blob: 4d5f5ae63afdf2ae53b3521071cbb14192b897dc [file] [log] [blame]
// Package nat is a convenience package for manipulation of strings describing network ports.
package nat
import (
"fmt"
"net"
"strconv"
"strings"
)
const (
// portSpecTemplate is the expected format for port specifications
portSpecTemplate = "ip:hostPort:containerPort"
)
// PortBinding represents a binding between a Host IP address and a Host Port
type PortBinding struct {
// HostIP is the host IP Address
HostIP string `json:"HostIp"`
// HostPort is the host port number
HostPort string
}
// PortMap is a collection of PortBinding indexed by Port
type PortMap map[Port][]PortBinding
// PortSet is a collection of structs indexed by Port
type PortSet map[Port]struct{}
// Port is a string containing port number and protocol in the format "80/tcp"
type Port string
// NewPort creates a new instance of a Port given a protocol and port number or port range
func NewPort(proto, port string) (Port, error) {
// Check for parsing issues on "port" now so we can avoid having
// to check it later on.
portStartInt, portEndInt, err := ParsePortRangeToInt(port)
if err != nil {
return "", err
}
if portStartInt == portEndInt {
return Port(fmt.Sprintf("%d/%s", portStartInt, proto)), nil
}
return Port(fmt.Sprintf("%d-%d/%s", portStartInt, portEndInt, proto)), nil
}
// ParsePort parses the port number string and returns an int
func ParsePort(rawPort string) (int, error) {
if len(rawPort) == 0 {
return 0, nil
}
port, err := strconv.ParseUint(rawPort, 10, 16)
if err != nil {
return 0, err
}
return int(port), nil
}
// ParsePortRangeToInt parses the port range string and returns start/end ints
func ParsePortRangeToInt(rawPort string) (int, int, error) {
if len(rawPort) == 0 {
return 0, 0, nil
}
start, end, err := ParsePortRange(rawPort)
if err != nil {
return 0, 0, err
}
return int(start), int(end), nil
}
// Proto returns the protocol of a Port
func (p Port) Proto() string {
proto, _ := SplitProtoPort(string(p))
return proto
}
// Port returns the port number of a Port
func (p Port) Port() string {
_, port := SplitProtoPort(string(p))
return port
}
// Int returns the port number of a Port as an int
func (p Port) Int() int {
portStr := p.Port()
// We don't need to check for an error because we're going to
// assume that any error would have been found, and reported, in NewPort()
port, _ := ParsePort(portStr)
return port
}
// Range returns the start/end port numbers of a Port range as ints
func (p Port) Range() (int, int, error) {
return ParsePortRangeToInt(p.Port())
}
// SplitProtoPort splits a port in the format of proto/port
func SplitProtoPort(rawPort string) (string, string) {
parts := strings.Split(rawPort, "/")
l := len(parts)
if len(rawPort) == 0 || l == 0 || len(parts[0]) == 0 {
return "", ""
}
if l == 1 {
return "tcp", rawPort
}
if len(parts[1]) == 0 {
return "tcp", parts[0]
}
return parts[1], parts[0]
}
func validateProto(proto string) bool {
for _, availableProto := range []string{"tcp", "udp"} {
if availableProto == proto {
return true
}
}
return false
}
// ParsePortSpecs receives port specs in the format of ip:public:private/proto and parses
// these in to the internal types
func ParsePortSpecs(ports []string) (map[Port]struct{}, map[Port][]PortBinding, error) {
var (
exposedPorts = make(map[Port]struct{}, len(ports))
bindings = make(map[Port][]PortBinding)
)
for _, rawPort := range ports {
portMappings, err := ParsePortSpec(rawPort)
if err != nil {
return nil, nil, err
}
for _, portMapping := range portMappings {
port := portMapping.Port
if _, exists := exposedPorts[port]; !exists {
exposedPorts[port] = struct{}{}
}
bslice, exists := bindings[port]
if !exists {
bslice = []PortBinding{}
}
bindings[port] = append(bslice, portMapping.Binding)
}
}
return exposedPorts, bindings, nil
}
// PortMapping is a data object mapping a Port to a PortBinding
type PortMapping struct {
Port Port
Binding PortBinding
}
func splitParts(rawport string) (string, string, string) {
parts := strings.Split(rawport, ":")
n := len(parts)
containerport := parts[n-1]
switch n {
case 1:
return "", "", containerport
case 2:
return "", parts[0], containerport
case 3:
return parts[0], parts[1], containerport
default:
return strings.Join(parts[:n-2], ":"), parts[n-2], containerport
}
}
// ParsePortSpec parses a port specification string into a slice of PortMappings
func ParsePortSpec(rawPort string) ([]PortMapping, error) {
var proto string
rawIP, hostPort, containerPort := splitParts(rawPort)
proto, containerPort = SplitProtoPort(containerPort)
// Strip [] from IPV6 addresses
ip, _, err := net.SplitHostPort(rawIP + ":")
if err != nil {
return nil, fmt.Errorf("Invalid ip address %v: %s", rawIP, err)
}
if ip != "" && net.ParseIP(ip) == nil {
return nil, fmt.Errorf("Invalid ip address: %s", ip)
}
if containerPort == "" {
return nil, fmt.Errorf("No port specified: %s<empty>", rawPort)
}
startPort, endPort, err := ParsePortRange(containerPort)
if err != nil {
return nil, fmt.Errorf("Invalid containerPort: %s", containerPort)
}
var startHostPort, endHostPort uint64 = 0, 0
if len(hostPort) > 0 {
startHostPort, endHostPort, err = ParsePortRange(hostPort)
if err != nil {
return nil, fmt.Errorf("Invalid hostPort: %s", hostPort)
}
}
if hostPort != "" && (endPort-startPort) != (endHostPort-startHostPort) {
// Allow host port range iff containerPort is not a range.
// In this case, use the host port range as the dynamic
// host port range to allocate into.
if endPort != startPort {
return nil, fmt.Errorf("Invalid ranges specified for container and host Ports: %s and %s", containerPort, hostPort)
}
}
if !validateProto(strings.ToLower(proto)) {
return nil, fmt.Errorf("Invalid proto: %s", proto)
}
ports := []PortMapping{}
for i := uint64(0); i <= (endPort - startPort); i++ {
containerPort = strconv.FormatUint(startPort+i, 10)
if len(hostPort) > 0 {
hostPort = strconv.FormatUint(startHostPort+i, 10)
}
// Set hostPort to a range only if there is a single container port
// and a dynamic host port.
if startPort == endPort && startHostPort != endHostPort {
hostPort = fmt.Sprintf("%s-%s", hostPort, strconv.FormatUint(endHostPort, 10))
}
port, err := NewPort(strings.ToLower(proto), containerPort)
if err != nil {
return nil, err
}
binding := PortBinding{
HostIP: ip,
HostPort: hostPort,
}
ports = append(ports, PortMapping{Port: port, Binding: binding})
}
return ports, nil
}