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dns_parse : DNS Message Build and Parse

A lightweight DNS message builder and parser library, used by idoq (DoQ) and idot (DoT).

Features

• Build DNS query messages with EDNS support
• Parse DNS response messages
• Support A, AAAA, MX, TXT, NS, CNAME, PTR, SRV record types
• DNS name compression (pointer) handling
• Zero-copy parsing with bytes crate

Installation

[dependencies]
dns_parse = "0.1"

Usage

Build DNS Query

use dns_parse::build;

// Build query with message ID, domain, and query type
let msg = build(0x1234, "example.com", 1); // A record
let msg = build(0, "example.com", 28);     // AAAA record (ID=0 for DoQ)

Parse DNS Response

use dns_parse::parse;
use bytes::Bytes;

let response: Bytes = /* DNS response data */;
match parse(response) {
  Ok(answers) => {
    for a in answers {
      println!("{} {} TTL={}", a.name, a.val, a.ttl);
    }
  }
  Err(e) => eprintln!("Parse error: {e}"),
}

API Reference

Functions

build

Build a DNS query message.

pub fn build(id: u16, domain: &str, qtype: u16) -> Bytes

• id: Message ID (0 for DoQ per RFC 9250, random for DoT)
• domain: Query domain name
• qtype: Query type (1=A, 28=AAAA, 15=MX, etc.)

Returns DNS query message with EDNS OPT record (4096 byte UDP payload).

parse

Parse a DNS response message.

pub fn parse(data: Bytes) -> Result<Vec<Answer>>

Returns parsed answer records. Empty vector for NXDOMAIN or error responses.

Types

Answer (from idns)

pub struct Answer {
  pub name: String,   // Record name
  pub val: String,    // Record value (formatted)
  pub type_id: u16,   // Record type
  pub ttl: u32,       // Time to live
}

Error Types

• ResponseTooShort - Response less than 12 bytes
• IncompleteData - Truncated record data
• NameOutOfBounds - Name extends beyond message
• PointerOutOfBounds - Invalid compression pointer

Record Value Formats

Tech Stack

About

This project is an open-source component of js0.site ⋅ Refactoring the Internet Plan.

We are redefining the development paradigm of the Internet in a componentized way. Welcome to follow us:

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dns_parse : DNS 消息构建与解析

轻量级 DNS 消息构建和解析库，供 idoq (DoQ) 和 idot (DoT) 使用。

特性

• 构建带 EDNS 的 DNS 查询消息
• 解析 DNS 响应消息
• 支持 A、AAAA、MX、TXT、NS、CNAME、PTR、SRV 记录
• DNS 名称压缩（指针）处理
• 基于 bytes 的零拷贝解析

安装

[dependencies]
dns_parse = "0.1"

使用

构建 DNS 查询

use dns_parse::build;

// 构建查询：消息 ID、域名、查询类型
let msg = build(0x1234, "example.com", 1); // A 记录
let msg = build(0, "example.com", 28);     // AAAA 记录 (DoQ 要求 ID=0)

解析 DNS 响应

use dns_parse::parse;
use bytes::Bytes;

let response: Bytes = /* DNS 响应数据 */;
match parse(response) {
  Ok(answers) => {
    for a in answers {
      println!("{} {} TTL={}", a.name, a.val, a.ttl);
    }
  }
  Err(e) => eprintln!("解析错误: {e}"),
}

API 参考

函数

build

构建 DNS 查询消息。

pub fn build(id: u16, domain: &str, qtype: u16) -> Bytes

• id: 消息 ID（DoQ 按 RFC 9250 要求为 0，DoT 可随机）
• domain: 查询域名
• qtype: 查询类型（1=A, 28=AAAA, 15=MX 等）

返回带 EDNS OPT 记录（4096 字节 UDP 负载）的 DNS 查询消息。

parse

解析 DNS 响应消息。

pub fn parse(data: Bytes) -> Result<Vec<Answer>>

返回解析后的应答记录。NXDOMAIN 或错误响应返回空向量。

类型

Answer（来自 idns）

pub struct Answer {
  pub name: String,   // 记录名称
  pub val: String,    // 记录值（格式化后）
  pub type_id: u16,   // 记录类型
  pub ttl: u32,       // 生存时间
}

错误类型

• ResponseTooShort - 响应小于 12 字节
• IncompleteData - 记录数据截断
• NameOutOfBounds - 名称超出消息边界
• PointerOutOfBounds - 无效压缩指针

记录值格式

技术栈

关于

本项目为 js0.site ⋅ 重构互联网计划 的开源组件。

我们正在以组件化的方式重新定义互联网的开发范式，欢迎关注：

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