fix(dns): fast-failed on RST

dns/cache.go

@@ -0,0 +1,31 @@
+package dns
+
+import (
+	"context"
+	"time"
+
+	"github.com/FloatTech/ttl"
+	"github.com/fumiama/terasu/ip"
+)
+
+var lookupTable = ttl.NewCache[string, []string](time.Hour)
+
+// LookupHost use default resolver with its fallback
+func LookupHost(ctx context.Context, host string) (addrs []string, err error) {
+	addrs = lookupTable.Get(host)
+	if len(addrs) == 0 {
+		addrs, err = DefaultResolver.LookupHost(ctx, host)
+		if err != nil {
+			if ip.IsIPv6Available.Get() {
+				addrs, err = IPv6Servers.lookupHostDoH(ctx, host)
+			} else {
+				addrs, err = IPv4Servers.lookupHostDoH(ctx, host)
+			}
+			if err != nil {
+				return nil, err
+			}
+		}
+		lookupTable.Set(host, addrs)
+	}
+	return
+}

dns/dns.go

@@ -14,15 +14,16 @@ import (
 )
 
 var (
+	// ErrNoDNSAvailable is reported when all servers failed to response
 	ErrNoDNSAvailable = errors.New("no dns available")
 )
 
-var defaultDialer = net.Dialer{
+var dnsDialer = net.Dialer{
 	Timeout: time.Second * 4,
 }
 
 func SetTimeout(t time.Duration) {
-	defaultDialer.Timeout = t
+	dnsDialer.Timeout = t
 }
 
 type dnsstat struct {
@@ -88,7 +89,7 @@ func (ds *DNSList) Add(c *DNSConfig) {
 	}
 }
 
-func (ds *DNSList) LookupHostFallback(ctx context.Context, host string) ([]string, error) {
+func (ds *DNSList) lookupHostDoH(ctx context.Context, host string) ([]string, error) {
 	ds.RLock()
 	defer ds.RUnlock()
 	// try to use DoH first
@@ -97,7 +98,7 @@ func (ds *DNSList) LookupHostFallback(ctx context.Context, host string) ([]strin
 			if !addr.e || !strings.HasPrefix(addr.a, "https://") { // disabled or is not DoH
 				continue
 			}
-			jr, err := lookupdoh(addr.a, host)
+			jr, err := lookupdoh(ctx, addr.a, host)
 			if err == nil {
 				hosts := jr.hosts()
 				if len(hosts) > 0 {
@@ -110,37 +111,34 @@ func (ds *DNSList) LookupHostFallback(ctx context.Context, host string) ([]strin
 	if addrs, ok := ds.b[host]; ok {
 		return addrs, nil
 	}
-	return net.DefaultResolver.LookupHost(ctx, host)
+	return nil, ErrNoDNSAvailable
 }
 
 func (ds *DNSList) DialContext(ctx context.Context, dialer *net.Dialer, firstFragmentLen uint8) (tlsConn *tls.Conn, err error) {
 	err = ErrNoDNSAvailable
 
 	if dialer == nil {
-		dialer = &defaultDialer
+		dialer = &dnsDialer
 	}
 
 	ds.RLock()
 	defer ds.RUnlock()
 
-	if dialer.Timeout != 0 {
-		var cancel context.CancelFunc
-		ctx, cancel = context.WithTimeout(ctx, dialer.Timeout)
-		defer cancel()
-	}
-
-	if !dialer.Deadline.IsZero() {
-		var cancel context.CancelFunc
-		ctx, cancel = context.WithDeadline(ctx, dialer.Deadline)
-		defer cancel()
-	}
-
 	var conn net.Conn
 	for host, addrs := range ds.m {
 		for _, addr := range addrs {
 			if !addr.e || strings.HasPrefix(addr.a, "https://") { // disabled or is DoH
 				continue
 			}
+			if dialer.Timeout != 0 {
+				var cancel context.CancelFunc
+				ctx, cancel = context.WithTimeout(context.Background(), dialer.Timeout)
+				defer cancel()
+			} else if !dialer.Deadline.IsZero() {
+				var cancel context.CancelFunc
+				ctx, cancel = context.WithDeadline(context.Background(), dialer.Deadline)
+				defer cancel()
+			}
 			conn, err = dialer.DialContext(ctx, "tcp", addr.a)
 			if err != nil {
 				addr.e = false // no need to acquire write lock

dns/dns_test.go

@@ -28,7 +28,7 @@ func TestResolverFallback(t *testing.T) {
 	t.Log("IsIPv6Available:", ip.IsIPv6Available.Get())
 
 	if ip.IsIPv6Available.Get() {
-		addrs, err := IPv6Servers.LookupHostFallback(context.TODO(), "huggingface.co")
+		addrs, err := IPv6Servers.lookupHostDoH(context.TODO(), "huggingface.co")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -37,7 +37,7 @@ func TestResolverFallback(t *testing.T) {
 			t.Fail()
 		}
 	}
-	addrs, err := IPv4Servers.LookupHostFallback(context.TODO(), "huggingface.co")
+	addrs, err := IPv4Servers.lookupHostDoH(context.TODO(), "huggingface.co")
 	if err != nil {
 		t.Fatal(err)
 	}

dns/doh.go

@@ -10,9 +10,7 @@ import (
 	"net/url"
 	"strconv"
 	"strings"
-	"time"
 
-	"github.com/FloatTech/ttl"
 	"golang.org/x/net/http2"
 
 	"github.com/fumiama/terasu"
@@ -65,23 +63,9 @@ func (jr *dohjsonresponse) hosts() []string {
 	return hosts
 }
 
-var lookupTable = ttl.NewCache[string, []string](time.Hour)
-
 var trsHTTP2ClientWithSystemDNS = http.Client{
 	Transport: &http2.Transport{
 		DialTLSContext: func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) {
-			if defaultDialer.Timeout != 0 {
-				var cancel context.CancelFunc
-				ctx, cancel = context.WithTimeout(ctx, defaultDialer.Timeout)
-				defer cancel()
-			}
-
-			if !defaultDialer.Deadline.IsZero() {
-				var cancel context.CancelFunc
-				ctx, cancel = context.WithDeadline(ctx, defaultDialer.Deadline)
-				defer cancel()
-			}
-
 			host, port, err := net.SplitHostPort(addr)
 			if err != nil {
 				return nil, err
@@ -100,7 +84,7 @@ var trsHTTP2ClientWithSystemDNS = http.Client{
 			var conn net.Conn
 			var tlsConn *tls.Conn
 			for _, a := range addrs {
-				conn, err = defaultDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
+				conn, err = dnsDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
 				if err != nil {
 					continue
 				}
@@ -111,7 +95,7 @@ var trsHTTP2ClientWithSystemDNS = http.Client{
 				}
 				_ = tlsConn.Close()
 				tlsConn = nil
-				conn, err = defaultDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
+				conn, err = dnsDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
 				if err != nil {
 					continue
 				}
@@ -128,18 +112,18 @@ var trsHTTP2ClientWithSystemDNS = http.Client{
 	},
 }
 
-func lookupdoh(server, u string) (jr dohjsonresponse, err error) {
+func lookupdoh(ctx context.Context, server, u string) (jr dohjsonresponse, err error) {
-	jr, err = lookupdohwithtype(server, u, preferreddohtype())
+	jr, err = lookupdohwithtype(ctx, server, u, preferreddohtype())
 	if err == nil {
 		return
 	}
 	if ip.IsIPv6Available.Get() {
-		jr, err = lookupdohwithtype(server, u, recordTypeA)
+		jr, err = lookupdohwithtype(ctx, server, u, recordTypeA)
 	}
 	return
 }
 
-func lookupdohwithtype(server, u string, typ recordType) (jr dohjsonresponse, err error) {
+func lookupdohwithtype(ctx context.Context, server, u string, typ recordType) (jr dohjsonresponse, err error) {
 	sb := strings.Builder{}
 	sb.WriteString(server)
 	sb.WriteString("?name=")
@@ -148,7 +132,7 @@ func lookupdohwithtype(server, u string, typ recordType) (jr dohjsonresponse, er
 		sb.WriteString("&type=")
 		sb.WriteString(strconv.Itoa(int(typ)))
 	}
-	req, err := http.NewRequest("GET", sb.String(), nil)
+	req, err := http.NewRequestWithContext(ctx, "GET", sb.String(), nil)
 	if err != nil {
 		return
 	}

go.mod

@@ -3,7 +3,7 @@ module github.com/fumiama/terasu
 go 1.20
 
 require (
-	github.com/FloatTech/ttl v0.0.0-20230307105452-d6f7b2b647d1
+	github.com/FloatTech/ttl v0.0.0-20250224045156-012b1463287d
 	github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7
 	golang.org/x/net v0.24.0
 )

go.sum

@@ -1,5 +1,5 @@
-github.com/FloatTech/ttl v0.0.0-20230307105452-d6f7b2b647d1 h1:g4pTnDJUW4VbJ9NvoRfUvdjDrHz/6QhfN/LoIIpICbo=
+github.com/FloatTech/ttl v0.0.0-20250224045156-012b1463287d h1:mUQ/c3wXKsUGa4Sg9DBy01APXKB68PmobhxOyaJI7lY=
-github.com/FloatTech/ttl v0.0.0-20230307105452-d6f7b2b647d1/go.mod h1:fHZFWGquNXuHttu9dUYoKuNbm3dzLETnIOnm1muSfDs=
+github.com/FloatTech/ttl v0.0.0-20250224045156-012b1463287d/go.mod h1:fHZFWGquNXuHttu9dUYoKuNbm3dzLETnIOnm1muSfDs=
 github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7 h1:S/ferNiehVjNaBMNNBxUjLtVmP/YWD6Yh79RfPv4ehU=
 github.com/RomiChan/syncx v0.0.0-20240418144900-b7402ffdebc7/go.mod h1:vD7Ra3Q9onRtojoY5sMCLQ7JBgjUsrXDnDKyFxqpf9w=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=

http/http.go

@@ -10,11 +10,8 @@ import (
 	"net/url"
 	"time"
 
-	"github.com/FloatTech/ttl"
-
 	"github.com/fumiama/terasu"
 	"github.com/fumiama/terasu/dns"
-	"github.com/fumiama/terasu/ip"
 )
 
 var (
@@ -23,49 +20,24 @@ var (
 )
 
 var defaultDialer = net.Dialer{
-	Timeout: time.Minute,
+	Timeout: 10 * time.Second,
 }
 
 func SetDefaultClientTimeout(t time.Duration) {
 	defaultDialer.Timeout = t
 }
 
-var lookupTable = ttl.NewCache[string, []string](time.Hour)
-
 var DefaultClient = http.Client{
 	Transport: &http.Transport{
 		Proxy: http.ProxyFromEnvironment,
 		DialTLSContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-			if defaultDialer.Timeout != 0 {
-				var cancel context.CancelFunc
-				ctx, cancel = context.WithTimeout(ctx, defaultDialer.Timeout)
-				defer cancel()
-			}
-
-			if !defaultDialer.Deadline.IsZero() {
-				var cancel context.CancelFunc
-				ctx, cancel = context.WithDeadline(ctx, defaultDialer.Deadline)
-				defer cancel()
-			}
-
 			host, port, err := net.SplitHostPort(addr)
 			if err != nil {
 				return nil, err
 			}
-			addrs := lookupTable.Get(host)
+			addrs, err := dns.LookupHost(ctx, host)
-			if len(addrs) == 0 {
+			if err != nil {
-				addrs, err = dns.DefaultResolver.LookupHost(ctx, host)
+				return nil, err
-				if err != nil {
-					if ip.IsIPv6Available.Get() {
-						addrs, err = dns.IPv6Servers.LookupHostFallback(ctx, host)
-					} else {
-						addrs, err = dns.IPv4Servers.LookupHostFallback(ctx, host)
-					}
-					if err != nil {
-						return nil, err
-					}
-				}
-				lookupTable.Set(host, addrs)
 			}
 			if len(addr) == 0 {
 				return nil, ErrEmptyHostAddress
@@ -73,6 +45,15 @@ var DefaultClient = http.Client{
 			var conn net.Conn
 			var tlsConn *tls.Conn
 			for _, a := range addrs {
+				if defaultDialer.Timeout != 0 {
+					var cancel context.CancelFunc
+					ctx, cancel = context.WithTimeout(context.Background(), defaultDialer.Timeout)
+					defer cancel()
+				} else if !defaultDialer.Deadline.IsZero() {
+					var cancel context.CancelFunc
+					ctx, cancel = context.WithDeadline(context.Background(), defaultDialer.Deadline)
+					defer cancel()
+				}
 				conn, err = defaultDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
 				if err != nil {
 					continue

http2/http2.go

@@ -10,12 +10,10 @@ import (
 	"net/url"
 	"time"
 
-	"github.com/FloatTech/ttl"
 	"golang.org/x/net/http2"
 
 	"github.com/fumiama/terasu"
 	"github.com/fumiama/terasu/dns"
-	"github.com/fumiama/terasu/ip"
 )
 
 var (
@@ -23,48 +21,23 @@ var (
 )
 
 var defaultDialer = net.Dialer{
-	Timeout: time.Minute,
+	Timeout: 10 * time.Second,
 }
 
 func SetDefaultClientTimeout(t time.Duration) {
 	defaultDialer.Timeout = t
 }
 
-var lookupTable = ttl.NewCache[string, []string](time.Hour)
-
 var DefaultClient = http.Client{
 	Transport: &http2.Transport{
 		DialTLSContext: func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) {
-			if defaultDialer.Timeout != 0 {
-				var cancel context.CancelFunc
-				ctx, cancel = context.WithTimeout(ctx, defaultDialer.Timeout)
-				defer cancel()
-			}
-
-			if !defaultDialer.Deadline.IsZero() {
-				var cancel context.CancelFunc
-				ctx, cancel = context.WithDeadline(ctx, defaultDialer.Deadline)
-				defer cancel()
-			}
-
 			host, port, err := net.SplitHostPort(addr)
 			if err != nil {
 				return nil, err
 			}
-			addrs := lookupTable.Get(host)
+			addrs, err := dns.LookupHost(ctx, host)
-			if len(addrs) == 0 {
+			if err != nil {
-				addrs, err = dns.DefaultResolver.LookupHost(ctx, host)
+				return nil, err
-				if err != nil {
-					if ip.IsIPv6Available.Get() {
-						addrs, err = dns.IPv6Servers.LookupHostFallback(ctx, host)
-					} else {
-						addrs, err = dns.IPv4Servers.LookupHostFallback(ctx, host)
-					}
-					if err != nil {
-						return nil, err
-					}
-				}
-				lookupTable.Set(host, addrs)
 			}
 			if len(addr) == 0 {
 				return nil, ErrEmptyHostAddress
@@ -72,6 +45,15 @@ var DefaultClient = http.Client{
 			var conn net.Conn
 			var tlsConn *tls.Conn
 			for _, a := range addrs {
+				if defaultDialer.Timeout != 0 {
+					var cancel context.CancelFunc
+					ctx, cancel = context.WithTimeout(context.Background(), defaultDialer.Timeout)
+					defer cancel()
+				} else if !defaultDialer.Deadline.IsZero() {
+					var cancel context.CancelFunc
+					ctx, cancel = context.WithDeadline(context.Background(), defaultDialer.Deadline)
+					defer cancel()
+				}
 				conn, err = defaultDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
 				if err != nil {
 					continue

terasu.go

@@ -6,7 +6,7 @@ import (
 	"unsafe"
 )
 
-var DefaultFirstFragmentLen uint8 = 4
+var DefaultFirstFragmentLen uint8 = 3
 
 // Use terasu in this TLS conn
 func Use(conn *tls.Conn) *Conn {