sneak
21de2dd140
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.
124 lines
3.3 KiB
Go
124 lines
3.3 KiB
Go
// Package resolver provides iterative DNS resolution from root nameservers.
|
|
// It traces the full delegation chain from IANA root servers through TLD
|
|
// and domain nameservers, never relying on upstream recursive resolvers.
|
|
package resolver
|
|
|
|
import (
|
|
"context"
|
|
"log/slog"
|
|
|
|
"go.uber.org/fx"
|
|
|
|
"sneak.berlin/go/dnswatcher/internal/logger"
|
|
)
|
|
|
|
// Query status constants matching the state model.
|
|
const (
|
|
StatusOK = "ok"
|
|
StatusError = "error"
|
|
StatusNXDomain = "nxdomain"
|
|
StatusNoData = "nodata"
|
|
)
|
|
|
|
// MaxCNAMEDepth is the maximum CNAME chain depth to follow.
|
|
const MaxCNAMEDepth = 10
|
|
|
|
// Params contains dependencies for Resolver.
|
|
type Params struct {
|
|
fx.In
|
|
|
|
Logger *logger.Logger
|
|
}
|
|
|
|
// NameserverResponse holds one nameserver's response for a query.
|
|
type NameserverResponse struct {
|
|
Nameserver string
|
|
Records map[string][]string
|
|
Status string
|
|
Error string
|
|
}
|
|
|
|
// Resolver performs iterative DNS resolution from root servers.
|
|
type Resolver struct {
|
|
log *slog.Logger
|
|
}
|
|
|
|
// New creates a new Resolver instance for use with uber/fx.
|
|
func New(
|
|
_ fx.Lifecycle,
|
|
params Params,
|
|
) (*Resolver, error) {
|
|
return &Resolver{
|
|
log: params.Logger.Get(),
|
|
}, nil
|
|
}
|
|
|
|
// NewFromLogger creates a Resolver directly from an slog.Logger,
|
|
// useful for testing without the fx lifecycle.
|
|
func NewFromLogger(log *slog.Logger) *Resolver {
|
|
return &Resolver{log: log}
|
|
}
|
|
|
|
// FindAuthoritativeNameservers traces the delegation chain from
|
|
// root servers to discover all authoritative nameservers for the
|
|
// given domain. Returns the NS hostnames (e.g. ["ns1.example.com.",
|
|
// "ns2.example.com."]).
|
|
func (r *Resolver) FindAuthoritativeNameservers(
|
|
_ context.Context,
|
|
_ string,
|
|
) ([]string, error) {
|
|
return nil, ErrNotImplemented
|
|
}
|
|
|
|
// QueryNameserver queries a specific authoritative nameserver for
|
|
// all supported record types (A, AAAA, CNAME, MX, TXT, SRV, CAA,
|
|
// NS) for the given hostname. Returns a NameserverResponse with
|
|
// per-type record slices and a status indicating success or the
|
|
// type of failure.
|
|
func (r *Resolver) QueryNameserver(
|
|
_ context.Context,
|
|
_ string,
|
|
_ string,
|
|
) (*NameserverResponse, error) {
|
|
return nil, ErrNotImplemented
|
|
}
|
|
|
|
// QueryAllNameservers discovers the authoritative nameservers for
|
|
// the hostname's parent domain, then queries each one independently.
|
|
// Returns a map from nameserver hostname to its response.
|
|
func (r *Resolver) QueryAllNameservers(
|
|
_ context.Context,
|
|
_ string,
|
|
) (map[string]*NameserverResponse, error) {
|
|
return nil, ErrNotImplemented
|
|
}
|
|
|
|
// LookupNS returns the NS record set for a domain by performing
|
|
// iterative resolution. This is used for domain (apex) monitoring.
|
|
func (r *Resolver) LookupNS(
|
|
_ context.Context,
|
|
_ string,
|
|
) ([]string, error) {
|
|
return nil, ErrNotImplemented
|
|
}
|
|
|
|
// LookupAllRecords performs iterative resolution to find all DNS
|
|
// records for the given hostname, keyed by authoritative nameserver.
|
|
func (r *Resolver) LookupAllRecords(
|
|
_ context.Context,
|
|
_ string,
|
|
) (map[string]map[string][]string, error) {
|
|
return nil, ErrNotImplemented
|
|
}
|
|
|
|
// ResolveIPAddresses resolves a hostname to all IPv4 and IPv6
|
|
// addresses by querying all authoritative nameservers and following
|
|
// CNAME chains up to MaxCNAMEDepth. Returns a deduplicated list
|
|
// of IP address strings.
|
|
func (r *Resolver) ResolveIPAddresses(
|
|
_ context.Context,
|
|
_ string,
|
|
) ([]string, error) {
|
|
return nil, ErrNotImplemented
|
|
}
|