From 3a750588b814eb618c3151b0ffe7871650cf55dd Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Sun, 16 Oct 2022 13:12:49 +0800
Subject: [PATCH] fix: when connection refused active health test

---
 adapter/outboundgroup/fallback.go    |  2 +-
 adapter/outboundgroup/groupbase.go   | 46 ++++++++++++++++++----------
 adapter/outboundgroup/loadbalance.go |  6 ++--
 adapter/outboundgroup/urltest.go     |  5 +--
 component/dialer/dialer.go           | 10 ++++++
 5 files changed, 47 insertions(+), 22 deletions(-)

diff --git a/adapter/outboundgroup/fallback.go b/adapter/outboundgroup/fallback.go
index 3e4c8927..ea9e13ae 100644
--- a/adapter/outboundgroup/fallback.go
+++ b/adapter/outboundgroup/fallback.go
@@ -31,7 +31,7 @@ func (f *Fallback) DialContext(ctx context.Context, metadata *C.Metadata, opts .
 		c.AppendToChains(f)
 		f.onDialSuccess()
 	} else {
-		f.onDialFailed()
+		f.onDialFailed(proxy.Type(), err)
 	}
 
 	return c, err
diff --git a/adapter/outboundgroup/groupbase.go b/adapter/outboundgroup/groupbase.go
index 7754d220..e96a5500 100644
--- a/adapter/outboundgroup/groupbase.go
+++ b/adapter/outboundgroup/groupbase.go
@@ -11,6 +11,7 @@ import (
 	"github.com/Dreamacro/clash/tunnel"
 	"github.com/dlclark/regexp2"
 	"go.uber.org/atomic"
+	"strings"
 	"sync"
 	"time"
 )
@@ -136,8 +137,13 @@ func (gb *GroupBase) URLTest(ctx context.Context, url string) (map[string]uint16
 	}
 }
 
-func (gb *GroupBase) onDialFailed() {
-	if gb.failedTesting.Load() {
+func (gb *GroupBase) onDialFailed(adapterType C.AdapterType, err error) {
+	if adapterType == C.Direct || adapterType == C.Compatible || adapterType == C.Reject || adapterType == C.Pass {
+		return
+	}
+
+	if strings.Contains(err.Error(), "connection refused") {
+		go gb.healthCheck()
 		return
 	}
 
@@ -157,26 +163,34 @@ func (gb *GroupBase) onDialFailed() {
 
 			log.Debugln("ProxyGroup: %s failed count: %d", gb.Name(), gb.failedTimes)
 			if gb.failedTimes >= gb.maxFailedTimes() {
-				gb.failedTesting.Store(true)
 				log.Warnln("because %s failed multiple times, active health check", gb.Name())
-				wg := sync.WaitGroup{}
-				for _, proxyProvider := range gb.providers {
-					wg.Add(1)
-					proxyProvider := proxyProvider
-					go func() {
-						defer wg.Done()
-						proxyProvider.HealthCheck()
-					}()
-				}
-
-				wg.Wait()
-				gb.failedTesting.Store(false)
-				gb.failedTimes = 0
+				gb.healthCheck()
 			}
 		}
 	}()
 }
 
+func (gb *GroupBase) healthCheck() {
+	if gb.failedTesting.Load() {
+		return
+	}
+
+	gb.failedTesting.Store(true)
+	wg := sync.WaitGroup{}
+	for _, proxyProvider := range gb.providers {
+		wg.Add(1)
+		proxyProvider := proxyProvider
+		go func() {
+			defer wg.Done()
+			proxyProvider.HealthCheck()
+		}()
+	}
+
+	wg.Wait()
+	gb.failedTesting.Store(false)
+	gb.failedTimes = 0
+}
+
 func (gb *GroupBase) failedIntervalTime() int64 {
 	return 5 * time.Second.Milliseconds()
 }
diff --git a/adapter/outboundgroup/loadbalance.go b/adapter/outboundgroup/loadbalance.go
index 430aed82..83af1e4f 100644
--- a/adapter/outboundgroup/loadbalance.go
+++ b/adapter/outboundgroup/loadbalance.go
@@ -82,17 +82,17 @@ func jumpHash(key uint64, buckets int32) int32 {
 
 // DialContext implements C.ProxyAdapter
 func (lb *LoadBalance) DialContext(ctx context.Context, metadata *C.Metadata, opts ...dialer.Option) (c C.Conn, err error) {
+	proxy := lb.Unwrap(metadata)
+
 	defer func() {
 		if err == nil {
 			c.AppendToChains(lb)
 			lb.onDialSuccess()
 		} else {
-			lb.onDialFailed()
+			lb.onDialFailed(proxy.Type(), err)
 		}
 	}()
 
-	proxy := lb.Unwrap(metadata)
-
 	c, err = proxy.DialContext(ctx, metadata, lb.Base.DialOptions(opts...)...)
 	return
 }
diff --git a/adapter/outboundgroup/urltest.go b/adapter/outboundgroup/urltest.go
index 9386e1ef..c4c5e219 100644
--- a/adapter/outboundgroup/urltest.go
+++ b/adapter/outboundgroup/urltest.go
@@ -34,12 +34,13 @@ func (u *URLTest) Now() string {
 
 // DialContext implements C.ProxyAdapter
 func (u *URLTest) DialContext(ctx context.Context, metadata *C.Metadata, opts ...dialer.Option) (c C.Conn, err error) {
-	c, err = u.fast(true).DialContext(ctx, metadata, u.Base.DialOptions(opts...)...)
+	proxy := u.fast(true)
+	c, err = proxy.DialContext(ctx, metadata, u.Base.DialOptions(opts...)...)
 	if err == nil {
 		c.AppendToChains(u)
 		u.onDialSuccess()
 	} else {
-		u.onDialFailed()
+		u.onDialFailed(proxy.Type(), err)
 	}
 	return c, err
 }
diff --git a/component/dialer/dialer.go b/component/dialer/dialer.go
index fa1b17a2..ea4d2ece 100644
--- a/component/dialer/dialer.go
+++ b/component/dialer/dialer.go
@@ -290,6 +290,7 @@ func concurrentDialContext(ctx context.Context, network string, ips []netip.Addr
 
 	connCount := len(ips)
 	var fallback dialResult
+	var primaryError error
 	for i := 0; i < connCount; i++ {
 		select {
 		case res := <-results:
@@ -303,6 +304,7 @@ func concurrentDialContext(ctx context.Context, network string, ips []netip.Addr
 				}
 			} else {
 				if res.isPrimary {
+					primaryError = res.error
 					preferCount.Add(-1)
 					if preferCount.Load() == 0 && fallback.done && fallback.error == nil {
 						return fallback.Conn, nil
@@ -321,6 +323,14 @@ func concurrentDialContext(ctx context.Context, network string, ips []netip.Addr
 		return fallback.Conn, nil
 	}
 
+	if primaryError != nil {
+		return nil, primaryError
+	}
+
+	if fallback.error != nil {
+		return nil, fallback.error
+	}
+
 	return nil, fmt.Errorf("all ips %v tcp shake hands failed", ips)
 }