fix(dns): serve interface parser

cmd/sower/main.go

@@ -37,7 +37,7 @@ var (
 
 		DNS struct {
 			Disable    bool   `default:"false" usage:"disable DNS proxy"`
-			Serve      string `default:"127.0.0.1" usage:"dns server ip"`
+			Serve      string `usage:"dns server ip"`
 			Serve6     string `usage:"dns server ipv6, eg: ::1"`
 			ServeIface string `usage:"use the IP in the net interface, if serve ip not setted. eg: eth0"`
 			Fallback   string `default:"223.5.5.5" required:"true" usage:"fallback dns server"`
@@ -78,6 +78,16 @@ func init() {
 	if err := aconfig.LoaderFor(&conf, aconfig.Config{
 		AllowUnknownFields: true,
 		FileFlag:           "f",
+		Files: []string{
+			"sower.hcl",
+			"sower.toml",
+			"sower.yaml",
+			"sower.yml",
+			"/etc/sower/sower.hcl",
+			"/etc/sower/sower.toml",
+			"/etc/sower/sower.yaml",
+			"/etc/sower/sower.yml",
+		},
 		FileDecoders: map[string]aconfig.FileDecoder{
 			".yml":  aconfigyaml.New(),
 			".yaml": aconfigyaml.New(),
@@ -98,7 +108,7 @@ func init() {
 		for _, addr := range addrs {
 			ip, _, err := net.ParseCIDR(addr.String())
 			log.InfoFatal(err).Str("iface", conf.DNS.ServeIface).
-				Msg("parse iface addr: " + addr.String())
+				Msg("parse iface IP: " + ip.String())
 
 			if ip.To4() != nil { // ipv4
 				if conf.DNS.Serve == "" {
@@ -126,7 +136,7 @@ func init() {
 }
 
 func main() {
-	proxyDial := GenProxyDial(conf.Remote.Type, conf.Remote.Addr, conf.Remote.Password)
+	proxyDial := GenProxyDial(conf.Remote.Type, conf.Remote.Addr, conf.Remote.Password, conf.DNS.Fallback)
 	r := router.NewRouter(conf.DNS.Serve, conf.DNS.Fallback, conf.Router.Country.MMDB, proxyDial)
 	r.BlockRule = suffixtree.NewNodeFromRules(conf.Router.Block.Rules...)
 	r.DirectRule = suffixtree.NewNodeFromRules(conf.Router.Direct.Rules...)

cmd/sower/proxy.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bufio"
+	"context"
 	"crypto/tls"
 	"net"
 	"net/http"
@@ -18,29 +19,43 @@ import (
 	"github.com/wweir/sower/transport/trojan"
 )
 
-func GenProxyDial(proxyType, proxyHost, proxyPassword string) router.ProxyDialFn {
+func GenProxyDial(proxyType, proxyHost, proxyPassword, dnsFallback string) router.ProxyDialFn {
 	var proxy transport.Transport
 	var dialFn func() (net.Conn, error)
 
+	dialer := &net.Dialer{
+		Resolver: &net.Resolver{
+			PreferGo: true,
+			Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+				d := net.Dialer{}
+				c, err := d.DialContext(ctx, "udp", net.JoinHostPort(dnsFallback, "53"))
+				if err != nil {
+					log.Warn().Err(err).Msg("dial fallback dns failed, use default dns setting")
+					c, err = d.DialContext(ctx, network, address)
+				}
+				return c, err
+			},
+		},
+	}
 	switch conf.Remote.Type {
 	case "sower":
 		proxy = sower.New(conf.Remote.Password)
 		tlsCfg := &tls.Config{}
 		dialFn = func() (net.Conn, error) {
-			return tls.Dial("tcp", net.JoinHostPort(proxyHost, "443"), tlsCfg)
+			return tls.DialWithDialer(dialer, "tcp", net.JoinHostPort(proxyHost, "443"), tlsCfg)
 		}
 
 	case "trojan":
 		proxy = trojan.New(conf.Remote.Password)
 		tlsCfg := &tls.Config{}
 		dialFn = func() (net.Conn, error) {
-			return tls.Dial("tcp", net.JoinHostPort(proxyHost, "443"), tlsCfg)
+			return tls.DialWithDialer(dialer, "tcp", net.JoinHostPort(proxyHost, "443"), tlsCfg)
 		}
 
 	case "socks5":
 		proxy = socks5.New()
 		dialFn = func() (net.Conn, error) {
-			return net.Dial("tcp", proxyHost)
+			return dialer.Dial("tcp", proxyHost)
 		}
 
 	default: