From 36c25a8f9c40a47a9bcba500c9c413dbd1a2b9d0 Mon Sep 17 00:00:00 2001
From: Jason <xjasonlyu@gmail.com>
Date: Sat, 20 Jul 2019 15:14:40 +0800
Subject: [PATCH] add an option to set cache size

---
 cmd/tun2socks/main.go         | 1 +
 cmd/tun2socks/main_fakedns.go | 3 ++-
 common/dns/fakedns/server.go  | 6 ++----
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/cmd/tun2socks/main.go b/cmd/tun2socks/main.go
index 72f1a9c..087da93 100644
--- a/cmd/tun2socks/main.go
+++ b/cmd/tun2socks/main.go
@@ -50,6 +50,7 @@ type CmdArgs struct {
 	FakeIPRange          *string
 	FakeDnsAddr          *string
 	FakeDnsHosts         *string
+	DnsCacheSize         *int
 	ExceptionApps        *string
 	ExceptionSendThrough *string
 	Stats                *bool
diff --git a/cmd/tun2socks/main_fakedns.go b/cmd/tun2socks/main_fakedns.go
index f5c71bc..31c58e3 100644
--- a/cmd/tun2socks/main_fakedns.go
+++ b/cmd/tun2socks/main_fakedns.go
@@ -13,10 +13,11 @@ func init() {
 	args.FakeDnsAddr = flag.String("fakeDnsAddr", ":53", "listen address of fake DNS")
 	args.FakeIPRange = flag.String("fakeIPRange", "198.18.0.1/16", "fake IP CIDR range for DNS")
 	args.FakeDnsHosts = flag.String("fakeDnsHosts", "", "Hosts mapping, e.g. 'a.com=1.1.1.1,b.net=2.2.2.2'")
+	args.DnsCacheSize = flag.Int("dnsCacheSize", 100, "Size of LRU-Cache to store DNS msg")
 
 	addPostFlagsInitFn(func() {
 		if *args.EnableFakeDns {
-			fakeDnsServer, err := fakedns.NewServer(*args.FakeIPRange, *args.FakeDnsHosts)
+			fakeDnsServer, err := fakedns.NewServer(*args.FakeIPRange, *args.FakeDnsHosts, *args.DnsCacheSize)
 			if err != nil {
 				panic("create fake dns server error")
 			}
diff --git a/common/dns/fakedns/server.go b/common/dns/fakedns/server.go
index 3a60c49..11094b2 100644
--- a/common/dns/fakedns/server.go
+++ b/common/dns/fakedns/server.go
@@ -18,8 +18,6 @@ const (
 
 // var cacheDuration = time.Duration(dnsDefaultTTL) * time.Second
 
-var cacheSize = 100
-
 type Server struct {
 	*D.Server
 	c *cache.Cache
@@ -68,7 +66,7 @@ func (s *Server) IPToHost(ip net.IP) (string, bool) {
 	return strings.TrimRight(fqdn, "."), true
 }
 
-func NewServer(fakeIPRange, hostsLine string) (*Server, error) {
+func NewServer(fakeIPRange, hostsLine string, size int) (*Server, error) {
 	_, ipnet, err := net.ParseCIDR(fakeIPRange)
 	if err != nil {
 		return nil, err
@@ -79,7 +77,7 @@ func NewServer(fakeIPRange, hostsLine string) (*Server, error) {
 	}
 
 	hosts := lineToHosts(hostsLine)
-	cacheItem := cache.New(cacheSize)
+	cacheItem := cache.New(size)
 	handler := newHandler(hosts, cacheItem, pool)
 
 	return &Server{