Fast DNS implementation for Go
Features
- 0 Dependency
- Similar Interface with net/http
- Fast DoH Server Co-create with fasthttp
- Fast DNS Client with rich features
- Compatible metrics with coredns
- High Performance
- 0-allocs dns request parser
- 0-allocs dns records marshaller
- worker pool + message pool
- prefork + reuse_port + set_affinity
Getting Started
DNS Server
package main
import (
"log/slog"
"net"
"net/netip"
"os"
"github.com/phuslu/fastdns"
)
type DNSHandler struct {
Debug bool
}
func (h *DNSHandler) ServeDNS(rw fastdns.ResponseWriter, req *fastdns.Message) {
if h.Debug {
slog.Info("serve dns request", "domain", req.Domain, "class", req.Question.Class, "type", req.Question.Type)
}
switch req.Question.Type {
case fastdns.TypeA:
fastdns.HOST1(rw, req, 60, netip.AddrFrom4([4]byte{8, 8, 8, 8}))
case fastdns.TypeAAAA:
fastdns.HOST(rw, req, 60, []netip.Addr{netip.MustParseAddr("2001:4860:4860::8888")})
case fastdns.TypeCNAME:
fastdns.CNAME(rw, req, 60, []string{"dns.google"}, []netip.Addr{netip.MustParseAddr("8.8.8.8")})
case fastdns.TypeSRV:
fastdns.SRV(rw, req, 60, []net.SRV{{"www.google.com", 443, 1000, 1000}})
case fastdns.TypeNS:
fastdns.NS(rw, req, 60, []net.NS{{"ns1.google.com"}, {"ns2.google.com"}})
case fastdns.TypeMX:
fastdns.MX(rw, req, 60, []net.MX{{"mail.gmail.com", 10}, {"smtp.gmail.com", 10}})
case fastdns.TypeSOA:
fastdns.SOA(rw, req, 60, net.NS{"ns1.google"}, net.NS{"ns2.google"}, 60, 90, 90, 180, 60)
case fastdns.TypePTR:
fastdns.PTR(rw, req, 0, "ptr.google.com")
case fastdns.TypeTXT:
fastdns.TXT(rw, req, 60, "greetingfromgoogle")
default:
fastdns.Error(rw, req, fastdns.RcodeNXDomain)
}
}
func main() {
addr := ":53"
server := &fastdns.ForkServer{
Handler: &DNSHandler{
Debug: os.Getenv("DEBUG") != "",
},
Stats: &fastdns.CoreStats{
Prefix: "coredns_",
Family: "1",
Proto: "udp",
Server: "dns://" + addr,
Zone: ".",
},
ErrorLog: slog.Default(),
}
err := server.ListenAndServe(addr)
if err != nil {
slog.Error("dnsserver serve failed", "error", err)
}
}DoH Client
package main
import (
"context"
"crypto/tls"
"fmt"
"net/http"
"net/url"
"time"
"github.com/phuslu/fastdns"
)
func main() {
endpoint, _ := url.Parse("https://1.1.1.1/dns-query")
client := &fastdns.Client{
Addr: endpoint.String(),
Dialer: &fastdns.HTTPDialer{
Endpoint: endpoint,
Header: http.Header{
"content-type": {"application/dns-message"},
"user-agent": {"fastdns/1.0"},
},
Transport: &http.Transport{
ForceAttemptHTTP2: true,
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
TLSClientConfig: &tls.Config{
NextProtos: []string{"h2"},
InsecureSkipVerify: false,
ServerName: endpoint.Hostname(),
ClientSessionCache: tls.NewLRUClientSessionCache(1024),
},
},
},
}
ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
defer cancel()
fmt.Println(client.LookupHTTPS(ctx, "cloud.phus.lu"))
}DNS Client Tool
$ go install github.com/phuslu/fastdns/cmd/fastdig@master
$ fastdig ip.phus.lu @https://1.1.1.1/dns-query
; <<>> DiG 0.0.1-Fastdns <<>> ip.phus.lu
;; global options: +cmd +noedns
;; Got answer:
;; ->>HEADER<<- opcode: Query, status: Success, id: 2775
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;ip.phus.lu. IN A
;; ANSWER SECTION:
ip.phus.lu. 299 IN CNAME phus.lu.
phus.lu. 299 IN A 101.32.116.118
;; Query time: 15 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Apr 12 22:07:16 +08 2021
;; MSG SIZE rcvd: 58DoH Server Example
$ go install github.com/phuslu/fastdns/cmd/fastdoh@master
$ fastdoh :8080High Performance
A Performance result as below, for daily benchmark results see github actions
# go test -v -cpu=1 -run=none -benchmem -bench=.
goos: linux
goarch: amd64
pkg: github.com/phuslu/fastdns
cpu: AMD EPYC 7763 64-Core Processor
BenchmarkHOST1-4 56613120 21.09 ns/op 0 B/op 0 allocs/op
BenchmarkHOST-4 57722778 20.82 ns/op 0 B/op 0 allocs/op
BenchmarkCNAME-4 40001464 30.00 ns/op 0 B/op 0 allocs/op
BenchmarkSRV-4 26439794 44.84 ns/op 0 B/op 0 allocs/op
BenchmarkNS-4 22967035 52.28 ns/op 0 B/op 0 allocs/op
BenchmarkSOA-4 19650216 61.16 ns/op 0 B/op 0 allocs/op
BenchmarkPTR-4 50205879 30.12 ns/op 0 B/op 0 allocs/op
BenchmarkMX-4 39453458 29.81 ns/op 0 B/op 0 allocs/op
BenchmarkTXT-4 62278441 19.15 ns/op 0 B/op 0 allocs/op
BenchmarkParseMessage-4 83152729 14.84 ns/op 0 B/op 0 allocs/op
BenchmarkSetQuestion-4 37922407 31.28 ns/op 0 B/op 0 allocs/op
BenchmarkSetResponseHeader-4 336013587 3.583 ns/op 0 B/op 0 allocs/op
BenchmarkDecodeName-4 52855680 22.86 ns/op 0 B/op 0 allocs/op
BenchmarkAppendHOSTRecord-4 71025451 16.81 ns/op 0 B/op 0 allocs/op
BenchmarkAppendCNAMERecord-4 52953403 23.92 ns/op 0 B/op 0 allocs/op
BenchmarkAppendSRVRecord-4 30775414 36.37 ns/op 0 B/op 0 allocs/op
BenchmarkAppendNSRecord-4 27102512 43.92 ns/op 0 B/op 0 allocs/op
BenchmarkAppendSOARecord-4 21295884 56.13 ns/op 0 B/op 0 allocs/op
BenchmarkAppendPTRRecord-4 62573373 24.38 ns/op 0 B/op 0 allocs/op
BenchmarkAppendMXRecord-4 43072573 28.30 ns/op 0 B/op 0 allocs/op
BenchmarkAppendTXTRecord-4 100000000 11.15 ns/op 0 B/op 0 allocs/op
BenchmarkUpdateStats-4 40084848 29.85 ns/op 0 B/op 0 allocs/op
BenchmarkAppendOpenMetrics-4 110046 10824 ns/op 0 B/op 0 allocs/op
BenchmarkEncodeDomain-4 100000000 11.54 ns/op 0 B/op 0 allocs/op
PASS
ok github.com/phuslu/fastdns 30.430sHere is the real-world flamegraph 
when fastdns server reaches 1.4M QPS on a single machine with Xeon 4216 and Intel X710.
Acknowledgment
This dns server is inspired by fasthttp, rawdns and miekg/dns.