Reworked event sendto to use connected UDP socket (cf. #9)

Makefile

@@ -82,7 +82,7 @@ publish: release
 	gh release create "$(VERSION)" "./dist/uhppote-simulator_$(VERSION).tar.gz"  "./dist/uhppote-simulator_$(VERSION).zip" --draft --prerelease --title "$(VERSION)-beta" --notes-file release-notes.md
 
 debug:
-	python3 cli.py list-controllers
+	curl -X POST "http://127.0.0.1:8765/uhppote/simulator/706050403/swipe" -H "accept: application/json" -H "Content-Type: application/json" -d '{"door":1, "card-number":10058400,"direction":1}'
 
 delve: build
 #	dlv test github.com/uhppoted/uhppote-simulator/simulator/UT0311L04 -- run TestCheckTimeProfileInTimeSegmentWithOffset

NOTES.md

@@ -11,3 +11,6 @@
    - 1999999 => 0x1E847F (stored as 0x0E847F)
    - probably just short-circuited byte-by-byte (nibble-by-nibble ?) equals
    - or maybe just masks out the most significant nibble ?
+
+2. https://blog.cloudflare.com/everything-you-ever-wanted-to-know-about-udp-sockets-but-were-afraid-to-ask-part-1/
+

TODO.md

@@ -1,23 +1,10 @@
 # TODO
 
-- [x] [Prebuilt Docker containers](https://github.com/uhppoted/uhppoted/issues/47)
-       - [x] Dockerfile
-       - [x] ghcr.io
-       - [x] compose.yml
-       - [x] README
-       - [x] CHANGELOG
-       - [x] _latest_
-       - [x] Update uhppote to use simulator docker
-
-- [x] [Startup fails with compressed controller](https://github.com/uhppoted/uhppote-simulator/issues/12)
-- [x] [`restore-default-parameters`](https://github.com/uhppoted/uhppoted/issues/48)
-- [x] [Document the HTTP requests](https://github.com/uhppoted/uhppote-simulator/issues/11)
-
 - [ ] https://github.com/uhppoted/uhppote-simulator/issues/9
       - Docker weirdness with events
       - Stops forwarding UDP event messages
       - https://stackoverflow.com/questions/54360408/docker-container-udp-communication-with-other-hosts
-      - https://serverfault.com/questions/866830/udp-traffic-not-forwarded-from-docker-containers-docker-host
+      - https://blog.cloudflare.com/everything-you-ever-wanted-to-know-about-udp-sockets-but-were-afraid-to-ask-part-1/
 
 ## TODO
 

commands/run.go

@@ -50,6 +50,12 @@ func Simulate(ctx *simulator.Context, dbg bool) {
 }
 
 func run(ctx *simulator.Context, connection *net.UDPConn, wait chan int) {
+	bind, err := net.ResolveUDPAddr("udp4", ctx.BindAddress)
+	if err != nil {
+		log.Errorf("failed to resolve UDP bind address [%v]", err)
+		return
+	}
+
 	go func() {
 		err := listenAndServe(ctx, connection)
 		if err != nil {
@@ -61,7 +67,12 @@ func run(ctx *simulator.Context, connection *net.UDPConn, wait chan int) {
 	go func() {
 		for {
 			msg := ctx.DeviceList.GetMessage()
-			send(connection, msg.Destination, msg.Message)
+
+			if msg.Event {
+				sendto(bind, msg.Destination, msg.Message)
+			} else {
+				send(connection, msg.Destination, msg.Message)
+			}
 		}
 	}()
 
@@ -132,21 +143,52 @@ func receive(c *net.UDPConn) ([]byte, *net.UDPAddr, error) {
 	return request[:N], remote, nil
 }
 
-func send(c *net.UDPConn, dest *net.UDPAddr, message interface{}) {
+func send(c *net.UDPConn, dest *net.UDPAddr, message any) {
 	msg, err := codec.Marshal(message)
 	if err != nil {
 		log.Errorf("%v", err)
 		return
 	}
 
-	N, err := c.WriteTo(msg, dest)
+	N, err := c.WriteToUDP(msg, dest)
 	if err != nil {
 		log.Errorf("failed to write to UDP socket [%v]", err)
 	} else if debug {
 		log.Infof("sent %v bytes to %v\n%s", N, dest, dump(msg[0:N], " ...          "))
 	}
 }
 
+func sendto(bind *net.UDPAddr, dest *net.UDPAddr, message any) {
+	var addr *net.UDPAddr
+
+	if bind != nil && bind.IP != nil {
+		addr = &net.UDPAddr{
+			IP:   bind.IP.To4(),
+			Port: 0,
+			Zone: bind.Zone,
+		}
+	}
+
+	msg, err := codec.Marshal(message)
+	if err != nil {
+		log.Errorf("%v", err)
+		return
+	}
+
+	if c, err := net.DialUDP("udp4", addr, dest); err != nil {
+		log.Errorf("failed to create UDP event socket [%v]", err)
+	} else {
+		defer c.Close()
+
+		N, err := c.Write(msg)
+		if err != nil {
+			log.Errorf("failed to write to UDP socket [%v]", err)
+		} else if debug {
+			log.Infof("sent %v bytes to %v\n%s", N, dest, dump(msg[0:N], " ...          "))
+		}
+	}
+}
+
 func dump(m []byte, prefix string) string {
 	return regexp.MustCompile("(?m)^(.*)").ReplaceAllString(hex.Dump(m), prefix+"$1")
 }

entities/message.go

@@ -7,4 +7,5 @@ import (
 type Message struct {
 	Destination *net.UDPAddr
 	Message     interface{}
+	Event       bool
 }

simulator/UT0311L04/UTC0311L04.go

@@ -344,7 +344,7 @@ func (s *UT0311L04) Delete() error {
 	return nil
 }
 
-func (s *UT0311L04) send(dest *net.UDPAddr, message interface{}) {
+func (s *UT0311L04) send(dest *net.UDPAddr, message any) {
 	if s.txq == nil {
 		panic(fmt.Sprintf("Device %d: missing TXQ", s.SerialNumber))
 	}
@@ -353,6 +353,21 @@ func (s *UT0311L04) send(dest *net.UDPAddr, message interface{}) {
 		s.txq <- entities.Message{
 			Destination: dest,
 			Message:     message,
+			Event:       false,
+		}
+	}
+}
+
+func (s *UT0311L04) sendto(dest *net.UDPAddr, message any) {
+	if s.txq == nil {
+		panic(fmt.Sprintf("Device %d: missing TXQ", s.SerialNumber))
+	}
+
+	if s.txq != nil && dest != nil && message != nil && !reflect.ValueOf(message).IsNil() {
+		s.txq <- entities.Message{
+			Destination: dest,
+			Message:     message,
+			Event:       true,
 		}
 	}
 }
@@ -423,14 +438,15 @@ func (s *UT0311L04) add(event entities.Event) {
 		Direction:  event.Direction,
 	}
 
+	// ... firmware 6.62 had a slightly different format
 	if fmt.Sprintf("%v", s.Version) == "6.62" {
 		e662 := messages.EventV6_62{
 			Event: e,
 		}
 
-		s.send(s.Listener, &e662)
+		s.sendto(s.Listener, &e662)
 	} else {
-		s.send(s.Listener, &e)
+		s.sendto(s.Listener, &e)
 	}
 }