add static hosts support

chain.go

@@ -18,6 +18,7 @@ var (
 type Chain struct {
 	isRoute    bool
 	Retries    int
+	Hosts      *Hosts
 	Resolver   Resolver
 	nodeGroups []*NodeGroup
 }
@@ -124,18 +125,7 @@ func (c *Chain) dial(addr string) (net.Conn, error) {
 		return nil, err
 	}
 
-	if c != nil && c.Resolver != nil {
+	addr = c.resolve(addr)
-		host, port, err := net.SplitHostPort(addr)
-		if err == nil {
-			addrs, er := c.Resolver.Resolve(host)
-			if er != nil {
-				log.Logf("[resolver] %s: %v", host, er)
-			}
-			if len(addrs) > 0 {
-				addr = net.JoinHostPort(addrs[0].IP.String(), port)
-			}
-		}
-	}
 
 	if route.IsEmpty() {
 		return net.DialTimeout("tcp", addr, DialTimeout)
@@ -154,6 +144,27 @@ func (c *Chain) dial(addr string) (net.Conn, error) {
 	return cc, nil
 }
 
+func (c *Chain) resolve(addr string) string {
+	host, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		return addr
+	}
+
+	if ip := c.Hosts.Lookup(host); ip != nil {
+		return net.JoinHostPort(ip.String(), port)
+	}
+	if c.Resolver != nil {
+		ips, err := c.Resolver.Resolve(host)
+		if err != nil {
+			log.Logf("[resolver] %s: %v", host, err)
+		}
+		if len(ips) > 0 {
+			return net.JoinHostPort(ips[0].String(), port)
+		}
+	}
+	return addr
+}
+
 // 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) {

cmd/gost/hosts.txt

@@ -0,0 +1,14 @@
+# The following lines are desirable for IPv4 capable hosts
+127.0.0.1       localhost
+
+# 127.0.1.1 is often used for the FQDN of the machine
+127.0.1.1       thishost.mydomain.org  thishost
+192.168.1.10    foo.mydomain.org       foo
+192.168.1.13    bar.mydomain.org       bar
+146.82.138.7    master.debian.org      master
+209.237.226.90  www.opensource.org
+
+# The following lines are desirable for IPv6 capable hosts
+::1             localhost ip6-localhost ip6-loopback
+ff02::1         ip6-allnodes
+ff02::2         ip6-allrouters

cmd/gost/main.go

@@ -6,6 +6,8 @@ import (
 	"flag"
 	"fmt"
 	"net"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"runtime"
 	"time"
@@ -57,6 +59,9 @@ func init() {
 }
 
 func main() {
+	go func() {
+		log.Log(http.ListenAndServe("localhost:6060", nil))
+	}()
 	// NOTE: as of 2.6, you can use custom cert/key files to initialize the default certificate.
 	config, err := tlsConfig(defaultCertFile, defaultKeyFile)
 	if err != nil {
@@ -336,12 +341,15 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 }
 
 func (r *route) serve() error {
-	chain, err := r.initChain()
+	baseChain, err := r.initChain()
 	if err != nil {
 		return err
 	}
 
 	for _, ns := range r.ServeNodes {
+		chain := &gost.Chain{}
+		*chain = *baseChain
+
 		node, err := gost.ParseNode(ns)
 		if err != nil {
 			return err
@@ -462,7 +470,6 @@ func (r *route) serve() error {
 		}
 
 		var handlerOptions []gost.HandlerOption
-
 		handlerOptions = append(handlerOptions,
 			gost.AddrHandlerOption(node.Addr),
 			gost.ChainHandlerOption(chain),
@@ -516,6 +523,14 @@ func (r *route) serve() error {
 		if gost.Debug {
 			log.Logf("[resolver]\n%v", chain.Resolver)
 		}
+
+		if f, _ := os.Open(node.Get("hosts")); f != nil {
+			chain.Hosts, err = gost.ParseHosts(f)
+			if err != nil {
+				log.Logf("[hosts] %s: %v", f.Name(), err)
+			}
+		}
+
 		go srv.Serve(handler)
 	}
 

hosts.go

@@ -0,0 +1,104 @@
+package gost
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"strings"
+
+	"github.com/go-log/log"
+)
+
+// Host is a static mapping from hostname to IP.
+type Host struct {
+	IP       net.IP
+	Hostname string
+	Aliases  []string
+}
+
+// Hosts is a static table lookup for hostnames.
+type Hosts struct {
+	hosts []Host
+}
+
+// NewHosts creates a Hosts with optional list of host
+func NewHosts(hosts ...Host) *Hosts {
+	return &Hosts{
+		hosts: hosts,
+	}
+}
+
+// ParseHosts parses host table from r.
+// For each host a single line should be present with the following information:
+// IP_address canonical_hostname [aliases...]
+// Fields of the entry are separated by any number of blanks and/or tab characters.
+// Text from a "#" character until the end of the line is a comment, and is ignored.
+func ParseHosts(r io.Reader) (*Hosts, error) {
+	hosts := NewHosts()
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if n := strings.IndexByte(line, '#'); n >= 0 {
+			line = line[:n]
+		}
+		line = strings.Replace(line, "\t", " ", -1)
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		var ss []string
+		for _, s := range strings.Split(line, " ") {
+			if s = strings.TrimSpace(s); s != "" {
+				ss = append(ss, s)
+			}
+		}
+		if len(ss) < 2 {
+			continue // invalid lines are ignored
+		}
+		ip := net.ParseIP(ss[0])
+		if ip == nil {
+			continue // invalid IP addresses are ignored
+		}
+		host := Host{
+			IP:       ip,
+			Hostname: ss[1],
+		}
+		if len(ss) > 2 {
+			host.Aliases = ss[2:]
+		}
+		hosts.AddHost(host)
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return hosts, nil
+}
+
+// AddHost adds host(s) to the host table.
+func (h *Hosts) AddHost(host ...Host) {
+	h.hosts = append(h.hosts, host...)
+}
+
+// Lookup searches the IP address corresponds to the given host from the host table.
+func (h *Hosts) Lookup(host string) (ip net.IP) {
+	if h == nil {
+		return
+	}
+	for _, h := range h.hosts {
+		if h.Hostname == host {
+			ip = h.IP
+			break
+		}
+		for _, alias := range h.Aliases {
+			if alias == host {
+				ip = h.IP
+				break
+			}
+		}
+	}
+	if ip != nil && Debug {
+		log.Logf("[hosts] hit: %s %s", host, ip.String())
+	}
+	return
+}

resolver.go

@@ -24,7 +24,7 @@ var (
 // It contains a list of name servers.
 type Resolver interface {
 	// Resolve returns a slice of that host's IPv4 and IPv6 addresses.
-	Resolve(host string) ([]net.IPAddr, error)
+	Resolve(host string) ([]net.IP, error)
 }
 
 // NameServer is a name server.
@@ -39,8 +39,8 @@ func (ns NameServer) String() string {
 	addr := ns.Addr
 	prot := ns.Protocol
 	host := ns.Hostname
-	if !strings.Contains(addr, ":") {
+	if _, port, _ := net.SplitHostPort(addr); port == "" {
-		addr += ":53"
+		addr = net.JoinHostPort(addr, "53")
 	}
 	if prot == "" {
 		prot = "udp"
@@ -49,8 +49,8 @@ func (ns NameServer) String() string {
 }
 
 type resolverCacheItem struct {
-	IPAddrs []net.IPAddr
+	IPs []net.IP
-	ts      int64
+	ts  int64
 }
 
 type resolver struct {
@@ -100,8 +100,8 @@ func (r *resolver) dial(ctx context.Context, ns NameServer) (net.Conn, error) {
 	var d net.Dialer
 
 	addr := ns.Addr
-	if !strings.Contains(addr, ":") {
+	if _, port, _ := net.SplitHostPort(addr); port == "" {
-		addr += ":53"
+		addr = net.JoinHostPort(addr, "53")
 	}
 	switch strings.ToLower(ns.Protocol) {
 	case "tcp":
@@ -125,28 +125,38 @@ func (r *resolver) dial(ctx context.Context, ns NameServer) (net.Conn, error) {
 	}
 }
 
-func (r *resolver) Resolve(name string) (addrs []net.IPAddr, err error) {
+func (r *resolver) Resolve(name string) (ips []net.IP, err error) {
+	if r == nil {
+		return
+	}
 	timeout := r.Timeout
 
-	addrs = r.loadCache(name)
+	if ip := net.ParseIP(name); ip != nil {
-	if len(addrs) > 0 {
+		return []net.IP{ip}, nil
+	}
+
+	ips = r.loadCache(name)
+	if len(ips) > 0 {
 		if Debug {
-			log.Logf("[resolver] cache hit: %s %v", name, addrs)
+			log.Logf("[resolver] cache hit: %s %v", name, ips)
 		}
 		return
 	}
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 
-	addrs, err = r.Resolver.LookupIPAddr(ctx, name)
+	addrs, err := r.Resolver.LookupIPAddr(ctx, name)
-	r.storeCache(name, addrs)
+	for _, addr := range addrs {
-	if len(addrs) > 0 && Debug {
+		ips = append(ips, addr.IP)
-		log.Logf("[resolver] %s %v", name, addrs)
+	}
+	r.storeCache(name, ips)
+	if len(ips) > 0 && Debug {
+		log.Logf("[resolver] %s %v", name, ips)
 	}
 	return
 }
 
-func (r *resolver) loadCache(name string) []net.IPAddr {
+func (r *resolver) loadCache(name string) []net.IP {
 	ttl := r.TTL
 	if ttl < 0 {
 		return nil
@@ -157,20 +167,20 @@ func (r *resolver) loadCache(name string) []net.IPAddr {
 		if item == nil || time.Since(time.Unix(item.ts, 0)) > ttl {
 			return nil
 		}
-		return item.IPAddrs
+		return item.IPs
 	}
 
 	return nil
 }
 
-func (r *resolver) storeCache(name string, addrs []net.IPAddr) {
+func (r *resolver) storeCache(name string, ips []net.IP) {
 	ttl := r.TTL
-	if ttl < 0 || name == "" || len(addrs) == 0 {
+	if ttl < 0 || name == "" || len(ips) == 0 {
 		return
 	}
 	r.mCache.Store(name, &resolverCacheItem{
-		IPAddrs: addrs,
+		IPs: ips,
-		ts:      time.Now().Unix(),
+		ts:  time.Now().Unix(),
 	})
 }
 
@@ -180,8 +190,8 @@ func (r *resolver) String() string {
 	}
 
 	b := &bytes.Buffer{}
-	fmt.Fprintf(b, "timeout %v\n", r.Timeout)
+	fmt.Fprintf(b, "Timeout %v\n", r.Timeout)
-	fmt.Fprintf(b, "ttl %v\n", r.TTL)
+	fmt.Fprintf(b, "TTL %v\n", r.TTL)
 	for i := range r.Servers {
 		fmt.Fprintln(b, r.Servers[i])
 	}

server.go

@@ -3,6 +3,7 @@ package gost
 import (
 	"io"
 	"net"
+	"sync"
 	"time"
 
 	"github.com/go-log/log"
@@ -132,15 +133,29 @@ func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
 	return tc, nil
 }
 
+var (
+	trPool = sync.Pool{
+		New: func() interface{} {
+			return make([]byte, 32*1024)
+		},
+	}
+)
+
 func transport(rw1, rw2 io.ReadWriter) error {
 	errc := make(chan error, 1)
 	go func() {
-		_, err := io.Copy(rw1, rw2)
+		buf := trPool.Get().([]byte)
+		defer trPool.Put(buf)
+
+		_, err := io.CopyBuffer(rw1, rw2, buf)
 		errc <- err
 	}()
 
 	go func() {
-		_, err := io.Copy(rw2, rw1)
+		buf := trPool.Get().([]byte)
+		defer trPool.Put(buf)
+
+		_, err := io.CopyBuffer(rw2, rw1, buf)
 		errc <- err
 	}()