all: new feature connection pool

conf/frpc.ini

@@ -22,6 +22,8 @@ local_port = 22
 use_encryption = true
 # default is false
 use_gzip = false
+# connections will be established in advance, default value is zero
+pool_count = 10
 
 # Resolve your domain names to [server_addr] so you can use http://web01.yourdomain.com to browse web01 and http://web02.yourdomain.com to browse web02, the domains are set in frps.ini
 [web01]
@@ -29,6 +31,7 @@ type = http
 local_ip = 127.0.0.1
 local_port = 80
 use_gzip = true
+pool_count = 20
 
 [web02]
 type = http

conf/frps.ini

@@ -15,6 +15,8 @@ log_max_days = 3
 # if you enable privilege mode, frpc can create a proxy without pre-configure in frps when privilege_token is correct
 privilege_mode = true
 privilege_token = 12345678
+# pool_count in each proxy will change to max_pool_count if they exceed the maximum value
+max_pool_count = 100
 
 # ssh is the proxy name, client will use this name and auth_token to connect to server
 [ssh]

src/frp/cmd/frpc/control.go

@@ -142,6 +142,7 @@ func loginToServer(cli *client.ProxyClient) (c *conn.Conn, err error) {
 		ProxyName:     cli.Name,
 		UseEncryption: cli.UseEncryption,
 		UseGzip:       cli.UseGzip,
+		PoolCount:     cli.PoolCount,
 		PrivilegeMode: cli.PrivilegeMode,
 		ProxyType:     cli.Type,
 		Timestamp:     nowTime,
@@ -181,7 +182,7 @@ func loginToServer(cli *client.ProxyClient) (c *conn.Conn, err error) {
 		return c, fmt.Errorf("%s", ctlRes.Msg)
 	}
 
-	log.Debug("ProxyName [%s], connect to server [%s:%d] success!", cli.Name, client.ServerAddr, client.ServerPort)
+	log.Info("ProxyName [%s], connect to server [%s:%d] success!", cli.Name, client.ServerAddr, client.ServerPort)
 	return
 }
 
@@ -199,5 +200,5 @@ func heartbeatSender(c *conn.Conn, msgSendChan chan interface{}) {
 			break
 		}
 	}
-	log.Debug("Heartbeat goroutine exit")
+	log.Info("Heartbeat goroutine exit")
 }

src/frp/cmd/frps/control.go

@@ -276,6 +276,13 @@ func doLogin(req *msg.ControlReq, c *conn.Conn) (ret int64, info string) {
 		// set infomations from frpc
 		s.UseEncryption = req.UseEncryption
 		s.UseGzip = req.UseGzip
+		if req.PoolCount > server.MaxPoolCount {
+			s.PoolCount = server.MaxPoolCount
+		} else if req.PoolCount < 0 {
+			s.PoolCount = 0
+		} else {
+			s.PoolCount = req.PoolCount
+		}
 
 		// start proxy and listen for user connections, no block
 		err := s.Start(c)

src/frp/models/client/config.go

@@ -147,10 +147,21 @@ func LoadConf(confFile string) (err error) {
 				proxyClient.PrivilegeMode = true
 			}
 
+			// pool_count
+			proxyClient.PoolCount = 0
+			tmpStr, ok = section["pool_count"]
+			if ok {
+				tmpInt, err := strconv.ParseInt(tmpStr, 10, 64)
+				if err != nil || tmpInt < 0 {
+					return fmt.Errorf("Parse conf error: proxy [%s] pool_count error", proxyClient.Name)
+				}
+				proxyClient.PoolCount = tmpInt
+			}
+
 			// configures used in privilege mode
 			if proxyClient.PrivilegeMode == true {
 				if PrivilegeToken == "" {
-					return fmt.Errorf("Parse conf error: proxy [%s] privilege_key must be set when privilege_mode = true", proxyClient.Name)
+					return fmt.Errorf("Parse conf error: proxy [%s] privilege_token must be set when privilege_mode = true", proxyClient.Name)
 				} else {
 					proxyClient.PrivilegeToken = PrivilegeToken
 				}

src/frp/models/config/config.go

@@ -22,4 +22,5 @@ type BaseConf struct {
 	UseGzip        bool
 	PrivilegeMode  bool
 	PrivilegeToken string
+	PoolCount      int64
 }

src/frp/models/metric/server.go

@@ -15,7 +15,6 @@
 package metric
 
 import (
-	"encoding/json"
 	"sort"
 	"sync"
 	"time"
@@ -64,15 +63,29 @@ func init() {
 	ServerMetricInfoMap = make(map[string]*ServerMetric)
 }
 
+func (s *ServerMetric) clone() *ServerMetric {
+	copy := *s
+	copy.CustomDomains = make([]string, len(s.CustomDomains))
+	var i int
+	for i = range copy.CustomDomains {
+		copy.CustomDomains[i] = s.CustomDomains[i]
+	}
+
+	copy.Daily = make([]*DailyServerStats, len(s.Daily))
+	for i = range copy.Daily {
+		tmpDaily := *s.Daily[i]
+		copy.Daily[i] = &tmpDaily
+	}
+	return &copy
+}
+
 func GetAllProxyMetrics() []*ServerMetric {
 	result := make(ServerMetricList, 0)
 	smMutex.RLock()
 	for _, metric := range ServerMetricInfoMap {
 		metric.mutex.RLock()
-		byteBuf, _ := json.Marshal(metric)
+		tmpMetric := metric.clone()
 		metric.mutex.RUnlock()
-		tmpMetric := &ServerMetric{}
-		json.Unmarshal(byteBuf, &tmpMetric)
 		result = append(result, tmpMetric)
 	}
 	smMutex.RUnlock()
@@ -88,9 +101,9 @@ func GetProxyMetrics(proxyName string) *ServerMetric {
 	defer smMutex.RUnlock()
 	metric, ok := ServerMetricInfoMap[proxyName]
 	if ok {
-		byteBuf, _ := json.Marshal(metric)
+		metric.mutex.RLock()
-		tmpMetric := &ServerMetric{}
+		tmpMetric := metric.clone()
-		json.Unmarshal(byteBuf, &tmpMetric)
+		metric.mutex.RUnlock()
 		return tmpMetric
 	} else {
 		return nil

src/frp/models/msg/msg.go

@@ -26,6 +26,7 @@ type ControlReq struct {
 	AuthKey       string `json:"auth_key"`
 	UseEncryption bool   `json:"use_encryption"`
 	UseGzip       bool   `json:"use_gzip"`
+	PoolCount     int64  `json:"pool_count"`
 
 	// configures used if privilege_mode is enabled
 	PrivilegeMode bool     `json:"privilege_mode"`

src/frp/models/server/config.go

@@ -42,6 +42,7 @@ var (
 	LogMaxDays       int64  = 3
 	PrivilegeMode    bool   = false
 	PrivilegeToken   string = ""
+	MaxPoolCount     int64  = 100
 	HeartBeatTimeout int64  = 90
 	UserConnTimeout  int64  = 10
 
@@ -155,6 +156,14 @@ func loadCommonConf(confFile string) error {
 			return fmt.Errorf("Parse conf error: privilege_token must be set if privilege_mode is enabled")
 		}
 	}
+
+	tmpStr, ok = conf.Get("common", "max_pool_count")
+	if ok {
+		v, err := strconv.ParseInt(tmpStr, 10, 64)
+		if err == nil && v >= 0 {
+			MaxPoolCount = v
+		}
+	}
 	return nil
 }
 

src/frp/models/server/server.go

@@ -43,7 +43,8 @@ type ProxyServer struct {
 	listeners    []Listener      // accept new connection from remote users
 	ctlMsgChan   chan int64      // every time accept a new user conn, put "1" to the channel
 	workConnChan chan *conn.Conn // get new work conns from control goroutine
-	mutex        sync.Mutex
+	mutex        sync.RWMutex
+	closeChan    chan struct{} // for notify other goroutines that the proxy is closed by close this channel
 }
 
 func NewProxyServer() (p *ProxyServer) {
@@ -71,9 +72,10 @@ func (p *ProxyServer) Init() {
 	p.Lock()
 	p.Status = consts.Idle
 	metric.SetStatus(p.Name, p.Status)
-	p.workConnChan = make(chan *conn.Conn, 100)
+	p.workConnChan = make(chan *conn.Conn, p.PoolCount+10)
-	p.ctlMsgChan = make(chan int64)
+	p.ctlMsgChan = make(chan int64, p.PoolCount+10)
 	p.listeners = make([]Listener, 0)
+	p.closeChan = make(chan struct{})
 	p.Unlock()
 }
 
@@ -134,6 +136,11 @@ func (p *ProxyServer) Start(c *conn.Conn) (err error) {
 	p.Unlock()
 	metric.SetStatus(p.Name, p.Status)
 
+	// create connection pool if needed
+	if p.PoolCount > 0 {
+		go p.connectionPoolManager(p.closeChan)
+	}
+
 	// start a goroutine for every listener to accept user connection
 	for _, listener := range p.listeners {
 		go func(l Listener) {
@@ -153,7 +160,7 @@ func (p *ProxyServer) Start(c *conn.Conn) (err error) {
 					return
 				}
 
-				// start another goroutine for join two conns from frpc and user
+				// start another goroutine for join two connections between frpc and user
 				go func() {
 					workConn, err := p.getWorkConn()
 					if err != nil {
@@ -161,14 +168,14 @@ func (p *ProxyServer) Start(c *conn.Conn) (err error) {
 					}
 
 					userConn := c
-					// msg will transfer to another without modifying
+					// message will be transferred to another without modifying
 					// l means local, r means remote
 					log.Debug("Join two connections, (l[%s] r[%s]) (l[%s] r[%s])", workConn.GetLocalAddr(), workConn.GetRemoteAddr(),
 						userConn.GetLocalAddr(), userConn.GetRemoteAddr())
 
+					metric.OpenConnection(p.Name)
 					needRecord := true
 					go msg.JoinMore(userConn, workConn, p.BaseConf, needRecord)
-					metric.OpenConnection(p.Name)
 				}()
 			}
 		}(listener)
@@ -187,6 +194,7 @@ func (p *ProxyServer) Close() {
 		}
 		close(p.ctlMsgChan)
 		close(p.workConnChan)
+		close(p.closeChan)
 		if p.CtlConn != nil {
 			p.CtlConn.Close()
 		}
@@ -210,7 +218,11 @@ func (p *ProxyServer) WaitUserConn() (closeFlag bool) {
 }
 
 func (p *ProxyServer) RegisterNewWorkConn(c *conn.Conn) {
-	p.workConnChan <- c
+	select {
+	case p.workConnChan <- c:
+	default:
+		log.Debug("ProxyName [%s], workConnChan is full, so close this work connection", p.Name)
+	}
 }
 
 // When frps get one user connection, we get one work connection from the pool and return it.
@@ -219,8 +231,8 @@ func (p *ProxyServer) RegisterNewWorkConn(c *conn.Conn) {
 // return an error if wait timeout
 func (p *ProxyServer) getWorkConn() (workConn *conn.Conn, err error) {
 	var ok bool
-
 	// get a work connection from the pool
+	for {
 		select {
 		case workConn, ok = <-p.workConnChan:
 			if !ok {
@@ -228,7 +240,7 @@ func (p *ProxyServer) getWorkConn() (workConn *conn.Conn, err error) {
 				return
 			}
 		default:
-		// no work connections available in the poll, send message to frpc to get one
+			// no work connections available in the poll, send message to frpc to get more
 			p.ctlMsgChan <- 1
 
 			select {
@@ -244,5 +256,47 @@ func (p *ProxyServer) getWorkConn() (workConn *conn.Conn, err error) {
 				return
 			}
 		}
+
+		// if connection pool is not used, we don't check the status
+		// function CheckClosed will consume at least 1 millisecond if the connection isn't closed
+		if p.PoolCount == 0 || !workConn.CheckClosed() {
+			break
+		} else {
+			log.Warn("ProxyName [%s], connection got from pool, but it's already closed", p.Name)
+		}
+	}
 	return
 }
+
+func (p *ProxyServer) connectionPoolManager(closeCh <-chan struct{}) {
+	for {
+		// check if we need more work connections and send messages to frpc to get more
+		time.Sleep(time.Duration(2) * time.Second)
+		select {
+		// if the channel closed, it means the proxy is closed, so just return
+		case <-closeCh:
+			log.Info("ProxyName [%s], connectionPoolManager exit", p.Name)
+			return
+		default:
+			curWorkConnNum := int64(len(p.workConnChan))
+			diff := p.PoolCount - curWorkConnNum
+			if diff > 0 {
+				if diff < p.PoolCount/5 {
+					diff = p.PoolCount*4/5 + 1
+				} else if diff < p.PoolCount/2 {
+					diff = p.PoolCount/4 + 1
+				} else if diff < p.PoolCount*4/5 {
+					diff = p.PoolCount/5 + 1
+				} else {
+					diff = p.PoolCount/10 + 1
+				}
+				if diff+curWorkConnNum > p.PoolCount {
+					diff = p.PoolCount - curWorkConnNum
+				}
+				for i := 0; i < int(diff); i++ {
+					p.ctlMsgChan <- 1
+				}
+			}
+		}
+	}
+}

src/frp/utils/conn/conn.go

@@ -145,8 +145,11 @@ func (c *Conn) Write(content string) (err error) {
 }
 
 func (c *Conn) SetDeadline(t time.Time) error {
-	err := c.TcpConn.SetDeadline(t)
+	return c.TcpConn.SetDeadline(t)
-	return err
+}
+
+func (c *Conn) SetReadDeadline(t time.Time) error {
+	return c.TcpConn.SetReadDeadline(t)
 }
 
 func (c *Conn) Close() {
@@ -160,7 +163,37 @@ func (c *Conn) Close() {
 
 func (c *Conn) IsClosed() (closeFlag bool) {
 	c.mutex.RLock()
+	defer c.mutex.RUnlock()
 	closeFlag = c.closeFlag
-	c.mutex.RUnlock()
 	return
 }
+
+// when you call this function, you should make sure that
+// remote client won't send any bytes to this socket
+func (c *Conn) CheckClosed() bool {
+	c.mutex.RLock()
+	if c.closeFlag {
+		return true
+	}
+	c.mutex.RUnlock()
+
+	// err := c.TcpConn.SetReadDeadline(time.Now().Add(100 * time.Microsecond))
+	err := c.TcpConn.SetReadDeadline(time.Now().Add(time.Millisecond))
+	if err != nil {
+		c.Close()
+		return true
+	}
+
+	var tmp []byte = make([]byte, 1)
+	_, err = c.TcpConn.Read(tmp)
+	if err == io.EOF {
+		return true
+	}
+
+	err = c.TcpConn.SetReadDeadline(time.Time{})
+	if err != nil {
+		c.Close()
+		return true
+	}
+	return false
+}