package server import ( "context" "fmt" "io" "sync" "time" "github.com/gorilla/websocket" "git.coolaj86.com/coolaj86/go-telebitd/rvpn/packer" ) // Connection track websocket and faciliates in and out data type Connection struct { mutex sync.Mutex // The main connection table (should be just one of these created at startup) connectionTable *Table //used to track traffic for a domain. Not use for lookup or validation only for tracking DomainTrack map[string]*DomainTrack // The websocket connection. conn *websocket.Conn // Buffered channel of outbound messages. send chan *SendTrack // WssState channel // Must check state via channel before xmit // Address of the Remote End Point source string // serverName -- Name of the server, at this point 1st domain registered. Will likely change with JWT serverName string // bytes in bytesIn int64 // bytes out bytesOut int64 // requests requests int64 // response responses int64 // Connect Time connectTime time.Time //lastUpdate lastUpdate time.Time //initialDomains - a list of domains from the JWT initialDomains []interface{} connectionTrack *Tracking ///wssState tracks a highlevel status of the connection, false means do nothing. wssState bool //connectionID connectionID int64 } //NewConnection -- Constructor func NewConnection(connectionTable *Table, conn *websocket.Conn, remoteAddress string, initialDomains []interface{}, connectionTrack *Tracking, serverName string) (p *Connection) { connectionID = connectionID + 1 p = new(Connection) p.connectionTable = connectionTable p.conn = conn p.source = remoteAddress p.serverName = serverName p.bytesIn = 0 p.bytesOut = 0 p.requests = 0 p.responses = 0 p.send = make(chan *SendTrack) p.connectTime = time.Now() p.initialDomains = initialDomains p.connectionTrack = connectionTrack p.DomainTrack = make(map[string]*DomainTrack) p.lastUpdate = time.Now() for _, domain := range initialDomains { p.AddTrackedDomain(string(domain.(string))) } p.SetState(true) p.connectionID = connectionID return } //AddTrackedDomain -- Add a tracked domain func (c *Connection) AddTrackedDomain(domain string) { p := new(DomainTrack) p.DomainName = domain c.DomainTrack[domain] = p } //ServerName -- Property func (c *Connection) ServerName() string { return c.serverName } //SetServerName -- Setter func (c *Connection) SetServerName(serverName string) { c.serverName = serverName } //InitialDomains -- Property func (c *Connection) InitialDomains() []interface{} { return c.initialDomains } //ConnectTime -- Property func (c *Connection) ConnectTime() time.Time { return c.connectTime } //BytesIn -- Property func (c *Connection) BytesIn() int64 { return c.bytesIn } //BytesOut -- Property func (c *Connection) BytesOut() int64 { return c.bytesOut } //SendCh -- property to sending channel func (c *Connection) SendCh() chan *SendTrack { return c.send } //Source -- func (c *Connection) Source() string { return c.source } func (c *Connection) addIn(num int64) { c.bytesIn = c.bytesIn + num } func (c *Connection) addOut(num int64) { c.bytesOut = c.bytesOut + num } func (c *Connection) addRequests() { c.requests = c.requests + 1 } func (c *Connection) addResponse() { c.responses = c.responses + 1 } //ConnectionTable -- property func (c *Connection) ConnectionTable() *Table { return c.connectionTable } //State -- Get state of Socket...this is a high level state. func (c *Connection) State() bool { c.mutex.Lock() defer c.mutex.Unlock() return c.wssState } //SetState -- Set the set of the high level connection func (c *Connection) SetState(state bool) { c.mutex.Lock() defer c.mutex.Unlock() c.wssState = state } //Update -- updates the lastUpdate property tracking idle time func (c *Connection) Update() { c.mutex.Lock() defer c.mutex.Unlock() c.lastUpdate = time.Now() } //LastUpdate -- retrieve last update func (c *Connection) LastUpdate() time.Time { return c.lastUpdate } //ConnectionID - Get func (c *Connection) ConnectionID() int64 { return c.connectionID } //NextWriter -- Wrapper to allow a high level state check before offering NextWriter //The libary failes if client abends during write-cycle. a fast moving write is not caught before socket state bubbles up //A synchronised state is maintained func (c *Connection) NextWriter(wssMessageType int) (io.WriteCloser, error) { if c.State() { return c.conn.NextWriter(wssMessageType) } // Is returning a nil error actually the proper thing to do here? loginfo.Println("NextWriter aborted, state is not true") return nil, nil } //Write -- Wrapper to allow a high level state check before allowing a write to the socket. func (c *Connection) Write(w io.WriteCloser, message []byte) (int, error) { if c.State() { return w.Write(message) } // Is returning a nil error actually the proper thing to do here? return 0, nil } //Reader -- export the reader function func (c *Connection) Reader(ctx context.Context) { connectionTrack := c.connectionTrack defer func() { c.connectionTable.unregister <- c c.conn.Close() loginfo.Println("reader defer", c) }() loginfo.Println("Reader Start ", c) //c.conn.SetReadLimit(65535) for { _, message, err := c.conn.ReadMessage() //loginfo.Println("ReadMessage", msgType, err) c.Update() if err != nil { if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway) { c.SetState(false) loginfo.Printf("error: %v", err) } break } // unpack the message. p, err := packer.ReadMessage(message) key := fmt.Sprintf("%s:%d", p.Address(), p.Port()) track, err := connectionTrack.Lookup(key) //loginfo.Println(hex.Dump(p.Data.Data())) if err != nil { //loginfo.Println("Unable to locate Tracking for ", key) continue } //Support for tracking outbound traffic based on domain. if domainTrack, ok := c.DomainTrack[track.domain]; ok { //if ok then add to structure, else warn there is something wrong domainTrack.AddOut(int64(len(message))) domainTrack.AddResponses() } track.conn.Write(p.Data.Data()) c.addIn(int64(len(message))) c.addResponse() //loginfo.Println("end of read") } } //Writer -- expoer the writer function func (c *Connection) Writer() { defer c.conn.Close() loginfo.Println("Writer Start ", c) for { select { case message := <-c.send: w, err := c.NextWriter(websocket.BinaryMessage) loginfo.Println("next writer ", w) if err != nil { c.SetState(false) return } c.Update() _, err = c.Write(w, message.data) if err := w.Close(); err != nil { return } messageLen := int64(len(message.data)) c.addOut(messageLen) c.addRequests() //Support for tracking outbound traffic based on domain. if domainTrack, ok := c.DomainTrack[message.domain]; ok { //if ok then add to structure, else warn there is something wrong domainTrack.AddIn(messageLen) domainTrack.AddRequests() loginfo.Println("adding ", messageLen, " to ", message.domain) } else { logdebug.Println("attempting to add bytes to ", message.domain, "it does not exist") logdebug.Println(c.DomainTrack) } loginfo.Println(c) } } }