DenozordecandClaude Sonnet 5.5
f3531c64f9
Install ReUI (MCP, skill, @reui registry, Tailwind v4, shadcn base-nova) and move the shared UI onto it: Button, Tag, Check, Input/Textarea, Segmented, Alert, Panel, Dialog, Tooltip, Menu and Select (Popover), Toast (sonner), the Table frame (DataGrid), the Dashboard KPI strip, the shnt Ops palette, Geist and the type scale. Design only: behaviour, texts and roles are unchanged. Tests that asserted the old DOM were updated; the tests now format numbers in English wherever they run. docs/reui-migration-plan.md records the plan and its decisions. Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
98 lines
3.1 KiB
TypeScript
98 lines
3.1 KiB
TypeScript
/*
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Just enough of the DNS wire format (RFC 1035) to answer one question.
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The DNS server asks this endpoint over DNS-over-HTTPS (RFC 8484), so what comes
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in is a binary DNS message and what goes out must be one too. Technitium checks
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that the answer carries the query's ID and question (`ValidateResponse` in
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TechnitiumLibrary's `HttpsClientConnection.cs`), and nothing else: it accepts an
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answer without an OPT record even when the query had one.
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Web APIs only (`Uint8Array`, `DataView`): `Buffer` does not exist in a Cloudflare
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Function.
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*/
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export const TYPE_TXT = 16
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export interface DnsQuery {
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id: number
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rd: boolean
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/** Lower-cased, without the trailing dot. */
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name: string
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type: number
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/** The question section as it came: QNAME, QTYPE and QCLASS. */
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question: Uint8Array<ArrayBuffer>
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}
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export function parseQuery(message: Uint8Array): DnsQuery | null {
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if (message.length < 12) return null
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const view = new DataView(message.buffer, message.byteOffset, message.byteLength)
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if (view.getUint16(4) !== 1) return null
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const labels: string[] = []
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let at = 12
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for (;;) {
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if (at >= message.length) return null
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const length = message[at]
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if (length === 0) break
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// A query has no earlier name to point to, so compression is malformed here.
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if (length > 63) return null
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if (at + 1 + length > message.length) return null
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labels.push(String.fromCharCode(...message.subarray(at + 1, at + 1 + length)))
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at += 1 + length
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}
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at += 1
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// RFC 1035: a name is at most 255 bytes on the wire, its root included.
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if (at - 12 > 255) return null
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if (at + 4 > message.length) return null
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return {
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id: view.getUint16(0),
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rd: (view.getUint16(2) & 0x0100) !== 0,
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name: labels.join('.').toLowerCase(),
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type: view.getUint16(at),
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question: message.slice(12, at + 4),
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}
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}
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/* rcode: 0 NOERROR, 1 FORMERR, 2 SERVFAIL, 3 NXDOMAIN. */
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export function buildResponse(
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query: DnsQuery,
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rcode: 0 | 1 | 2 | 3,
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txt?: { text: string; ttl: number },
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): Uint8Array<ArrayBuffer> {
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const strings: Uint8Array[] = []
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if (txt) {
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const bytes = new TextEncoder().encode(txt.text)
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for (let i = 0; i < bytes.length; i += 255) strings.push(bytes.subarray(i, i + 255))
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if (strings.length === 0) strings.push(new Uint8Array(0))
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}
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const rdlength = strings.reduce((n, s) => n + 1 + s.length, 0)
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const answer = txt ? 12 + rdlength : 0
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const out = new Uint8Array(12 + query.question.length + answer)
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const view = new DataView(out.buffer)
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view.setUint16(0, query.id)
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// QR, AA and RA set; RD copied from the query.
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view.setUint16(2, 0x8000 | 0x0400 | (query.rd ? 0x0100 : 0) | 0x0080 | rcode)
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view.setUint16(4, 1)
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view.setUint16(6, txt ? 1 : 0)
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out.set(query.question, 12)
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if (txt) {
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let at = 12 + query.question.length
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// The answer's name points back to the question's (offset 12).
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view.setUint16(at, 0xc00c)
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view.setUint16(at + 2, TYPE_TXT)
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view.setUint16(at + 4, 1)
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view.setUint32(at + 6, txt.ttl)
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view.setUint16(at + 10, rdlength)
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at += 12
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for (const s of strings) {
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out[at++] = s.length
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out.set(s, at)
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at += s.length
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}
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}
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return out
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}
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