add dns support

Signed-off-by: arraykeys@gmail.com <arraykeys@gmail.com>

README.md

@@ -650,6 +650,8 @@ Then access to the local 8080 port is access to the proxy port 38080 on the VPS,
 
 ### How to use the source code?   
 use command cd to enter your go SRC directory and then  
+mkdir snail007  
+cd snail007   
 execute `git clone https://github.com/snail007/goproxy.git ./proxy`     
 Direct compilation: `go build`    
 execution: `go run *.go`    

README_ZH.md

@@ -656,8 +656,9 @@ KCP协议需要-B参数设置一个密码用于加密解密数据
 - 欢迎加群反馈...
 
 ### 如何使用源码? 
-建议go1.8,不保证>=1.9能用.   
+建议go1.8.5,不保证>=1.9能用.   
-cd进入你的go src目录,然后git clone https://github.com/snail007/goproxy.git ./proxy 即可.   
+cd进入你的go src目录,新建文件夹snail007,
+cd进入snail007,然后git clone https://github.com/snail007/goproxy.git ./proxy 即可.   
 编译直接:go build     
 运行: go run *.go    
 utils是工具包,service是具体的每个服务类.   

config.go

@@ -76,6 +76,8 @@ func initConfig() (err error) {
 	httpArgs.AuthURLTimeout = http.Flag("auth-timeout", "access 'auth-url' timeout milliseconds").Default("3000").Int()
 	httpArgs.AuthURLOkCode = http.Flag("auth-code", "access 'auth-url' success http code").Default("204").Int()
 	httpArgs.AuthURLRetry = http.Flag("auth-retry", "access 'auth-url' fail and retry count").Default("1").Int()
+	httpArgs.DNSAddress = http.Flag("dns-address", "if set this, proxy will use this dns for resolve doamin").Short('q').Default("").String()
+	httpArgs.DNSTTL = http.Flag("dns-ttl", "caching seconds of dns query result").Short('e').Default("300").Int()
 
 	//########tcp#########
 	tcp := app.Command("tcp", "proxy on tcp mode")
@@ -182,6 +184,8 @@ func initConfig() (err error) {
 	socksArgs.AuthURLTimeout = socks.Flag("auth-timeout", "access 'auth-url' timeout milliseconds").Default("3000").Int()
 	socksArgs.AuthURLOkCode = socks.Flag("auth-code", "access 'auth-url' success http code").Default("204").Int()
 	socksArgs.AuthURLRetry = socks.Flag("auth-retry", "access 'auth-url' fail and retry count").Default("0").Int()
+	socksArgs.DNSAddress = socks.Flag("dns-address", "if set this, proxy will use this dns for resolve doamin").Short('q').Default("").String()
+	socksArgs.DNSTTL = socks.Flag("dns-ttl", "caching seconds of dns query result").Short('e').Default("300").Int()
 
 	//parse args
 	serviceName := kingpin.MustParse(app.Parse(os.Args[1:]))

services/args.go

@@ -138,6 +138,8 @@ type HTTPArgs struct {
 	KCPMethod           *string
 	KCPKey              *string
 	LocalIPS            *[]string
+	DNSAddress          *string
+	DNSTTL              *int
 }
 type UDPArgs struct {
 	Parent              *string
@@ -182,6 +184,8 @@ type SocksArgs struct {
 	UDPParent      *string
 	UDPLocal       *string
 	LocalIPS       *[]string
+	DNSAddress     *string
+	DNSTTL         *int
 }
 
 func (a *TCPArgs) Protocol() string {

services/http.go

@@ -16,12 +16,13 @@ import (
 )
 
 type HTTP struct {
-	outPool   utils.OutPool
+	outPool        utils.OutPool
-	cfg       HTTPArgs
+	cfg            HTTPArgs
-	checker   utils.Checker
+	checker        utils.Checker
-	basicAuth utils.BasicAuth
+	basicAuth      utils.BasicAuth
-	sshClient *ssh.Client
+	sshClient      *ssh.Client
-	lockChn   chan bool
+	lockChn        chan bool
+	domainResolver utils.DomainResolver
 }
 
 func NewHTTP() Service {
@@ -74,6 +75,9 @@ func (s *HTTP) InitService() {
 	if *s.cfg.Parent != "" {
 		s.checker = utils.NewChecker(*s.cfg.HTTPTimeout, int64(*s.cfg.Interval), *s.cfg.Blocked, *s.cfg.Direct)
 	}
+	if *s.cfg.DNSAddress != "" {
+		(*s).domainResolver = utils.NewDomainResolver(*s.cfg.DNSAddress, *s.cfg.DNSTTL)
+	}
 	if *s.cfg.ParentType == "ssh" {
 		err := s.ConnectSSH()
 		if err != nil {
@@ -82,7 +86,7 @@ func (s *HTTP) InitService() {
 		go func() {
 			//循环检查ssh网络连通性
 			for {
-				conn, err := utils.ConnectHost(*s.cfg.Parent, *s.cfg.Timeout*2)
+				conn, err := utils.ConnectHost(s.domainResolver.MustResolve(*s.cfg.Parent), *s.cfg.Timeout*2)
 				if err == nil {
 					_, err = conn.Write([]byte{0})
 				}
@@ -211,7 +215,7 @@ func (s *HTTP) OutToTCP(useProxy bool, address string, inConn *net.Conn, req *ut
 				}
 			}
 		} else {
-			outConn, err = utils.ConnectHost(address, *s.cfg.Timeout)
+			outConn, err = utils.ConnectHost(s.domainResolver.MustResolve(address), *s.cfg.Timeout)
 		}
 		tryCount++
 		if err == nil || tryCount > maxTryCount {
@@ -304,7 +308,7 @@ func (s *HTTP) ConnectSSH() (err error) {
 	if s.sshClient != nil {
 		s.sshClient.Close()
 	}
-	s.sshClient, err = ssh.Dial("tcp", *s.cfg.Parent, &config)
+	s.sshClient, err = ssh.Dial("tcp", s.domainResolver.MustResolve(*s.cfg.Parent), &config)
 	<-s.lockChn
 	return
 }
@@ -318,7 +322,7 @@ func (s *HTTP) InitOutConnPool() {
 			*s.cfg.KCPMethod,
 			*s.cfg.KCPKey,
 			s.cfg.CertBytes, s.cfg.KeyBytes,
-			*s.cfg.Parent,
+			s.domainResolver.MustResolve(*s.cfg.Parent),
 			*s.cfg.Timeout,
 			*s.cfg.PoolSize,
 			*s.cfg.PoolSize*2,

services/socks.go

@@ -6,10 +6,10 @@ import (
 	"io/ioutil"
 	"log"
 	"net"
+	"runtime/debug"
 	"snail007/proxy/utils"
 	"snail007/proxy/utils/aes"
 	"snail007/proxy/utils/socks"
-	"runtime/debug"
 	"strings"
 	"time"
 
@@ -17,12 +17,13 @@ import (
 )
 
 type Socks struct {
-	cfg       SocksArgs
+	cfg            SocksArgs
-	checker   utils.Checker
+	checker        utils.Checker
-	basicAuth utils.BasicAuth
+	basicAuth      utils.BasicAuth
-	sshClient *ssh.Client
+	sshClient      *ssh.Client
-	lockChn   chan bool
+	lockChn        chan bool
-	udpSC     utils.ServerChannel
+	udpSC          utils.ServerChannel
+	domainResolver utils.DomainResolver
 }
 
 func NewSocks() Service {
@@ -77,6 +78,9 @@ func (s *Socks) CheckArgs() {
 }
 func (s *Socks) InitService() {
 	s.InitBasicAuth()
+	if *s.cfg.DNSAddress != "" {
+		(*s).domainResolver = utils.NewDomainResolver(*s.cfg.DNSAddress, *s.cfg.DNSTTL)
+	}
 	s.checker = utils.NewChecker(*s.cfg.Timeout, int64(*s.cfg.Interval), *s.cfg.Blocked, *s.cfg.Direct)
 	if *s.cfg.ParentType == "ssh" {
 		err := s.ConnectSSH()

utils/functions.go

@@ -431,7 +431,7 @@ func GetKCPBlock(method, key string) (block kcp.BlockCrypt) {
 	}
 	return
 }
-func HttpGet(URL string, timeout int) (body []byte, code int, err error) {
+func HttpGet(URL string, timeout int, host ...string) (body []byte, code int, err error) {
 	var tr *http.Transport
 	var client *http.Client
 	conf := &tls.Config{
@@ -445,7 +445,16 @@ func HttpGet(URL string, timeout int) (body []byte, code int, err error) {
 		client = &http.Client{Timeout: time.Millisecond * time.Duration(timeout), Transport: tr}
 	}
 	defer tr.CloseIdleConnections()
-	resp, err := client.Get(URL)
+
+	//resp, err := client.Get(URL)
+	req, err := http.NewRequest("GET", URL, nil)
+	if err != nil {
+		return
+	}
+	if len(host) == 1 {
+		req.Host = host[0]
+	}
+	resp, err := client.Do(req)
 	if err != nil {
 		return
 	}

utils/structs.go

@@ -15,6 +15,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	"src/github.com/miekg/dns"
 )
 
 type Checker struct {
@@ -815,3 +817,91 @@ func (c *ClientKeyRouter) GetKey() string {
 	}
 
 }
+
+type DomainResolver struct {
+	ttl         int
+	dnsAddrress string
+	data        ConcurrentMap
+}
+type DomainResolverItem struct {
+	ip        string
+	domain    string
+	expiredAt int64
+}
+
+func NewDomainResolver(dnsAddrress string, ttl int) DomainResolver {
+
+	return DomainResolver{
+		ttl:         ttl,
+		dnsAddrress: dnsAddrress,
+		data:        NewConcurrentMap(),
+	}
+}
+func (a *DomainResolver) MustResolve(address string) (ip string) {
+	ip, _ = a.Resolve(address)
+	return
+}
+func (a *DomainResolver) Resolve(address string) (ip string, err error) {
+	domain := address
+	port := ""
+	defer func() {
+		if port != "" {
+			ip = net.JoinHostPort(ip, port)
+		}
+	}()
+	if strings.Contains(domain, ":") {
+		domain, port, err = net.SplitHostPort(domain)
+		if err != nil {
+			return
+		}
+	}
+	item, ok := a.data.Get(domain)
+	if ok {
+		if (*item.(*DomainResolverItem)).expiredAt > time.Now().Unix() {
+			ip = (*item.(*DomainResolverItem)).ip
+			return
+		}
+
+	} else {
+		item = &DomainResolverItem{
+			domain: domain,
+		}
+		a.data.Set(domain, item)
+	}
+
+	if net.ParseIP(domain) != nil {
+		return domain, nil
+	}
+	c := new(dns.Client)
+	m := new(dns.Msg)
+	m.SetQuestion(dns.Fqdn(domain), dns.TypeA)
+	m.RecursionDesired = true
+	r, _, err := c.Exchange(m, a.dnsAddrress)
+	if r == nil {
+		return
+	}
+
+	if r.Rcode != dns.RcodeSuccess {
+		err = fmt.Errorf(" *** invalid answer name %s after A query for %s", domain, a.dnsAddrress)
+		return
+	}
+	for _, answer := range r.Answer {
+		if answer.Header().Rrtype == dns.TypeA {
+			info := strings.Fields(answer.String())
+			if len(info) >= 5 {
+				ip = info[4]
+				_item := item.(*DomainResolverItem)
+				(*_item).expiredAt = time.Now().Unix() + int64(a.ttl)
+				(*_item).ip = ip
+			}
+			return
+		}
+	}
+	return
+}
+func (a *DomainResolver) PrintData() {
+	for k, item := range a.data.Items() {
+		d := item.(*DomainResolverItem)
+		fmt.Printf("%s:ip[%s],domain[%s],expired at[%d]\n", k, (*d).ip, (*d).domain, (*d).expiredAt)
+	}
+}