cloudflared-mirror/ingress/origin_icmp_proxy.go

54 lines
1.2 KiB
Go

package ingress
import (
"context"
"fmt"
"net/netip"
"time"
"github.com/rs/zerolog"
"golang.org/x/net/icmp"
"github.com/cloudflare/cloudflared/packet"
)
const (
defaultCloseAfterIdle = time.Second * 15
mtu = 1500
icmpTimeoutMs = 1000
)
var (
errFlowInactive = fmt.Errorf("flow is inactive")
errPacketNil = fmt.Errorf("packet is nil")
)
// ICMPProxy sends ICMP messages and listens for their responses
type ICMPProxy interface {
// Serve starts listening for responses to the requests until context is done
Serve(ctx context.Context) error
// Request sends an ICMP message
Request(pk *packet.ICMP, responder packet.FlowResponder) error
}
func NewICMPProxy(listenIP netip.Addr, logger *zerolog.Logger) (ICMPProxy, error) {
return newICMPProxy(listenIP, logger)
}
// Opens a non-privileged ICMP socket on Linux and Darwin
func newICMPConn(listenIP netip.Addr) (*icmp.PacketConn, error) {
network := "udp6"
if listenIP.Is4() {
network = "udp4"
}
return icmp.ListenPacket(network, listenIP.String())
}
func getICMPEcho(pk *packet.ICMP) (*icmp.Echo, error) {
echo, ok := pk.Message.Body.(*icmp.Echo)
if !ok {
return nil, fmt.Errorf("expect ICMP echo, got %s", pk.Type)
}
return echo, nil
}