From 0e03605c37c84d89b825c095129da2e3076e6f65 Mon Sep 17 00:00:00 2001
From: wweir <wweir@foxmail.com>
Date: Sun, 9 Dec 2018 10:34:53 +0800
Subject: [PATCH] Support clear dns cache hook

---
 conf/conf.go    | 40 ++++++++++++++++++++++++++++++----------
 conf/sower.toml |  1 +
 proxy/server.go |  2 +-
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/conf/conf.go b/conf/conf.go
index f47d045..cedccd0 100644
--- a/conf/conf.go
+++ b/conf/conf.go
@@ -1,9 +1,13 @@
 package conf
 
 import (
+	"context"
 	"flag"
 	"net"
+	"os/exec"
+	"path/filepath"
 	"strconv"
+	"time"
 
 	"github.com/BurntSushi/toml"
 	"github.com/golang/glog"
@@ -11,14 +15,16 @@ import (
 )
 
 var Conf = struct {
-	ConfigFile  string
-	ServerPort  string   `toml:"server_port"`
-	ServerAddr  string   `toml:"server_addr"`
-	DnsServer   string   `toml:"dns_server"`
-	ClientIP    string   `toml:"client_ip"`
-	ClientIPNet net.IP   `toml:"-"`
-	BlockList   []string `toml:"blocklist"`
-	Verbose     int      `toml:"verbose"`
+	ConfigFile    string
+	ServerPort    string   `toml:"server_port"`
+	ServerAddr    string   `toml:"server_addr"`
+	DnsServer     string   `toml:"dns_server"`
+	ClientIP      string   `toml:"client_ip"`
+	ClientIPNet   net.IP   `toml:"-"`
+	ClearDnsCache string   `toml:"clear_dns_cache"`
+	BlockList     []string `toml:"blocklist"`
+	Suggestions   []string `toml:"suggestions"`
+	Verbose       int      `toml:"verbose"`
 }{}
 
 func init() {
@@ -46,6 +52,15 @@ var OnRefreash = []func() error{func() error {
 		return err
 	}
 	Conf.ClientIPNet = net.ParseIP(Conf.ClientIP)
+
+	// clear dns cache
+	if Conf.ClearDnsCache != "" {
+		ctx, _ := context.WithTimeout(context.TODO(), 5*time.Second)
+		if err := exec.CommandContext(ctx, "sh", "-c", Conf.ClearDnsCache).Run(); err != nil {
+			glog.Errorln(err)
+		}
+	}
+
 	// for glog
 	if err := flag.Set("v", strconv.Itoa(Conf.Verbose)); err != nil {
 		return err
@@ -53,13 +68,12 @@ var OnRefreash = []func() error{func() error {
 	return nil
 }}
 
-// watchConfigFile changes, fsnotify take too much cpu time, DIY
 func watchConfigFile() {
 	watcher, err := fsnotify.NewWatcher()
 	if err != nil {
 		glog.Fatalln(err)
 	}
-	if err := watcher.Add(Conf.ConfigFile); err != nil {
+	if err := watcher.Add(filepath.Dir(Conf.ConfigFile)); err != nil {
 		glog.Fatalln(err)
 	}
 
@@ -67,6 +81,12 @@ func watchConfigFile() {
 		for {
 			select {
 			case event := <-watcher.Events:
+				if event.Op == fsnotify.Rename {
+					if err := watcher.Add(Conf.ConfigFile); err != nil {
+						glog.Errorln(err)
+					}
+				}
+
 				glog.Infof("watch %s event: %v", Conf.ConfigFile, event)
 				for i := range OnRefreash {
 					if err := OnRefreash[i](); err != nil {
diff --git a/conf/sower.toml b/conf/sower.toml
index 419d3ba..5894acf 100644
--- a/conf/sower.toml
+++ b/conf/sower.toml
@@ -2,6 +2,7 @@ server_port="5533"
 server_addr="remote-server:5533" # replce it to remote server
 dns_server="114.114.114.114"
 # client_ip="192.168.0.1"
+# clear_dns_cache="sudo killall -HUP mDNSResponder"
 blocklist=[
     "*.google.com", # google
     "ocsp.pki.goog",
diff --git a/proxy/server.go b/proxy/server.go
index 3da855b..8989b4c 100644
--- a/proxy/server.go
+++ b/proxy/server.go
@@ -9,7 +9,7 @@ import (
 )
 
 func StartServer(port string) {
-	ln, err := quic.ListenAddr(":"+port, mockTlsPem(), nil)
+	ln, err := quic.ListenAddr(":"+port, mockTlsPem(), dialConf)
 	if err != nil {
 		glog.Fatalln(err)
 	}