update

add conditional compilation support
add multi core support

core/hy/resolver.go

@@ -0,0 +1,123 @@
+package hy
+
+import (
+	"crypto/tls"
+	"errors"
+	"net"
+	"net/url"
+	"strings"
+
+	"github.com/apernet/hysteria/core/utils"
+	rdns "github.com/folbricht/routedns"
+)
+
+var errInvalidSyntax = errors.New("invalid syntax")
+
+func setResolver(dns string) error {
+	if net.ParseIP(dns) != nil {
+		// Just an IP address, treat as UDP 53
+		dns = "udp://" + net.JoinHostPort(dns, "53")
+	}
+	var r rdns.Resolver
+	if strings.HasPrefix(dns, "udp://") {
+		// Standard UDP DNS resolver
+		dns = strings.TrimPrefix(dns, "udp://")
+		if dns == "" {
+			return errInvalidSyntax
+		}
+		if _, _, err := utils.SplitHostPort(dns); err != nil {
+			// Append the default DNS port
+			dns = net.JoinHostPort(dns, "53")
+		}
+		client, err := rdns.NewDNSClient("dns-udp", dns, "udp", rdns.DNSClientOptions{})
+		if err != nil {
+			return err
+		}
+		r = client
+	} else if strings.HasPrefix(dns, "tcp://") {
+		// Standard TCP DNS resolver
+		dns = strings.TrimPrefix(dns, "tcp://")
+		if dns == "" {
+			return errInvalidSyntax
+		}
+		if _, _, err := utils.SplitHostPort(dns); err != nil {
+			// Append the default DNS port
+			dns = net.JoinHostPort(dns, "53")
+		}
+		client, err := rdns.NewDNSClient("dns-tcp", dns, "tcp", rdns.DNSClientOptions{})
+		if err != nil {
+			return err
+		}
+		r = client
+	} else if strings.HasPrefix(dns, "https://") {
+		// DoH resolver
+		if dohURL, err := url.Parse(dns); err != nil {
+			return err
+		} else {
+			// Need to set bootstrap address to avoid loopback DNS lookup
+			dohIPAddr, err := net.ResolveIPAddr("ip", dohURL.Hostname())
+			if err != nil {
+				return err
+			}
+			client, err := rdns.NewDoHClient("doh", dns, rdns.DoHClientOptions{
+				BootstrapAddr: dohIPAddr.String(),
+			})
+			if err != nil {
+				return err
+			}
+			r = client
+		}
+	} else if strings.HasPrefix(dns, "tls://") {
+		// DoT resolver
+		dns = strings.TrimPrefix(dns, "tls://")
+		if dns == "" {
+			return errInvalidSyntax
+		}
+		dotHost, _, err := utils.SplitHostPort(dns)
+		if err != nil {
+			// Append the default DNS port
+			dns = net.JoinHostPort(dns, "853")
+		}
+		// Need to set bootstrap address to avoid loopback DNS lookup
+		dotIPAddr, err := net.ResolveIPAddr("ip", dotHost)
+		if err != nil {
+			return err
+		}
+		client, err := rdns.NewDoTClient("dot", dns, rdns.DoTClientOptions{
+			BootstrapAddr: dotIPAddr.String(),
+			TLSConfig:     new(tls.Config),
+		})
+		if err != nil {
+			return err
+		}
+		r = client
+	} else if strings.HasPrefix(dns, "quic://") {
+		// DoQ resolver
+		dns = strings.TrimPrefix(dns, "quic://")
+		if dns == "" {
+			return errInvalidSyntax
+		}
+		doqHost, _, err := utils.SplitHostPort(dns)
+		if err != nil {
+			// Append the default DNS port
+			dns = net.JoinHostPort(dns, "853")
+		}
+		// Need to set bootstrap address to avoid loopback DNS lookup
+		doqIPAddr, err := net.ResolveIPAddr("ip", doqHost)
+		if err != nil {
+			return err
+		}
+		client, err := rdns.NewDoQClient("doq", dns, rdns.DoQClientOptions{
+			BootstrapAddr: doqIPAddr.String(),
+		})
+		if err != nil {
+			return err
+		}
+		r = client
+	} else {
+		return errInvalidSyntax
+	}
+	cache := rdns.NewCache("cache", r, rdns.CacheOptions{})
+	net.DefaultResolver = rdns.NewNetResolver(cache)
+	return nil
+}