EtherGuard-VPN/conn/conn.go

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/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
// Package conn implements WireGuard's network connections.
package conn
import (
"errors"
"net"
"strings"
)
// A Bind listens on a port for both IPv6 and IPv4 UDP traffic.
type Bind interface {
// LastMark reports the last mark set for this Bind.
LastMark() uint32
// SetMark sets the mark for each packet sent through this Bind.
// This mark is passed to the kernel as the socket option SO_MARK.
SetMark(mark uint32) error
// ReceiveIPv6 reads an IPv6 UDP packet into b.
//
// It reports the number of bytes read, n,
// the packet source address ep,
// and any error.
ReceiveIPv6(buff []byte) (n int, ep Endpoint, err error)
// ReceiveIPv4 reads an IPv4 UDP packet into b.
//
// It reports the number of bytes read, n,
// the packet source address ep,
// and any error.
ReceiveIPv4(b []byte) (n int, ep Endpoint, err error)
// Send writes a packet b to address ep.
Send(b []byte, ep Endpoint) error
// Close closes the Bind connection.
Close() error
}
// CreateBind creates a Bind bound to a port.
//
// The value actualPort reports the actual port number the Bind
// object gets bound to.
func CreateBind(port uint16) (b Bind, actualPort uint16, err error) {
return createBind(port)
}
// BindToInterface is implemented by Bind objects that support being
// tied to a single network interface.
type BindToInterface interface {
BindToInterface4(interfaceIndex uint32, blackhole bool) error
BindToInterface6(interfaceIndex uint32, blackhole bool) error
}
// An Endpoint maintains the source/destination caching for a peer.
//
// dst : the remote address of a peer ("endpoint" in uapi terminology)
// src : the local address from which datagrams originate going to the peer
type Endpoint interface {
ClearSrc() // clears the source address
SrcToString() string // returns the local source address (ip:port)
DstToString() string // returns the destination address (ip:port)
DstToBytes() []byte // used for mac2 cookie calculations
DstIP() net.IP
SrcIP() net.IP
}
func parseEndpoint(s string) (*net.UDPAddr, error) {
// ensure that the host is an IP address
host, _, err := net.SplitHostPort(s)
if err != nil {
return nil, err
}
if i := strings.LastIndexByte(host, '%'); i > 0 && strings.IndexByte(host, ':') >= 0 {
// Remove the scope, if any. ResolveUDPAddr below will use it, but here we're just
// trying to make sure with a small sanity test that this is a real IP address and
// not something that's likely to incur DNS lookups.
host = host[:i]
}
if ip := net.ParseIP(host); ip == nil {
return nil, errors.New("Failed to parse IP address: " + host)
}
// parse address and port
addr, err := net.ResolveUDPAddr("udp", s)
if err != nil {
return nil, err
}
ip4 := addr.IP.To4()
if ip4 != nil {
addr.IP = ip4
}
return addr, err
}