add peer discovery

main.go

@@ -58,7 +58,7 @@ func main() {
 		},
 	}
 	app.Flags = []cli.Flag{
-		cli.StringFlag{Name: "relay", Value: "ws://localhost:8152"},
+		cli.StringFlag{Name: "relay", Value: "ws://croc4.schollz.com"},
 		cli.BoolFlag{Name: "no-local", Usage: "disable local mode"},
 		cli.BoolFlag{Name: "local", Usage: "use only local mode"},
 		cli.BoolFlag{Name: "debug", Usage: "increase verbosity (a lot)"},

src/croc/sending.go

@@ -1,6 +1,7 @@
 package croc
 
 import (
+	"fmt"
 	"os"
 	"os/signal"
 	"time"
@@ -10,36 +11,125 @@ import (
 	"github.com/schollz/croc/src/recipient"
 	"github.com/schollz/croc/src/relay"
 	"github.com/schollz/croc/src/sender"
+	"github.com/schollz/peerdiscovery"
 )
 
 // Send the file
 func (c *Croc) Send(fname, codephrase string) (err error) {
 	log.Debugf("sending %s", fname)
-	return c.sendReceive(fname, codephrase, true)
+	errChan := make(chan error)
+
+	// normally attempt two connections
+	waitingFor := 2
+
+	// use public relay
+	if !c.LocalOnly {
+		go func() {
+			// atttempt to connect to public relay
+			errChan <- c.sendReceive(c.WebsocketAddress, fname, codephrase, true)
+		}()
+	} else {
+		waitingFor = 1
+	}
+
+	// use local relay
+	if !c.NoLocal {
+		go func() {
+			// start own relay and connect to it
+			go relay.Run(c.ServerPort)
+			time.Sleep(250 * time.Millisecond) // race condition here, but this should work most of the time :(
+
+			// broadcast for peer discovery
+			go func() {
+				log.Debug("listening for local croc relay...")
+				go peerdiscovery.Discover(peerdiscovery.Settings{
+					Limit:     1,
+					TimeLimit: 600 * time.Second,
+					Delay:     50 * time.Millisecond,
+					Payload:   []byte(c.ServerPort),
+				})
+			}()
+
+			// connect to own relay
+			errChan <- c.sendReceive("ws://localhost:"+c.ServerPort, fname, codephrase, true)
+		}()
+	} else {
+		waitingFor = 1
+	}
+
+	err = <-errChan
+	if err == nil || waitingFor == 1 {
+		return
+	}
+	log.Debug(err)
+	return <-errChan
 }
 
 // Receive the file
 func (c *Croc) Receive(codephrase string) (err error) {
-	return c.sendReceive("", codephrase, false)
+	log.Debug("receiving")
+	waitingFor := 2
+	errChan := make(chan error)
+
+	// use public relay
+	if !c.LocalOnly {
+		go func() {
+			// atttempt to connect to public relay
+			errChan <- c.sendReceive(c.WebsocketAddress, "", codephrase, false)
+		}()
+	} else {
+		waitingFor = 1
+	}
+
+	// use local relay
+	if !c.NoLocal {
+		go func() {
+			// try to discovery codephrase and server through peer network
+			discovered, errDiscover := peerdiscovery.Discover(peerdiscovery.Settings{
+				Limit:     1,
+				TimeLimit: 300 * time.Millisecond,
+				Delay:     50 * time.Millisecond,
+				Payload:   []byte("checking"),
+			})
+			if errDiscover != nil {
+				log.Debug(errDiscover)
+			}
+			if len(discovered) > 0 {
+				log.Debugf("discovered %s on %s", discovered[0].Payload, discovered[0].Address)
+				errChan <- c.sendReceive(fmt.Sprintf("ws://%s:%s", discovered[0].Address, discovered[0].Payload), "", codephrase, false)
+			} else {
+				log.Debug("discovered no peers")
+				waitingFor = 1
+			}
+		}()
+	} else {
+		waitingFor = 1
+	}
+
+	err = <-errChan
+	if err == nil || waitingFor == 1 {
+		return
+	}
+	log.Debug(err)
+	return <-errChan
 }
 
-func (c *Croc) sendReceive(fname, codephrase string, isSender bool) (err error) {
+func (c *Croc) sendReceive(websocketAddress, fname, codephrase string, isSender bool) (err error) {
 	defer log.Flush()
 
 	// allow interrupts
 	interrupt := make(chan os.Signal, 1)
 	signal.Notify(interrupt, os.Interrupt)
 
+	done := make(chan struct{})
 	// connect to server
-	log.Debugf("connecting to %s", c.WebsocketAddress)
-	sock, _, err := websocket.DefaultDialer.Dial(c.WebsocketAddress+"/ws", nil)
+	log.Debugf("connecting to %s", websocketAddress)
+	sock, _, err := websocket.DefaultDialer.Dial(websocketAddress+"/ws", nil)
 	if err != nil {
 		return
 	}
 	defer sock.Close()
 
-	done := make(chan struct{})
-
 	// tell the websockets we are connected
 	err = sock.WriteMessage(websocket.BinaryMessage, []byte("connected"))
 	if err != nil {
@@ -47,6 +137,7 @@ func (c *Croc) sendReceive(fname, codephrase string, isSender bool) (err error)
 	}
 
 	if isSender {
+		// start peerdiscovery relay server
 		go sender.Send(done, sock, fname, codephrase)
 	} else {
 		go recipient.Receive(done, sock, codephrase)