From d0c829c578445b64041829a0633f6526055398a5 Mon Sep 17 00:00:00 2001
From: Dreamacro <8615343+Dreamacro@users.noreply.github.com>
Date: Thu, 1 Apr 2021 21:20:44 +0800
Subject: [PATCH] Fix: domain dns should follow hosts config, close #1318

---
 component/resolver/resolver.go | 20 +++++++++++++-------
 dns/client.go                  |  4 ++--
 dns/doh.go                     |  5 +++--
 3 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/component/resolver/resolver.go b/component/resolver/resolver.go
index 356bc660..d10e39cb 100644
--- a/component/resolver/resolver.go
+++ b/component/resolver/resolver.go
@@ -3,6 +3,7 @@ package resolver
 import (
 	"context"
 	"errors"
+	"math/rand"
 	"net"
 	"strings"
 	"time"
@@ -66,7 +67,7 @@ func ResolveIPv4(host string) (net.IP, error) {
 		return nil, ErrIPNotFound
 	}
 
-	return ipAddrs[0], nil
+	return ipAddrs[rand.Intn(len(ipAddrs))], nil
 }
 
 // ResolveIPv6 with a host, return ipv6
@@ -102,20 +103,20 @@ func ResolveIPv6(host string) (net.IP, error) {
 		return nil, ErrIPNotFound
 	}
 
-	return ipAddrs[0], nil
+	return ipAddrs[rand.Intn(len(ipAddrs))], nil
 }
 
-// ResolveIP with a host, return ip
-func ResolveIP(host string) (net.IP, error) {
+// ResolveIPWithResolver same as ResolveIP, but with a resolver
+func ResolveIPWithResolver(host string, r Resolver) (net.IP, error) {
 	if node := DefaultHosts.Search(host); node != nil {
 		return node.Data.(net.IP), nil
 	}
 
-	if DefaultResolver != nil {
+	if r != nil {
 		if DisableIPv6 {
-			return DefaultResolver.ResolveIPv4(host)
+			return r.ResolveIPv4(host)
 		}
-		return DefaultResolver.ResolveIP(host)
+		return r.ResolveIP(host)
 	} else if DisableIPv6 {
 		return ResolveIPv4(host)
 	}
@@ -132,3 +133,8 @@ func ResolveIP(host string) (net.IP, error) {
 
 	return ipAddr.IP, nil
 }
+
+// ResolveIP with a host, return ip
+func ResolveIP(host string) (net.IP, error) {
+	return ResolveIPWithResolver(host, DefaultResolver)
+}
diff --git a/dns/client.go b/dns/client.go
index 151bee24..405b3a98 100644
--- a/dns/client.go
+++ b/dns/client.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/resolver"
 
 	D "github.com/miekg/dns"
 )
@@ -28,8 +29,7 @@ func (c *client) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, err
 		// a default ip dns
 		ip = net.ParseIP(c.host)
 	} else {
-		var err error
-		if ip, err = c.r.ResolveIP(c.host); err != nil {
+		if ip, err = resolver.ResolveIPWithResolver(c.host, c.r); err != nil {
 			return nil, fmt.Errorf("use default dns resolve failed: %w", err)
 		}
 	}
diff --git a/dns/doh.go b/dns/doh.go
index ee26e7c8..247e0704 100644
--- a/dns/doh.go
+++ b/dns/doh.go
@@ -9,6 +9,7 @@ import (
 	"net/http"
 
 	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/resolver"
 
 	D "github.com/miekg/dns"
 )
@@ -83,12 +84,12 @@ func newDoHClient(url string, r *Resolver) *dohClient {
 					return nil, err
 				}
 
-				ip, err := r.ResolveIPv4(host)
+				ip, err := resolver.ResolveIPWithResolver(host, r)
 				if err != nil {
 					return nil, err
 				}
 
-				return dialer.DialContext(ctx, "tcp4", net.JoinHostPort(ip.String(), port))
+				return dialer.DialContext(ctx, "tcp", net.JoinHostPort(ip.String(), port))
 			},
 		},
 	}