add bypass support for proxy chain

chain.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"strings"
 
 	"github.com/go-log/log"
 )
@@ -100,11 +101,7 @@ func (c *Chain) IsEmpty() bool {
 // Dial connects to the target address addr through the chain.
 // If the chain is empty, it will use the net.Dial directly.
 func (c *Chain) Dial(addr string) (conn net.Conn, err error) {
-	if c.IsEmpty() {
-		return net.DialTimeout("tcp", addr, DialTimeout)
-	}
-
-	for i := 0; i < c.Retries+1; i++ {
+	for i := 0; i < c.Retries; i++ {
 		conn, err = c.dial(addr)
 		if err == nil {
 			break
@@ -114,10 +111,13 @@ func (c *Chain) Dial(addr string) (conn net.Conn, err error) {
 }
 
 func (c *Chain) dial(addr string) (net.Conn, error) {
-	route, err := c.selectRoute()
+	route, err := c.selectRouteFor(addr)
 	if err != nil {
 		return nil, err
 	}
+	if route.IsEmpty() {
+		return net.DialTimeout("tcp", addr, DialTimeout)
+	}
 
 	conn, err := route.getConn()
 	if err != nil {
@@ -135,7 +135,7 @@ func (c *Chain) dial(addr string) (net.Conn, error) {
 // Conn obtains a handshaked connection to the last node of the chain.
 // If the chain is empty, it returns an ErrEmptyChain error.
 func (c *Chain) Conn() (conn net.Conn, err error) {
-	for i := 0; i < c.Retries+1; i++ {
+	for i := 0; i < c.Retries; i++ {
 		var route *Chain
 		route, err = c.selectRoute()
 		if err != nil {
@@ -228,3 +228,50 @@ func (c *Chain) selectRoute() (route *Chain, err error) {
 	}
 	return
 }
+
+// selectRouteFor selects route with bypass testing.
+func (c *Chain) selectRouteFor(addr string) (route *Chain, err error) {
+	if c.IsEmpty() || c.isRoute {
+		return c, nil
+	}
+
+	buf := bytes.Buffer{}
+	route = newRoute()
+	route.Retries = c.Retries
+
+	for _, group := range c.nodeGroups {
+		var node Node
+		node, err = group.Next()
+		if err != nil {
+			return
+		}
+
+		// NOTE: IPv6 will not work.
+		if strings.Contains(addr, ":") {
+			addr = strings.Split(addr, ":")[0]
+		}
+		if node.Bypass.Contains(addr) {
+			if Debug {
+				buf.WriteString(fmt.Sprintf("[%d@bypass: %s]", node.ID, addr))
+				log.Log("select route:", buf.String())
+			}
+			return
+		}
+
+		buf.WriteString(fmt.Sprintf("%s -> ", node.String()))
+
+		if node.Client.Transporter.Multiplex() {
+			node.DialOptions = append(node.DialOptions,
+				ChainDialOption(route),
+			)
+			route = newRoute() // cutoff the chain for multiplex.
+			route.Retries = c.Retries
+		}
+
+		route.AddNode(node)
+	}
+	if Debug {
+		log.Log("select route:", buf.String())
+	}
+	return
+}

cmd/gost/bypass.txt

@@ -0,0 +1,5 @@
+10.0.0.1
+192.168.0.0/24
+172.1.0.0/16
+192.168.100.190/32
+*.example.com

cmd/gost/main.go

@@ -92,7 +92,11 @@ type route struct {
 
 func (r *route) initChain() (*gost.Chain, error) {
 	chain := gost.NewChain()
+
 	chain.Retries = r.Retries
+	if chain.Retries == 0 {
+		chain.Retries = 1
+	}
 
 	gid := 1 // group ID
 
@@ -143,6 +147,17 @@ func (r *route) initChain() (*gost.Chain, error) {
 			ngroup.AddNode(nodes...)
 		}
 
+		var bypass *gost.Bypass
+		if peerCfg.Bypass != nil {
+			bypass = gost.NewBypassPatterns(peerCfg.Bypass.Patterns, peerCfg.Bypass.Reverse)
+		}
+		nodes = ngroup.Nodes()
+		for i := range nodes {
+			if nodes[i].Bypass == nil {
+				nodes[i].Bypass = bypass // use global bypass if local bypass does not exist.
+			}
+		}
+
 		chain.AddNodeGroup(ngroup)
 	}
 
@@ -297,9 +312,12 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 		Transporter: tr,
 	}
 
+	node.Bypass = parseBypass(node.Get("bypass"))
+
 	ips := parseIP(node.Get("ip"), sport)
 	for _, ip := range ips {
 		node.Addr = ip
+		// override the default node address
 		node.HandshakeOptions = append(handshakeOptions, gost.AddrHandshakeOption(ip))
 		nodes = append(nodes, node)
 	}
@@ -484,14 +502,9 @@ func (r *route) serve() error {
 			}
 		}
 
-		fBypass := node.Get("bypass")
-		if fBypass == "" {
-			fBypass = "bypass" // default bypass file
-		}
-
 		srv := &gost.Server{Listener: ln}
 		srv.Init(
-			gost.BypassServerOption(parseBypass(fBypass)),
+			gost.BypassServerOption(parseBypass(node.Get("bypass"))),
 		)
 		go srv.Serve(handler)
 	}
@@ -657,6 +670,12 @@ type peerConfig struct {
 	MaxFails    int      `json:"max_fails"`
 	FailTimeout int      `json:"fail_timeout"`
 	Nodes       []string `json:"nodes"`
+	Bypass      *bypass  `json:"bypass"` // global bypass
+}
+
+type bypass struct {
+	Reverse  bool     `json:"reverse"`
+	Patterns []string `json:"patterns"`
 }
 
 func loadPeerConfig(peer string) (config peerConfig, err error) {
@@ -694,16 +713,29 @@ func parseStrategy(s string) gost.Strategy {
 	}
 }
 
-func parseBypass(fpath string) (bypass *gost.Bypass) {
-	if fpath == "" {
-		return
+func parseBypass(s string) *gost.Bypass {
+	if s == "" {
+		return nil
 	}
-	f, err := os.Open(fpath)
+	var matchers []gost.Matcher
+	var reversed bool
+	if strings.HasPrefix(s, "~") {
+		reversed = true
+		s = strings.TrimLeft(s, "~")
+	}
+
+	f, err := os.Open(s)
 	if err != nil {
-		return
+		for _, s := range strings.Split(s, ",") {
+			s = strings.TrimSpace(s)
+			if s == "" {
+				continue
+			}
+			matchers = append(matchers, gost.NewMatcher(s))
+		}
+		return gost.NewBypass(matchers, reversed)
 	}
 
-	var matchers []gost.Matcher
 	scanner := bufio.NewScanner(f)
 	for scanner.Scan() {
 		line := scanner.Text()
@@ -716,6 +748,5 @@ func parseBypass(fpath string) (bypass *gost.Bypass) {
 		}
 		matchers = append(matchers, gost.NewMatcher(line))
 	}
-	bypass = gost.NewBypass(matchers, strings.HasPrefix(fpath, "~"))
-	return
+	return gost.NewBypass(matchers, reversed)
 }

cmd/gost/peer.json

@@ -6,5 +6,13 @@
         "socks5://:1081",
         "socks://:1082",
         "socks4a://:1083"
-    ]
+    ],
+    "bypass":{
+        "reverse": false,
+        "patterns": [
+            "10.0.0.1",
+            "192.168.0.0/24",
+            "*.example.com"
+        ]
+    }
 }

http.go

@@ -150,10 +150,15 @@ func (h *httpHandler) handleRequest(conn net.Conn, req *http.Request) {
 		}
 	}
 
+	route, err := h.options.Chain.selectRouteFor(req.Host)
+	if err != nil {
+		log.Logf("[http] %s -> %s : %s", conn.RemoteAddr(), req.Host, err)
+		return
+	}
 	// forward http request
-	lastNode := h.options.Chain.LastNode()
+	lastNode := route.LastNode()
 	if req.Method != http.MethodConnect && lastNode.Protocol == "http" {
-		h.forwardRequest(conn, req)
+		h.forwardRequest(conn, req, route)
 		return
 	}
 
@@ -162,7 +167,7 @@ func (h *httpHandler) handleRequest(conn net.Conn, req *http.Request) {
 		host += ":80"
 	}
 
-	cc, err := h.options.Chain.Dial(host)
+	cc, err := route.Dial(host)
 	if err != nil {
 		log.Logf("[http] %s -> %s : %s", conn.RemoteAddr(), host, err)
 
@@ -197,13 +202,13 @@ func (h *httpHandler) handleRequest(conn net.Conn, req *http.Request) {
 	log.Logf("[http] %s >-< %s", cc.LocalAddr(), host)
 }
 
-func (h *httpHandler) forwardRequest(conn net.Conn, req *http.Request) {
-	if h.options.Chain.IsEmpty() {
+func (h *httpHandler) forwardRequest(conn net.Conn, req *http.Request, route *Chain) {
+	if route.IsEmpty() {
 		return
 	}
-	lastNode := h.options.Chain.LastNode()
+	lastNode := route.LastNode()
 
-	cc, err := h.options.Chain.Conn()
+	cc, err := route.Conn()
 	if err != nil {
 		log.Logf("[http] %s -> %s : %s", conn.RemoteAddr(), lastNode.Addr, err)
 

node.go

@@ -25,6 +25,7 @@ type Node struct {
 	group            *NodeGroup
 	failCount        uint32
 	failTime         int64
+	Bypass           *Bypass
 }
 
 // ParseNode parses the node info.

socks.go

@@ -267,7 +267,7 @@ func (c *socks4Connector) Connect(conn net.Conn, addr string) (net.Conn, error)
 		return nil, err
 	}
 	if len(taddr.IP) == 0 {
-		taddr.IP = net.IPv4(0, 0, 0, 0)
+		taddr.IP = net.IPv4zero
 	}
 
 	req := gosocks4.NewRequest(gosocks4.CmdConnect,