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vendor.github.com.pion.transport.vnet.net.go Maven / Gradle / Ivy
package vnet
import (
"encoding/binary"
"errors"
"fmt"
"math/rand"
"net"
"strconv"
"strings"
"sync"
)
const (
lo0String = "lo0String"
udpString = "udp"
)
var (
macAddrCounter uint64 = 0xBEEFED910200 //nolint:gochecknoglobals
errNoInterface = errors.New("no interface is available")
errNotFound = errors.New("not found")
errUnexpectedNetwork = errors.New("unexpected network")
errCantAssignRequestedAddr = errors.New("can't assign requested address")
errUnknownNetwork = errors.New("unknown network")
errNoRouterLinked = errors.New("no router linked")
errInvalidPortNumber = errors.New("invalid port number")
errUnexpectedTypeSwitchFailure = errors.New("unexpected type-switch failure")
errBindFailerFor = errors.New("bind failed for")
errEndPortLessThanStart = errors.New("end port is less than the start")
errPortSpaceExhausted = errors.New("port space exhausted")
errVNetDisabled = errors.New("vnet is not enabled")
)
func newMACAddress() net.HardwareAddr {
b := make([]byte, 8)
binary.BigEndian.PutUint64(b, macAddrCounter)
macAddrCounter++
return b[2:]
}
type vNet struct {
interfaces []*Interface // read-only
staticIPs []net.IP // read-only
router *Router // read-only
udpConns *udpConnMap // read-only
mutex sync.RWMutex
}
func (v *vNet) _getInterfaces() ([]*Interface, error) {
if len(v.interfaces) == 0 {
return nil, errNoInterface
}
return v.interfaces, nil
}
func (v *vNet) getInterfaces() ([]*Interface, error) {
v.mutex.RLock()
defer v.mutex.RUnlock()
return v._getInterfaces()
}
// caller must hold the mutex (read)
func (v *vNet) _getInterface(ifName string) (*Interface, error) {
ifs, err := v._getInterfaces()
if err != nil {
return nil, err
}
for _, ifc := range ifs {
if ifc.Name == ifName {
return ifc, nil
}
}
return nil, fmt.Errorf("interface %s %w", ifName, errNotFound)
}
func (v *vNet) getInterface(ifName string) (*Interface, error) {
v.mutex.RLock()
defer v.mutex.RUnlock()
return v._getInterface(ifName)
}
// caller must hold the mutex
func (v *vNet) getAllIPAddrs(ipv6 bool) []net.IP {
ips := []net.IP{}
for _, ifc := range v.interfaces {
addrs, err := ifc.Addrs()
if err != nil {
continue
}
for _, addr := range addrs {
var ip net.IP
if ipNet, ok := addr.(*net.IPNet); ok {
ip = ipNet.IP
} else if ipAddr, ok := addr.(*net.IPAddr); ok {
ip = ipAddr.IP
} else {
continue
}
if !ipv6 {
if ip.To4() != nil {
ips = append(ips, ip)
}
}
}
}
return ips
}
func (v *vNet) setRouter(r *Router) error {
v.mutex.Lock()
defer v.mutex.Unlock()
v.router = r
return nil
}
func (v *vNet) onInboundChunk(c Chunk) {
v.mutex.Lock()
defer v.mutex.Unlock()
if c.Network() == udpString {
if conn, ok := v.udpConns.find(c.DestinationAddr()); ok {
conn.onInboundChunk(c)
}
}
}
// caller must hold the mutex
func (v *vNet) _dialUDP(network string, locAddr, remAddr *net.UDPAddr) (UDPPacketConn, error) {
// validate network
if network != udpString && network != "udp4" {
return nil, fmt.Errorf("%w: %s", errUnexpectedNetwork, network)
}
if locAddr == nil {
locAddr = &net.UDPAddr{
IP: net.IPv4zero,
}
} else if locAddr.IP == nil {
locAddr.IP = net.IPv4zero
}
// validate address. do we have that address?
if !v.hasIPAddr(locAddr.IP) {
return nil, &net.OpError{
Op: "listen",
Net: network,
Addr: locAddr,
Err: fmt.Errorf("bind: %w", errCantAssignRequestedAddr),
}
}
if locAddr.Port == 0 {
// choose randomly from the range between 5000 and 5999
port, err := v.assignPort(locAddr.IP, 5000, 5999)
if err != nil {
return nil, &net.OpError{
Op: "listen",
Net: network,
Addr: locAddr,
Err: err,
}
}
locAddr.Port = port
} else if _, ok := v.udpConns.find(locAddr); ok {
return nil, &net.OpError{
Op: "listen",
Net: network,
Addr: locAddr,
Err: fmt.Errorf("bind: %w", errAddressAlreadyInUse),
}
}
conn, err := newUDPConn(locAddr, remAddr, v)
if err != nil {
return nil, err
}
err = v.udpConns.insert(conn)
if err != nil {
return nil, err
}
return conn, nil
}
func (v *vNet) listenPacket(network string, address string) (UDPPacketConn, error) {
v.mutex.Lock()
defer v.mutex.Unlock()
locAddr, err := v.resolveUDPAddr(network, address)
if err != nil {
return nil, err
}
return v._dialUDP(network, locAddr, nil)
}
func (v *vNet) listenUDP(network string, locAddr *net.UDPAddr) (UDPPacketConn, error) {
v.mutex.Lock()
defer v.mutex.Unlock()
return v._dialUDP(network, locAddr, nil)
}
func (v *vNet) dialUDP(network string, locAddr, remAddr *net.UDPAddr) (UDPPacketConn, error) {
v.mutex.Lock()
defer v.mutex.Unlock()
return v._dialUDP(network, locAddr, remAddr)
}
func (v *vNet) dial(network string, address string) (UDPPacketConn, error) {
v.mutex.Lock()
defer v.mutex.Unlock()
remAddr, err := v.resolveUDPAddr(network, address)
if err != nil {
return nil, err
}
// Determine source address
srcIP := v.determineSourceIP(nil, remAddr.IP)
locAddr := &net.UDPAddr{IP: srcIP, Port: 0}
return v._dialUDP(network, locAddr, remAddr)
}
func (v *vNet) resolveUDPAddr(network, address string) (*net.UDPAddr, error) {
if network != udpString && network != "udp4" {
return nil, fmt.Errorf("%w %s", errUnknownNetwork, network)
}
host, sPort, err := net.SplitHostPort(address)
if err != nil {
return nil, err
}
// Check if host is a domain name
ip := net.ParseIP(host)
if ip == nil {
host = strings.ToLower(host)
if host == "localhost" {
ip = net.IPv4(127, 0, 0, 1)
} else {
// host is a domain name. resolve IP address by the name
if v.router == nil {
return nil, errNoRouterLinked
}
ip, err = v.router.resolver.lookUp(host)
if err != nil {
return nil, err
}
}
}
port, err := strconv.Atoi(sPort)
if err != nil {
return nil, errInvalidPortNumber
}
udpAddr := &net.UDPAddr{
IP: ip,
Port: port,
}
return udpAddr, nil
}
func (v *vNet) write(c Chunk) error {
if c.Network() == udpString {
if udp, ok := c.(*chunkUDP); ok {
if c.getDestinationIP().IsLoopback() {
if conn, ok := v.udpConns.find(udp.DestinationAddr()); ok {
conn.onInboundChunk(udp)
}
return nil
}
} else {
return errUnexpectedTypeSwitchFailure
}
}
if v.router == nil {
return errNoRouterLinked
}
v.router.push(c)
return nil
}
func (v *vNet) onClosed(addr net.Addr) {
if addr.Network() == udpString {
//nolint:errcheck
v.udpConns.delete(addr) // #nosec
}
}
// This method determines the srcIP based on the dstIP when locIP
// is any IP address ("0.0.0.0" or "::"). If locIP is a non-any addr,
// this method simply returns locIP.
// caller must hold the mutex
func (v *vNet) determineSourceIP(locIP, dstIP net.IP) net.IP {
if locIP != nil && !locIP.IsUnspecified() {
return locIP
}
var srcIP net.IP
if dstIP.IsLoopback() {
srcIP = net.ParseIP("127.0.0.1")
} else {
ifc, err2 := v._getInterface("eth0")
if err2 != nil {
return nil
}
addrs, err2 := ifc.Addrs()
if err2 != nil {
return nil
}
if len(addrs) == 0 {
return nil
}
var findIPv4 bool
if locIP != nil {
findIPv4 = (locIP.To4() != nil)
} else {
findIPv4 = (dstIP.To4() != nil)
}
for _, addr := range addrs {
ip := addr.(*net.IPNet).IP
if findIPv4 {
if ip.To4() != nil {
srcIP = ip
break
}
} else {
if ip.To4() == nil {
srcIP = ip
break
}
}
}
}
return srcIP
}
// caller must hold the mutex
func (v *vNet) hasIPAddr(ip net.IP) bool { //nolint:gocognit
for _, ifc := range v.interfaces {
if addrs, err := ifc.Addrs(); err == nil {
for _, addr := range addrs {
var locIP net.IP
if ipNet, ok := addr.(*net.IPNet); ok {
locIP = ipNet.IP
} else if ipAddr, ok := addr.(*net.IPAddr); ok {
locIP = ipAddr.IP
} else {
continue
}
switch ip.String() {
case "0.0.0.0":
if locIP.To4() != nil {
return true
}
case "::":
if locIP.To4() == nil {
return true
}
default:
if locIP.Equal(ip) {
return true
}
}
}
}
}
return false
}
// caller must hold the mutex
func (v *vNet) allocateLocalAddr(ip net.IP, port int) error {
// gather local IP addresses to bind
var ips []net.IP
if ip.IsUnspecified() {
ips = v.getAllIPAddrs(ip.To4() == nil)
} else if v.hasIPAddr(ip) {
ips = []net.IP{ip}
}
if len(ips) == 0 {
return fmt.Errorf("%w %s", errBindFailerFor, ip.String())
}
// check if all these transport addresses are not in use
for _, ip2 := range ips {
addr := &net.UDPAddr{
IP: ip2,
Port: port,
}
if _, ok := v.udpConns.find(addr); ok {
return &net.OpError{
Op: "bind",
Net: udpString,
Addr: addr,
Err: fmt.Errorf("bind: %w", errAddressAlreadyInUse),
}
}
}
return nil
}
// caller must hold the mutex
func (v *vNet) assignPort(ip net.IP, start, end int) (int, error) {
// choose randomly from the range between start and end (inclusive)
if end < start {
return -1, errEndPortLessThanStart
}
space := end + 1 - start
offset := rand.Intn(space) //nolint:gosec
for i := 0; i < space; i++ {
port := ((offset + i) % space) + start
err := v.allocateLocalAddr(ip, port)
if err == nil {
return port, nil
}
}
return -1, errPortSpaceExhausted
}
// NetConfig is a bag of configuration parameters passed to NewNet().
type NetConfig struct {
// StaticIPs is an array of static IP addresses to be assigned for this Net.
// If no static IP address is given, the router will automatically assign
// an IP address.
StaticIPs []string
// StaticIP is deprecated. Use StaticIPs.
StaticIP string
}
// Net represents a local network stack euivalent to a set of layers from NIC
// up to the transport (UDP / TCP) layer.
type Net struct {
v *vNet
ifs []*Interface
}
// NewNet creates an instance of Net.
// If config is nil, the virtual network is disabled. (uses corresponding
// net.Xxxx() operations.
// By design, it always have lo0 and eth0 interfaces.
// The lo0 has the address 127.0.0.1 assigned by default.
// IP address for eth0 will be assigned when this Net is added to a router.
func NewNet(config *NetConfig) *Net {
if config == nil {
ifs := []*Interface{}
if orgIfs, err := net.Interfaces(); err == nil {
for _, orgIfc := range orgIfs {
ifc := NewInterface(orgIfc)
if addrs, err := orgIfc.Addrs(); err == nil {
for _, addr := range addrs {
ifc.AddAddr(addr)
}
}
ifs = append(ifs, ifc)
}
}
return &Net{ifs: ifs}
}
lo0 := NewInterface(net.Interface{
Index: 1,
MTU: 16384,
Name: lo0String,
HardwareAddr: nil,
Flags: net.FlagUp | net.FlagLoopback | net.FlagMulticast,
})
lo0.AddAddr(&net.IPNet{
IP: net.ParseIP("127.0.0.1"),
Mask: net.CIDRMask(8, 32),
})
eth0 := NewInterface(net.Interface{
Index: 2,
MTU: 1500,
Name: "eth0",
HardwareAddr: newMACAddress(),
Flags: net.FlagUp | net.FlagMulticast,
})
var staticIPs []net.IP
for _, ipStr := range config.StaticIPs {
if ip := net.ParseIP(ipStr); ip != nil {
staticIPs = append(staticIPs, ip)
}
}
if len(config.StaticIP) > 0 {
if ip := net.ParseIP(config.StaticIP); ip != nil {
staticIPs = append(staticIPs, ip)
}
}
v := &vNet{
interfaces: []*Interface{lo0, eth0},
staticIPs: staticIPs,
udpConns: newUDPConnMap(),
}
return &Net{
v: v,
}
}
// Interfaces returns a list of the system's network interfaces.
func (n *Net) Interfaces() ([]*Interface, error) {
if n.v == nil {
return n.ifs, nil
}
return n.v.getInterfaces()
}
// InterfaceByName returns the interface specified by name.
func (n *Net) InterfaceByName(name string) (*Interface, error) {
if n.v == nil {
for _, ifc := range n.ifs {
if ifc.Name == name {
return ifc, nil
}
}
return nil, fmt.Errorf("interface %s %w", name, errNotFound)
}
return n.v.getInterface(name)
}
// ListenPacket announces on the local network address.
func (n *Net) ListenPacket(network string, address string) (net.PacketConn, error) {
if n.v == nil {
return net.ListenPacket(network, address)
}
return n.v.listenPacket(network, address)
}
// ListenUDP acts like ListenPacket for UDP networks.
func (n *Net) ListenUDP(network string, locAddr *net.UDPAddr) (UDPPacketConn, error) {
if n.v == nil {
return net.ListenUDP(network, locAddr)
}
return n.v.listenUDP(network, locAddr)
}
// Dial connects to the address on the named network.
func (n *Net) Dial(network, address string) (net.Conn, error) {
if n.v == nil {
return net.Dial(network, address)
}
return n.v.dial(network, address)
}
// CreateDialer creates an instance of vnet.Dialer
func (n *Net) CreateDialer(dialer *net.Dialer) Dialer {
if n.v == nil {
return &vDialer{
dialer: dialer,
}
}
return &vDialer{
dialer: dialer,
v: n.v,
}
}
// DialUDP acts like Dial for UDP networks.
func (n *Net) DialUDP(network string, laddr, raddr *net.UDPAddr) (UDPPacketConn, error) {
if n.v == nil {
return net.DialUDP(network, laddr, raddr)
}
return n.v.dialUDP(network, laddr, raddr)
}
// ResolveUDPAddr returns an address of UDP end point.
func (n *Net) ResolveUDPAddr(network, address string) (*net.UDPAddr, error) {
if n.v == nil {
return net.ResolveUDPAddr(network, address)
}
return n.v.resolveUDPAddr(network, address)
}
func (n *Net) getInterface(ifName string) (*Interface, error) {
if n.v == nil {
return nil, errVNetDisabled
}
return n.v.getInterface(ifName)
}
func (n *Net) setRouter(r *Router) error {
if n.v == nil {
return errVNetDisabled
}
return n.v.setRouter(r)
}
func (n *Net) onInboundChunk(c Chunk) {
if n.v == nil {
return
}
n.v.onInboundChunk(c)
}
func (n *Net) getStaticIPs() []net.IP {
if n.v == nil {
return nil
}
return n.v.staticIPs
}
// IsVirtual tests if the virtual network is enabled.
func (n *Net) IsVirtual() bool {
return n.v != nil
}
// Dialer is identical to net.Dialer excepts that its methods
// (Dial, DialContext) are overridden to use virtual network.
// Use vnet.CreateDialer() to create an instance of this Dialer.
type Dialer interface {
Dial(network, address string) (net.Conn, error)
}
type vDialer struct {
dialer *net.Dialer
v *vNet
}
func (d *vDialer) Dial(network, address string) (net.Conn, error) {
if d.v == nil {
return d.dialer.Dial(network, address)
}
return d.v.dial(network, address)
}
