sneak
224b4bd73b
35 tests define the full resolver contract using live DNS queries against *.dns.sneak.cloud (Cloudflare). Tests cover: - FindAuthoritativeNameservers: iterative NS discovery, sorting, determinism, trailing dot handling, TLD and subdomain cases - QueryNameserver: A, AAAA, CNAME, MX, TXT, NXDOMAIN, per-NS response model with status field, sorted record values - QueryAllNameservers: independent per-NS queries, consistency verification, NXDOMAIN from all NS - LookupNS: NS record lookup matching FindAuthoritative - ResolveIPAddresses: basic, multi-A, IPv6, dual-stack, CNAME following, deduplication, sorting, NXDOMAIN returns empty - Context cancellation for all methods - Iterative resolution proof (resolves example.com from root) Also adds DNSSEC validation to planned future features in README.
115 lines
3.0 KiB
Go
115 lines
3.0 KiB
Go
// Package resolver provides iterative DNS resolution from root nameservers.
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// It traces the full delegation chain from IANA root servers through TLD
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// and domain nameservers, never relying on upstream recursive resolvers.
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package resolver
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import (
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"context"
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"log/slog"
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"go.uber.org/fx"
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"sneak.berlin/go/dnswatcher/internal/logger"
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)
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// Query status constants matching the state model.
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const (
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StatusOK = "ok"
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StatusError = "error"
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StatusNXDomain = "nxdomain"
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StatusNoData = "nodata"
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)
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// MaxCNAMEDepth is the maximum CNAME chain depth to follow.
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const MaxCNAMEDepth = 10
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// Params contains dependencies for Resolver.
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type Params struct {
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fx.In
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Logger *logger.Logger
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}
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// NameserverResponse holds one nameserver's response for a query.
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type NameserverResponse struct {
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Nameserver string
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Records map[string][]string
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Status string
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Error string
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}
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// Resolver performs iterative DNS resolution from root servers.
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type Resolver struct {
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log *slog.Logger
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}
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// New creates a new Resolver instance for use with uber/fx.
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func New(
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_ fx.Lifecycle,
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params Params,
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) (*Resolver, error) {
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return &Resolver{
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log: params.Logger.Get(),
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}, nil
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}
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// NewFromLogger creates a Resolver directly from an slog.Logger,
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// useful for testing without the fx lifecycle.
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func NewFromLogger(log *slog.Logger) *Resolver {
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return &Resolver{log: log}
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}
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// FindAuthoritativeNameservers traces the delegation chain from
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// root servers to discover all authoritative nameservers for the
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// given domain. Returns the NS hostnames (e.g. ["ns1.example.com.",
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// "ns2.example.com."]).
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func (r *Resolver) FindAuthoritativeNameservers(
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_ context.Context,
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_ string,
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) ([]string, error) {
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return nil, ErrNotImplemented
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}
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// QueryNameserver queries a specific authoritative nameserver for
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// all supported record types (A, AAAA, CNAME, MX, TXT, SRV, CAA,
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// NS) for the given hostname. Returns a NameserverResponse with
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// per-type record slices and a status indicating success or the
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// type of failure.
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func (r *Resolver) QueryNameserver(
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_ context.Context,
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_ string,
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_ string,
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) (*NameserverResponse, error) {
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return nil, ErrNotImplemented
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}
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// QueryAllNameservers discovers the authoritative nameservers for
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// the hostname's parent domain, then queries each one independently.
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// Returns a map from nameserver hostname to its response.
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func (r *Resolver) QueryAllNameservers(
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_ context.Context,
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_ string,
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) (map[string]*NameserverResponse, error) {
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return nil, ErrNotImplemented
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}
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// LookupNS returns the NS record set for a domain by performing
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// iterative resolution. This is used for domain (apex) monitoring.
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func (r *Resolver) LookupNS(
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_ context.Context,
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_ string,
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) ([]string, error) {
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return nil, ErrNotImplemented
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}
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// ResolveIPAddresses resolves a hostname to all IPv4 and IPv6
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// addresses by querying all authoritative nameservers and following
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// CNAME chains up to MaxCNAMEDepth. Returns a deduplicated list
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// of IP address strings.
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func (r *Resolver) ResolveIPAddresses(
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_ context.Context,
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_ string,
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) ([]string, error) {
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return nil, ErrNotImplemented
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}
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