SAIF.Framework.DNS overview

Documentation context: Packaged Component (NuGet)

SAIF.Framework.DNS is a small, self-contained DNS client library that builds, sends, and parses DNS query/response messages over raw UDP sockets in accordance with RFC1035. It provides a static Resolver facade for issuing generic DNS lookups and a convenience MX-record lookup, with no dependencies on other SAIF framework components.

Purpose

• Provide a lightweight, dependency-free way for callers to perform DNS lookups (generic and MX-specific) directly over UDP, without relying on OS-level DNS resolution APIs.
• Encapsulate RFC1035 wire-format encoding and decoding (headers, questions, resource records, domain-name compression) behind a small object model (Request, Question, Response, ResourceRecord and its typed RDATA subtypes).
• Surface typed failure signals (NoResponseException, InvalidResponseException) so callers can distinguish transport failures from malformed responses.

Responsibilities

• Build and serialize DNS query messages from caller-supplied domain, type, and class values.
• Transmit query messages over UDP to a caller-specified DNS server on port 53, with retry and timeout handling.
• Parse raw UDP reply bytes into a structured Response, including header flags/counts and Question/Answer/NameServer/AdditionalRecord sections.
• Decode individual resource-record RDATA into typed records (ANameRecord, MXRecord, NSRecord, SoaRecord) based on the record's DnsType, skipping unrecognized types.
• Provide a convenience MX-lookup operation that filters and sorts MX answers by preference.

Key components

• Resolver: static entry-point facade exposing Lookup and MXLookup; owns UDP socket transfer and retry logic.
• Request / Question: caller-facing message builder and query descriptor.
• Response / ResourceRecord (and Answer, NameServer, AdditionalRecord): reply parser and shared resource-record wire-format parser.
• ANameRecord, MXRecord, NSRecord, SoaRecord: typed RDATA payloads.
• InvalidResponseException, NoResponseException: typed failure signals surfaced to callers.

Related documentation

• Index
• Architecture
• Dependencies
• Operations and processes
• Business rules
• Configuration
• API reference

Sources

• SAIF.Framework.DNS\SAIF.BOF.Framework.DNS.csproj
• SAIF.Framework.DNS\Resolver.cs
• SAIF.Framework.DNS\Request.cs
• SAIF.Framework.DNS\Question.cs
• SAIF.Framework.DNS\Response.cs
• SAIF.Framework.DNS\ResourceRecord.cs
• SAIF.Framework.DNS\RecordBase.cs