fix: add support for dns timeout

go.mod

@@ -48,6 +48,8 @@ require (
 	gotest.tools v2.2.0+incompatible // indirect
 )
 
+require github.com/miekg/dns v1.1.43
+
 require (
 	github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 // indirect
 	github.com/DataDog/zstd v1.4.1 // indirect

go.sum

@@ -307,6 +307,8 @@ github.com/magiconair/properties v1.8.6/go.mod h1:y3VJvCyxH9uVvJTWEGAELF3aiYNyPK
 github.com/mattn/go-sqlite3 v1.14.9 h1:10HX2Td0ocZpYEjhilsuo6WWtUqttj2Kb0KtD86/KYA=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/miekg/dns v1.1.43 h1:JKfpVSCB84vrAmHzyrsxB5NAr5kLoMXZArPSw7Qlgyg=
+github.com/miekg/dns v1.1.43/go.mod h1:+evo5L0630/F6ca/Z9+GAqzhjGyn8/c+TBaOyfEl0V4=
 github.com/mimoo/StrobeGo v0.0.0-20181016162300-f8f6d4d2b643 h1:hLDRPB66XQT/8+wG9WsDpiCvZf1yKO7sz7scAjSlBa0=
 github.com/mimoo/StrobeGo v0.0.0-20181016162300-f8f6d4d2b643/go.mod h1:43+3pMjjKimDBf5Kr4ZFNGbLql1zKkbImw+fZbw3geM=
 github.com/minio/highwayhash v1.0.2 h1:Aak5U0nElisjDCfPSG79Tgzkn2gl66NxOMspRrKnA/g=
@@ -586,6 +588,8 @@ golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -638,6 +642,7 @@ golang.org/x/sys v0.0.0-20210104204734-6f8348627aad/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210225134936-a50acf3fe073/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210303074136-134d130e1a04/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210603081109-ebe580a85c40/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

p2p/transport.go

@@ -595,7 +595,10 @@ func resolveIPs(resolver IPResolver, c net.Conn) ([]net.IP, error) {
 		return nil, err
 	}
 
-	addrs, err := resolver.LookupIPAddr(context.Background(), host)
+	timeoutCtx, cancelFunc := context.WithTimeout(context.Background(), 1*time.Second)
+	defer cancelFunc()
+
+	addrs, err := resolver.LookupIPAddr(timeoutCtx, host)
 	if err != nil {
 		return nil, err
 	}

p2p/transport_test.go

@@ -1,11 +1,13 @@
 package p2p
 
 import (
+	"context"
 	"fmt"
 	"math/rand"
 	"net"
 	"reflect"
 	"runtime"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -14,6 +16,7 @@ import (
 	"github.com/line/ostracon/libs/protoio"
 	"github.com/line/ostracon/p2p/conn"
 	tmp2p "github.com/line/ostracon/proto/ostracon/p2p"
+	"github.com/miekg/dns"
 	"github.com/stretchr/testify/require"
 )
 
@@ -638,6 +641,22 @@ func TestTransportAddChannel(t *testing.T) {
 	}
 }
 
+func TestTransportResolveIPs(t *testing.T) {
+	go startFakeDNS()
+
+	r := &net.Resolver{
+		PreferGo: true,
+		Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+			d := net.Dialer{
+				Timeout: time.Millisecond * time.Duration(500),
+			}
+			return d.DialContext(ctx, network, "127.0.0.1:5355")
+		},
+	}
+	_, err := resolveIPs(r, &testTransportConn{})
+	require.Contains(t, err.Error(), "lookup test.local: i/o timeout")
+}
+
 // create listener
 func testSetupMultiplexTransport(t *testing.T) *MultiplexTransport {
 	var (
@@ -706,3 +725,49 @@ func (c *testTransportConn) SetWriteDeadline(_ time.Time) error {
 func (c *testTransportConn) Write(_ []byte) (int, error) {
 	return -1, fmt.Errorf("write() not implemented")
 }
+
+// fake dns server
+var records = map[string]string{
+	"test.local.": "192.168.0.2",
+}
+
+func parseQuery(m *dns.Msg) {
+	time.Sleep(5 * time.Minute)
+	for _, q := range m.Question {
+		switch q.Qtype {
+		case dns.TypeA:
+			ip := records[q.Name]
+			if ip != "" {
+				rr, err := dns.NewRR(fmt.Sprintf("%s A %s", q.Name, ip))
+				if err == nil {
+					m.Answer = append(m.Answer, rr)
+				}
+			}
+		}
+	}
+}
+
+func handleDnsRequest(w dns.ResponseWriter, r *dns.Msg) {
+	m := new(dns.Msg)
+	m.SetReply(r)
+	m.Compress = false
+	switch r.Opcode {
+	case dns.OpcodeQuery:
+		parseQuery(m)
+	}
+	_ = w.WriteMsg(m)
+}
+
+func startFakeDNS() {
+	// attach request handler func
+	dns.HandleFunc("local.", handleDnsRequest)
+
+	// start server
+	port := 5355
+	server := &dns.Server{Addr: ":" + strconv.Itoa(port), Net: "udp"}
+	err := server.ListenAndServe()
+	defer server.Shutdown() // nolint: errcheck
+	if err != nil {
+		panic(err.Error())
+	}
+}