From 3d6ee5e376dcdce2a9387b30cae94f3b99f2230d Mon Sep 17 00:00:00 2001
From: wweir <wweir@foxmail.com>
Date: Tue, 10 Sep 2024 07:40:08 +0800
Subject: [PATCH] feat: support http(s)_proxy

---
 cmd/sower/main.go  | 30 +++++++++++++++++++----
 cmd/sower/proxy.go | 61 ++++++++++++++++++++++++++++++++++++++++++++--
 router/util.go     | 22 +++++++++++++++++
 3 files changed, 106 insertions(+), 7 deletions(-)
 create mode 100644 router/util.go

diff --git a/cmd/sower/main.go b/cmd/sower/main.go
index a9a2266..31ad8d2 100644
--- a/cmd/sower/main.go
+++ b/cmd/sower/main.go
@@ -34,10 +34,11 @@ var (
 		}
 
 		DNS struct {
-			Disable  bool   `default:"false" usage:"disable DNS proxy"`
-			Serve    string `default:"127.0.0.1" required:"true" usage:"dns server ip"`
-			Serve6   string `usage:"dns server ipv6, eg: ::1"`
-			Fallback string `default:"223.5.5.5" required:"true" usage:"fallback dns server"`
+			Disable    bool   `default:"false" usage:"disable DNS proxy"`
+			Serve      string `default:"127.0.0.1" required:"true" 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"`
 		}
 		Socks5 struct {
 			Disable bool   `default:"false" usage:"disable sock5 proxy"`
@@ -87,6 +88,25 @@ func init() {
 			Msg("Load config")
 	}
 
+	if conf.DNS.ServeIface != "" {
+		iface, err := net.InterfaceByName(conf.DNS.ServeIface)
+		log.DebugFatal(err).Str("iface", conf.DNS.ServeIface).Msg("get iface")
+		addrs, err := iface.Addrs()
+		log.InfoFatal(err).Str("iface", conf.DNS.ServeIface).Msg("get iface addrs")
+		for _, addr := range addrs {
+			ip, _, err := net.ParseCIDR(addr.String())
+			log.InfoFatal(err).Str("iface", conf.DNS.ServeIface).
+				Msg("parse iface addr: " + addr.String())
+
+			if ip.To4() != nil && conf.DNS.Serve == "" {
+				conf.DNS.Serve = ip.String()
+			}
+			if ip.To16() != nil && conf.DNS.Serve6 == "" {
+				conf.DNS.Serve = ip.String()
+			}
+		}
+	}
+
 	conf.Router.Direct.Rules = append(conf.Router.Direct.Rules,
 		conf.Remote.Addr, "**.in-addr.arpa", "**.ip6.arpa")
 	log.Info().
@@ -106,7 +126,6 @@ func main() {
 
 	if conf.DNS.Disable {
 		log.Info().Msg("DNS proxy disabled")
-
 	} else {
 		ips := make([]string, 0, 2)
 		if strings.TrimSpace(conf.DNS.Serve) != "" {
@@ -169,6 +188,7 @@ func loadRule(rule *suffixtree.Node, proxyDial router.ProxyDialFn, file, linePre
 	}
 	rule.GC()
 }
+
 func fetchRuleFile(proxyDial router.ProxyDialFn, file string) <-chan string {
 	if file == "" {
 		return make(chan string)
diff --git a/cmd/sower/proxy.go b/cmd/sower/proxy.go
index e078487..f81272b 100644
--- a/cmd/sower/proxy.go
+++ b/cmd/sower/proxy.go
@@ -150,7 +150,23 @@ func ServeSocks5(ln net.Listener, r *router.Router) {
 	go ServeSocks5(ln, r)
 	defer conn.Close()
 
-	addr, err := socks5.New().Unwrap(conn)
+	teeConn := teeconn.New(conn)
+
+	buf1 := make([]byte, 1)
+	if _, err := teeConn.Read(buf1); err != nil {
+		log.Warn().Err(err).
+			Msg("read socks5 version")
+		return
+	}
+
+	if buf1[0] != 5 {
+		teeConn.Reread()
+		serveHttpProxy(teeConn, r)
+		return
+	}
+
+	teeConn.Stop().Reread()
+	addr, err := socks5.New().Unwrap(teeConn)
 	if err != nil {
 		log.Warn().Err(err).
 			Msgf("parse socks5 target: %s", addr)
@@ -158,5 +174,46 @@ func ServeSocks5(ln net.Listener, r *router.Router) {
 	}
 
 	host, port := addr.(*socks5.AddrHead).Addr()
-	r.RouteHandle(conn, host, port)
+	r.RouteHandle(teeConn, host, port)
+}
+
+func serveHttpProxy(teeConn *teeconn.Conn, r *router.Router) {
+	req, err := http.ReadRequest(bufio.NewReader(teeConn))
+	if err != nil {
+		log.Warn().Err(err).
+			Msg("read http request")
+		return
+	}
+
+	teeConn.Stop()
+	switch req.Method {
+	case "CONNECT":
+		if _, err := teeConn.Write([]byte(req.Proto + " 200 Connection established\r\n\r\n")); err != nil {
+			log.Warn().Err(err).
+				Msg("write https proxy response")
+			return
+		}
+
+		host, port, err := router.ParseHostPort(req.Host, 443)
+		if err != nil {
+			log.Warn().Err(err).
+				Msg("parse https_proxy target")
+			return
+		}
+
+		rc, err := r.ProxyDial("tcp", host, port)
+		if err != nil {
+			log.Warn().Err(err).
+				Str("host", host).
+				Msg("dial proxy")
+			return
+		}
+		defer rc.Close()
+
+		relay.Relay(teeConn, rc)
+
+	default:
+		teeConn.Reread()
+		r.RouteHandle(teeConn, req.Host, 80)
+	}
 }
diff --git a/router/util.go b/router/util.go
new file mode 100644
index 0000000..790b76b
--- /dev/null
+++ b/router/util.go
@@ -0,0 +1,22 @@
+package router
+
+import (
+	"net"
+	"strconv"
+)
+
+func ParseHostPort(hostport string, defaultPort uint16) (string, uint16, error) {
+	host, port, err := net.SplitHostPort(hostport)
+	if err != nil {
+		return "", 0, err
+	}
+	if port == "" {
+		return host, defaultPort, nil
+	}
+
+	portInt, err := strconv.ParseUint(port, 10, 16)
+	if err != nil {
+		return "", 0, err
+	}
+	return host, uint16(portInt), nil
+}