Make ssh_host_port_max an inclusive bound to agree with documentation

builder/qemu/step_forward_ssh.go

@@ -24,20 +24,12 @@ func (s *stepForwardSSH) Run(state multistep.StateBag) multistep.StepAction {
 
 	log.Printf("Looking for available SSH port between %d and %d", config.SSHHostPortMin, config.SSHHostPortMax)
 	var sshHostPort uint
-	var offset uint = 0
 
-	portRange := int(config.SSHHostPortMax - config.SSHHostPortMin)
+	portRange := config.SSHHostPortMax - config.SSHHostPortMin + 1
-	if portRange > 0 {
+	offset := uint(rand.Intn(int(portRange)))
-		// Have to check if > 0 to avoid a panic
-		offset = uint(rand.Intn(portRange))
-	}
 
 	for {
 		sshHostPort = offset + config.SSHHostPortMin
-		if sshHostPort >= config.SSHHostPortMax {
-			offset = 0
-			sshHostPort = config.SSHHostPortMin
-		}
 		log.Printf("Trying port: %d", sshHostPort)
 		l, err := net.Listen("tcp", fmt.Sprintf(":%d", sshHostPort))
 		if err == nil {
@@ -45,6 +37,9 @@ func (s *stepForwardSSH) Run(state multistep.StateBag) multistep.StepAction {
 			break
 		}
 		offset++
+		if offset == portRange {
+			offset = 0
+		}
 	}
 	ui.Say(fmt.Sprintf("Found port for SSH: %d.", sshHostPort))
 

builder/virtualbox/common/step_forward_ssh.go

@@ -37,20 +37,12 @@ func (s *StepForwardSSH) Run(state multistep.StateBag) multistep.StepAction {
 	if !s.SkipNatMapping {
 		log.Printf("Looking for available SSH port between %d and %d",
 			s.HostPortMin, s.HostPortMax)
-		offset := 0
 
-		portRange := int(s.HostPortMax - s.HostPortMin)
+		portRange := int(s.HostPortMax - s.HostPortMin + 1)
-		if portRange > 0 {
+		offset := rand.Intn(portRange)
-			// Have to check if > 0 to avoid a panic
-			offset = rand.Intn(portRange)
-		}
 
 		for {
 			sshHostPort = offset + int(s.HostPortMin)
-			if sshHostPort >= int(s.HostPortMax) {
-				offset = 0
-				sshHostPort = int(s.HostPortMin)
-			}
 			log.Printf("Trying port: %d", sshHostPort)
 			l, err := net.Listen("tcp", fmt.Sprintf("127.0.0.1:%d", sshHostPort))
 			if err == nil {
@@ -58,6 +50,9 @@ func (s *StepForwardSSH) Run(state multistep.StateBag) multistep.StepAction {
 				break
 			}
 			offset++
+			if offset == portRange {
+				offset = 0
+			}
 		}
 
 		// Create a forwarded port mapping to the VM