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
A fastdns server example
package main
import (
"log"
"net"
"os"
"github.com/phuslu/fastdns"
)
type DNSHandler struct {
Debug bool
}
func (h *DNSHandler) ServeDNS(rw fastdns.ResponseWriter, req *fastdns.Message) {
if h.Debug {
log.Printf("%s: CLASS %s TYPE %s\n", req.Domain, req.Question.Class, req.Question.Type)
}
switch req.Question.Type {
case fastdns.TypeA:
fastdns.HOST(rw, req, 60, []net.IP{{8, 8, 8, 8}})
case fastdns.TypeAAAA:
fastdns.HOST(rw, req, 60, []net.IP{net.ParseIP("2001:4860:4860::8888")})
case fastdns.TypeCNAME:
fastdns.CNAME(rw, req, 60, []string{"dns.google"}, []net.IP{{8, 8, 8, 8}, {8, 8, 4, 4}})
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: log.Default(),
}
err := server.ListenAndServe(addr)
if err != nil {
log.Fatalf("dnsserver error: %+v", err)
}
}
DoH Server
see https://github.com/phuslu/fastdns/tree/master/fastdoh
DNS Client
$ go get github.com/phuslu/fastdns/cmd/fastdig
$ fastdig ip.phus.lu @8.8.8.8
; <<>> 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: 58
High 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: Intel(R) Xeon(R) Silver 4216 CPU @ 2.10GHz
BenchmarkHOST 39442191 30.31 ns/op 0 B/op 0 allocs/op
BenchmarkCNAME 22563691 53.23 ns/op 0 B/op 0 allocs/op
BenchmarkSRV 20890515 57.63 ns/op 0 B/op 0 allocs/op
BenchmarkNS 16634973 71.98 ns/op 0 B/op 0 allocs/op
BenchmarkSOA 14635425 82.16 ns/op 0 B/op 0 allocs/op
BenchmarkPTR 27980914 42.96 ns/op 0 B/op 0 allocs/op
BenchmarkMX 24721230 48.75 ns/op 0 B/op 0 allocs/op
BenchmarkTXT 39824239 30.14 ns/op 0 B/op 0 allocs/op
BenchmarkParseMessage 50639167 23.86 ns/op 0 B/op 0 allocs/op
BenchmarkSetRequestQustion 26985039 46.08 ns/op 0 B/op 0 allocs/op
BenchmarkSetResponseHeader 175744434 6.833 ns/op 0 B/op 0 allocs/op
BenchmarkDecodeName 33319760 36.07 ns/op 0 B/op 0 allocs/op
BenchmarkAppendHOSTRecord 55649703 21.56 ns/op 0 B/op 0 allocs/op
BenchmarkAppendCNAMERecord 29943513 40.04 ns/op 0 B/op 0 allocs/op
BenchmarkAppendSRVRecord 26827544 45.00 ns/op 0 B/op 0 allocs/op
BenchmarkAppendNSRecord 20113075 59.70 ns/op 0 B/op 0 allocs/op
BenchmarkAppendSOARecord 17054136 69.81 ns/op 0 B/op 0 allocs/op
BenchmarkAppendPTRRecord 36748305 32.60 ns/op 0 B/op 0 allocs/op
BenchmarkAppendMXRecord 34203414 35.04 ns/op 0 B/op 0 allocs/op
BenchmarkAppendTXTRecord 65836453 18.22 ns/op 0 B/op 0 allocs/op
BenchmarkUpdateStats 14161730 84.78 ns/op 0 B/op 0 allocs/op
BenchmarkEncodeDomain 63253357 19.27 ns/op 0 B/op 0 allocs/op
PASS
ok github.com/phuslu/fastdns 19.026s
Here is the real-world flamegraph 
Acknowledgment
This dns server is inspired by fasthttp, rawdns and miekg/dns.
