ports

Documentation

Overview

Package ports provides PortManager that manages allocating, reserving and releasing ports.

Index

• Constants
• type PortManager
  • func NewPortManager() *PortManager
  • func (s *PortManager) IsPortAvailable(networks []tcpip.NetworkProtocolNumber, ...) bool
  • func (s *PortManager) PickEphemeralPort(testPort func(p uint16) (bool, *tcpip.Error)) (port uint16, err *tcpip.Error)
  • func (s *PortManager) PickEphemeralPortStable(offset uint32, testPort func(p uint16) (bool, *tcpip.Error)) (port uint16, err *tcpip.Error)
  • func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, ...)
  • func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, ...) (reservedPort uint16, err *tcpip.Error)

Constants

const (
	// FirstEphemeral is the first ephemeral port.
	FirstEphemeral = 16000
)

Types

type PortManager

type PortManager struct {
	// contains filtered or unexported fields
}

PortManager manages allocating, reserving and releasing ports.

func NewPortManager

func NewPortManager() *PortManager

NewPortManager creates new PortManager.

func (*PortManager) IsPortAvailable

func (s *PortManager) IsPortAvailable(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) bool

IsPortAvailable tests if the given port is available on all given protocols.

func (*PortManager) PickEphemeralPort

func (s *PortManager) PickEphemeralPort(testPort func(p uint16) (bool, *tcpip.Error)) (port uint16, err *tcpip.Error)

PickEphemeralPort randomly chooses a starting point and iterates over all possible ephemeral ports, allowing the caller to decide whether a given port is suitable for its needs, and stopping when a port is found or an error occurs.

func (*PortManager) PickEphemeralPortStable

func (s *PortManager) PickEphemeralPortStable(offset uint32, testPort func(p uint16) (bool, *tcpip.Error)) (port uint16, err *tcpip.Error)

PickEphemeralPortStable starts at the specified offset + s.portHint and iterates over all ephemeral ports, allowing the caller to decide whether a given port is suitable for its needs and stopping when a port is found or an error occurs.

func (*PortManager) ReleasePort

func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, bindToDevice tcpip.NICID)

ReleasePort releases the reservation on a port/IP combination so that it can be reserved by other endpoints.

func (*PortManager) ReservePort

func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) (reservedPort uint16, err *tcpip.Error)

ReservePort marks a port/IP combination as reserved so that it cannot be reserved by another endpoint. If port is zero, ReservePort will search for an unreserved ephemeral port and reserve it, returning its value in the "port" return value.