sets the max wait time for establishing a network connection. (optional, default: 10s)
  mux_version = 1               # SMUX protocol version (1 or 2). Version 2 may have extra features. (optional)
  mux_framesize = 32768         # 32 KB. The maximum size of a frame that can be sent over a connection. (optional)
  mux_recievebuffer = 4194304   # 4 MB. The maximum buffer size for incoming data per connection. (optional)
  mux_streambuffer = 65536      # 256 KB. The maximum buffer size per individual stream within a connection. (optional)
  sniffer = false               # Enable or disable network sniffing for monitoring data. (optional, default false)
  web_port = 2060               # Port number for the web interface or monitoring interface. (optional, set to 0 to disable).
  sniffer_log ="/root/log.json" # Filename used to store network traffic and usage data logs. (optional, default backhaul.json)
  log_level = "info"            # Log level ("panic", "fatal", "error", "warn", "info", "debug", "trace", optional, default: "info").

  To start the client:

  ./backhaul -c config.toml

Detailed Configuration

TCP Configuration

• Server:

  [server]
  bind_addr = "0.0.0.0:3080"
  transport = "tcp"
  accept_udp = false 
  token = "your_token"
  keepalive_period = 75  
  nodelay = true 
  heartbeat = 40 
  channel_size = 2048
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  ports = []

• Client:

  [client]
  remote_addr = "0.0.0.0:3080"
  transport = "tcp"
  token = "your_token" 
  connection_pool = 8
  aggressive_pool = false
  keepalive_period = 75
  dial_timeout = 10
  nodelay = true 
  retry_interval = 3
  sniffer = false
  web_port = 2060 
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  

• Details:

  remote_addr: The IPv4, IPv6, or domain address of the server to which the client connects.

  token: An authentication token used to securely validate and authenticate the connection between the client and server within the tunnel.

  channel_size: The queue size for forwarding packets from server to the client. If the limit is exceeded, packets will be dropped.

  connection_pool: Set the number of pre-established connections for better latency.

  nodelay: Refers to a TCP socket option (TCP_NODELAY) that improve the latency but decrease the bandwidth

TCP Multiplexing Configuration

• Server:

  [server]
  bind_addr = "0.0.0.0:3080"
  transport = "tcpmux"
  token = "your_token" 
  keepalive_period = 75
  nodelay = true 
  heartbeat = 40 
  channel_size = 2048
  mux_con = 8
  mux_version = 1
  mux_framesize = 32768 
  mux_recievebuffer = 4194304
  mux_streambuffer = 65536 
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  ports = []

• Client:

  [client]
  remote_addr = "0.0.0.0:3080"
  transport = "tcpmux"
  token = "your_token" 
  connection_pool = 8
  aggressive_pool = false
  keepalive_period = 75
  dial_timeout = 10
  retry_interval = 3
  nodelay = true 
  mux_version = 1
  mux_framesize = 32768 
  mux_recievebuffer = 4194304
  mux_streambuffer = 65536 
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"

• Details:

  mux_session: Number of multiplexed sessions. Increase this if you need to handle more simultaneous sessions over a single connection.

  • Refer to TCP configuration for more information.

UDP Configuration

• Server:

  [server]
  bind_addr = "0.0.0.0:3080"
  transport = "udp"
  token = "your_token"
  heartbeat = 20 
  channel_size = 2048
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  ports = []

• Client:

  [client]
  remote_addr = "0.0.0.0:3080"
  transport = "udp"
  token = "your_token" 
  connection_pool = 8
  aggressive_pool = false
  retry_interval = 3
  sniffer = false
  web_port = 2060 
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  

WebSocket Configuration

• Server:

  [server]
  bind_addr = "0.0.0.0:8080"
  transport = "ws"
  token = "your_token" 
  channel_size = 2048
  keepalive_period = 75 
  heartbeat = 40
  nodelay = true 
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  ports = []

• Client:

  [client]
  remote_addr = "0.0.0.0:8080"
  edge_ip = "" 
  transport = "ws"
  token = "your_token" 
  connection_pool = 8
  aggressive_pool = false
  keepalive_period = 75 
  dial_timeout = 10
  retry_interval = 3
  nodelay = true 
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"

• Details:

  • Refer to TCP configuration for more information.

Secure WebSocket Configuration

• Server:

  [server]
  bind_addr = "0.0.0.0:8443"
  transport = "wss"
  token = "your_token" 
  channel_size = 2048
  keepalive_period = 75 
  nodelay = true 
  tls_cert = "/root/server.crt"      
  tls_key = "/root/server.key"
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  ports = []

• Client:

  [client]
  remote_addr = "0.0.0.0:8443"
  edge_ip = "" 
  transport = "wss"
  token = "your_token" 
  connection_pool = 8
  aggressive_pool = false
  keepalive_period = 75
  dial_timeout = 10
  retry_interval = 3  
  nodelay = true 
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"

• Details:

  • Refer to the next section for instructions on generating tls_cert and tls_key.

WS Multiplexing Configuration

• Server:

  [server]
  bind_addr = "0.0.0.0:3080"
  transport = "wsmux"
  token = "your_token" 
  keepalive_period = 75
  nodelay = true 
  heartbeat = 40 
  channel_size = 2048
  mux_con = 8
  mux_version = 1
  mux_framesize = 32768 
  mux_recievebuffer = 4194304
  mux_streambuffer = 65536 
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  ports = []

• Client:

  [client]
  remote_addr = "0.0.0.0:3080"
  edge_ip = "" 
  transport = "wsmux"
  token = "your_token" 
  connection_pool = 8
  aggressive_pool = false
  keepalive_period = 75
  dial_timeout = 10
  nodelay = true
  retry_interval = 3
  mux_version = 1
  mux_framesize = 32768 
  mux_recievebuffer = 4194304
  mux_streambuffer = 65536 
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"

WSS Multiplexing Configuration

• Server:

  [server]
  bind_addr = "0.0.0.0:443"
  transport = "wssmux"
  token = "your_token" 
  keepalive_period = 75
  nodelay = true 
  heartbeat = 40 
  channel_size = 2048
  mux_con = 8
  mux_version = 1
  mux_framesize = 32768 
  mux_recievebuffer = 4194304
  mux_streambuffer = 65536 
  tls_cert = "/root/server.crt"      
  tls_key = "/root/server.key"
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"
  ports = []

• Client:

  [client]
  remote_addr = "0.0.0.0:443"
  edge_ip = "" 
  transport = "wssmux"
  token = "your_token" 
  keepalive_period = 75
  dial_timeout = 10
  nodelay = true
  retry_interval = 3
  connection_pool = 8
  aggressive_pool = false
  mux_version = 1
  mux_framesize = 32768 
  mux_recievebuffer = 4194304
  mux_streambuffer = 65536  
  sniffer = false 
  web_port = 2060
  sniffer_log = "/root/backhaul.json"
  log_level = "info"

Generating a Self-Signed TLS Certificate with OpenSSL

To generate a TLS certificate and key, you can use tools like OpenSSL. Here’s a step-by-step guide on how to create a self-signed certificate and key using OpenSSL:

Step 1: Install OpenSSL

If you don't already have OpenSSL installed, you can install it using your system's package manager.

• On Ubuntu/Debian:

  sudo apt-get install openssl

Step 2: Generate a Private Key

To generate a 2048-bit RSA private key, run the following command:

openssl genpkey -algorithm RSA -out server.key -pkeyopt rsa_keygen_bits:2048

This will create a file named server.key, which is your private key.

Step 3: Generate a Certificate Signing Request (CSR)

Create a Certificate Signing Request (CSR) using the private key. This CSR is used to generate the SSL certificate:

openssl req -new -key server.key -out server.csr

You will be prompted to enter information for the CSR. For the common name (CN), use the domain name or IP address where your server will be hosted. Example:

Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:California
Locality Name (eg, city) []:San Francisco
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Your Company Name
Organizational Unit Name (eg, section) []:
Common Name (e.g. server FQDN or YOUR name) []:example.com
Email Address []:

Step 4: Generate a Self-Signed Certificate

Use the CSR and private key to generate a self-signed certificate. Specify the validity period (in days):

openssl x509 -req -in server.csr -signkey server.key -out server.crt -days 365

This will generate a certificate named server.crt, valid for 365 days.

Recap of the Files Generated:

• server.key: Your private key.
• server.csr: The certificate signing request (used to generate the certificate).
• server.crt: Your self-signed TLS certificate.

Running backhaul as a service

To create a service file for your backhaul project that ensures the service restarts automatically, you can use the following template for a systemd service file. Assuming your project runs a reverse tunnel and the main executable file is located in a certain path, here's a basic example:

1. Create the service file /etc/systemd/system/backhaul.service:

[Unit]
Description=Backhaul Reverse Tunnel Service
After=network.target

[Service]
Type=simple
ExecStart=/root/backhaul -c /root/config.toml
Restart=always
RestartSec=3
LimitNOFILE=1048576

[Install]
WantedBy=multi-user.target

2. After creating the service file, enable and start the service:

sudo systemctl daemon-reload
sudo systemctl enable backhaul.service
sudo systemctl start backhaul.service

3. To verify if the service is running:

sudo systemctl status backhaul.service

4. View the most recent log entries for the backhaul.service unit:

journalctl -u backhaul.service -e -f

FAQ

Q: How do I decide which transport protocol to use?

• tcp: Use if you need straightforward TCP connections.
• tcpmux: Use if you need to handle multiple sessions over a single connection.
• ws: Use if you need to traverse HTTP-based firewalls or proxies.
• wss: Use this for secure WebSocket connections that need to traverse HTTP-based firewalls or proxies. It encrypts data for added security, similar to WS but with encryption.

Benchmark

For in-depth information, please visit the dedicated Benchmark page.

License

This project is licensed under the AGPL-3.0 license. See the LICENSE file for details.

Donation

Donate TRX (TRC-20) to support our project:

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Thanks for your support!

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