maeqtt/main.go

package main

import (
	"log"
	"net"
	"runtime/debug"

	"badat.dev/maeqtt/v2/mqtt/packets"
	"badat.dev/maeqtt/v2/session"
)

func main() {
	listen_addr := ":1883"
	listener, err := net.Listen("tcp", listen_addr)

	if err != nil {
		log.Fatal(err)
	}

	var sessions map[string]*session.Session = make(map[string]*session.Session)

	for {
		conn, err := listener.Accept()
		if err != nil {
			log.Println("Failed accepting connection ", err)
		}
		handleConnection(conn, sessions)
	}
}

func handleConnection(con net.Conn, sessions map[string]*session.Session) {
	defer handlePanic(con)

	conReq, err := session.NewConnection(con)
	if err != nil {
		// TODO
		panic(err)
	}

	var sess *session.Session
	if conReq.ConnectPakcet.ClientId != nil {
		sess, exists := sessions[*conReq.ConnectPakcet.ClientId]
		if exists {
			sess.ConnecionChannel <- conReq
		}
	}

	if sess == nil {
		newSess := session.NewSession(conReq)
		sess = &newSess
		go func() {
			defer handlePanic(con)
			sess.HandlerLoop()
		}()
	}
}

func handlePanic(con net.Conn) {
	if r := recover(); r != nil {
		log.Println("Recovering from panic:", r)
		log.Println("Stack Trace:")
		debug.PrintStack()

		err := packets.DisconnectPacket{
			ReasonCode: packets.DisconnectReasonCodeImplErorr,
		}.Write(con)
		if err != nil {
			log.Println("Failed to send a disconnect packet after recovering from panic", err)
		}
	}
}