Fix app panic in multi-AS setup (#70)

* fixed panic for multi-AS setup

Author: chaehni

bwtester/bwtestserver/bwtestserver.go

@@ -115,11 +115,11 @@ func main() {
 	// Create the SCION UDP socket
 	if len(serverCCAddrStr) == 0 {
 		serverCCAddr, err = scionutil.GetLocalhost()
-		serverCCAddr.Host.L4 = addr.NewL4UDPInfo(uint16(serverPort))
 		if err != nil {
 			printUsage()
-			LogFatal("Unable to start server", "err", err)
+			LogFatal("Unable to start server, please provide the server address manually", "err", err)
 		}
+		serverCCAddr.Host.L4 = addr.NewL4UDPInfo(uint16(serverPort))
 	} else {
 		serverCCAddr, err = snet.AddrFromString(serverCCAddrStr)
 		if err != nil {

camerapp/imageserver/imageserver.go

@@ -155,8 +155,8 @@ func main() {
 		}
 	} else {
 		server, err = scionutil.GetLocalhost()
-		server.Host.L4 = addr.NewL4UDPInfo(uint16(serverPort))
 		check(err)
+		server.Host.L4 = addr.NewL4UDPInfo(uint16(serverPort))
 	}
 
 	if sciondFromIA {

roughtime/timeclient/main.go

@@ -42,12 +42,14 @@ func main() {
 
 	if *clientAddress != "" {
 		cAddr, err = scionutil.InitSCIONString(*clientAddress)
+		checkErr("InitSCIONString", err)
 	} else {
 		cAddr, err = scionutil.GetLocalhost()
+		checkErr("GetLocalhost", err)
 		cAddr.Host.L4 = addr.NewL4UDPInfo(0)
-		scionutil.InitSCION(cAddr)
+		err = scionutil.InitSCION(cAddr)
+		checkErr("InitSCION", err)
 	}
-	checkErr("Init SCION", err)
 
 	if cAddr.Host.L4.Port() != 0 {
 		log.Panicf("Application port must be set to 0, currently its %d", cAddr.Host.L4.Port())

sensorapp/sensorserver/sensorserver.go

@@ -116,8 +116,8 @@ func main() {
 		}
 	} else {
 		server, err = scionutil.GetLocalhost()
-		server.Host.L4 = addr.NewL4UDPInfo(uint16(serverPort))
 		check(err)
+		server.Host.L4 = addr.NewL4UDPInfo(uint16(serverPort))
 	}
 
 	if sciondFromIA {