Architecture Overview

nx9-dns-server is designed with a modular architecture that emphasizes performance, security, and maintainability. This page provides an overview of the technical architecture and design principles.

Core Components

1. DNS Server Engine

The core DNS server engine handles DNS query processing and response generation. It: - Listens for DNS queries on both UDP and TCP ports (default: 53) - Parses and validates incoming DNS packets - Retrieves relevant DNS records from the database - Constructs RFC-compliant DNS responses - Handles DNSSEC signing when enabled - Manages query caching for performance optimization

2. Storage Layer

The storage layer manages persistence of DNS records: - Uses SQLite for reliable, file-based storage - Provides efficient indexing for fast record lookups - Supports transaction-based updates for data integrity - Handles schema migrations for version upgrades

3. Web UI (Coming Soon)

The administrative web interface will provide: - User-friendly dashboard for DNS management - Record creation and editing capabilities - DNSSEC key management - User account administration - Operational statistics and logs

4. API Service (Coming Soon)

The RESTful API service will enable: - Programmatic DNS record management - Integration with external systems - Automation of DNS operations - Batch record operations

5. User Management (Coming Soon)

The user management system will support: - Multi-user access with role-based permissions - Authentication and authorization - Audit logging of administrative actions - API token management

Technology Stack

nx9-dns-server is built with the following technologies:

Language and Runtime

  • Rust: Core implementation language (2021 edition)
  • Tokio: Asynchronous runtime for high-performance I/O

Database

  • SQLite: Embedded database for DNS record storage
  • rusqlite: Rust SQLite binding for database operations

Networking

  • Tokio: For async UDP/TCP socket handling
  • DNS Protocol: RFC-compliant implementation

Web (Coming Soon)

  • Rocket or Axum: Web framework for UI and API
  • Frontend: (TBD) - Modern web framework

Security

  • DNSSEC: Built-in support for secure DNS
  • JWT: Token-based authentication (planned)
  • RBAC: Role-based access control (planned)

Deployment

  • Docker: Containerized deployment option
  • Alpine Linux: Minimal base image for containers
  • Systemd: Service management for traditional deployment

Data Flow

  1. Query Processing: Client → DNS Query → nx9-dns-server → Parse Query → Database Lookup → Generate Response → Client

  2. Record Management: Admin → Web UI/API → Authentication → Validation → Database Update → Log Change

  3. DNSSEC Signing: Record → Load DNSSEC Key → Generate Signature → Add RRSIG → Response

Performance Considerations

nx9-dns-server is designed for high performance:

  • Asynchronous I/O: Non-blocking operations for handling thousands of concurrent queries
  • Connection Pooling: Efficient database connection management
  • Query Caching: In-memory cache for frequently accessed records
  • Minimal Allocations: Careful memory management to reduce GC pressure
  • Optimized Packet Parsing: Efficient binary protocol handling

Security Architecture

Security is a primary concern in the design:

  • Input Validation: Strict validation of all incoming queries
  • DNSSEC: Support for cryptographically signed DNS responses
  • Least Privilege: Running with minimal required permissions
  • Memory Safety: Rust's safety guarantees prevent common vulnerabilities
  • Audit Logging: Comprehensive logging of security-relevant events

Future Architecture Expansions

Planned architectural enhancements include:

  • Clustering: Distributed deployment for high availability
  • Metrics: Prometheus integration for operational monitoring
  • Zone Transfers: AXFR/IXFR support for secondary servers
  • Dynamic Updates: RFC 2136 support for programmatic updates
  • DoH/DoT: Support for encrypted DNS protocols