From c79a9ee36d6dab1d161eac51ddfb81a7b556eaed Mon Sep 17 00:00:00 2001
From: nadoo <287492+nadoo@users.noreply.github.com>
Date: Fri, 14 Jul 2017 20:52:49 +0800
Subject: [PATCH] fixed a bug in proxy check which may leads to socket error:
 too many open files.

---
 main.go     | 36 ++++++++++++++----------------------
 proxy.go    |  4 ++--
 redir.go    |  2 --
 strategy.go |  4 ++++
 4 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/main.go b/main.go
index 0e7bbad..b214cfe 100644
--- a/main.go
+++ b/main.go
@@ -124,33 +124,25 @@ func main() {
 	}
 
 	var forwarders []Proxy
-	if len(flags.Forward) > 0 {
+	for _, chain := range flags.Forward {
+		var forward Proxy
 		var err error
-		for _, chain := range flags.Forward {
-			var forward Proxy
-			for _, url := range strings.Split(chain, ",") {
-				forward, err = ProxyFromURL(url, forward)
-				if err != nil {
-					log.Fatal(err)
-				}
-			}
-			forwarders = append(forwarders, forward)
-		}
-	}
-
-	for _, forward := range forwarders {
-		go check(forward, config.CheckSite, config.CheckDuration)
-	}
-
-	if len(flags.Listen) > 0 {
-		for _, listen := range flags.Listen {
-			local, err := ProxyFromURL(listen, forwarders...)
+		for _, url := range strings.Split(chain, ",") {
+			forward, err = ProxyFromURL(url, forward)
 			if err != nil {
 				log.Fatal(err)
 			}
-
-			go local.ListenAndServe()
 		}
+		forwarders = append(forwarders, forward)
+	}
+
+	for _, listen := range flags.Listen {
+		local, err := ProxyFromURL(listen, forwarders...)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		go local.ListenAndServe()
 	}
 
 	sigCh := make(chan os.Signal, 1)
diff --git a/proxy.go b/proxy.go
index 5c45b48..0c5c8c8 100644
--- a/proxy.go
+++ b/proxy.go
@@ -88,7 +88,7 @@ func ProxyFromURL(s string, forwarders ...Proxy) (Proxy, error) {
 	}
 
 	var proxy Proxy
-	if forwarders == nil || len(forwarders) == 0 {
+	if len(forwarders) == 0 {
 		proxy = newProxy(addr, Direct)
 	} else if len(forwarders) == 1 {
 		proxy = newProxy(addr, forwarders[0])
@@ -144,7 +144,7 @@ func check(p Proxy, target string, duration int) {
 			p.SetEnable(false)
 			continue
 		}
-		defer c.Close()
+		c.Close()
 
 		p.SetEnable(true)
 		logf("proxy %s check ok.", p.Addr())
diff --git a/redir.go b/redir.go
index aad33ed..2193ef0 100644
--- a/redir.go
+++ b/redir.go
@@ -64,8 +64,6 @@ func (s *redir) ListenAndServe() {
 			defer rc.Close()
 
 			logf("proxy-redir %s <-> %s", c.RemoteAddr(), tgt)
-			// go io.Copy(rc, c)
-			// io.Copy(c, rc)
 
 			_, _, err = relay(c, rc)
 			if err != nil {
diff --git a/strategy.go b/strategy.go
index 5dc1706..c094716 100644
--- a/strategy.go
+++ b/strategy.go
@@ -20,6 +20,10 @@ func newStrategyProxy(addr string, forwarders []Proxy) Proxy {
 		return newProxy(addr, forwarders[0])
 	}
 
+	for _, forward := range forwarders {
+		go check(forward, config.CheckSite, config.CheckDuration)
+	}
+
 	return &strategyProxy{addr: addr, forwarders: forwarders}
 }