tailscale/net/packet/ip.go

67 lines
1.8 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
// IPProto is an IP subprotocol as defined by the IANA protocol
// numbers list
// (https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml),
// or the special values Unknown or Fragment.
type IPProto uint8
const (
// Unknown represents an unknown or unsupported protocol; it's
// deliberately the zero value. Strictly speaking the zero
// value is IPv6 hop-by-hop extensions, but we don't support
// those, so this is still technically correct.
Unknown IPProto = 0x00
// Values from the IANA registry.
ICMPv4 IPProto = 0x01
IGMP IPProto = 0x02
ICMPv6 IPProto = 0x3a
TCP IPProto = 0x06
UDP IPProto = 0x11
// TSMP is the Tailscale Message Protocol (our ICMP-ish
// thing), an IP protocol used only between Tailscale nodes
// (still encrypted by WireGuard) that communicates why things
// failed, etc.
//
// Proto number 99 is reserved for "any private encryption
// scheme". We never accept these from the host OS stack nor
// send them to the host network stack. It's only used between
// nodes.
TSMP IPProto = 99
// Fragment represents any non-first IP fragment, for which we
// don't have the sub-protocol header (and therefore can't
// figure out what the sub-protocol is).
//
// 0xFF is reserved in the IANA registry, so we steal it for
// internal use.
Fragment IPProto = 0xFF
)
func (p IPProto) String() string {
switch p {
case Fragment:
return "Frag"
case ICMPv4:
return "ICMPv4"
case IGMP:
return "IGMP"
case ICMPv6:
return "ICMPv6"
case UDP:
return "UDP"
case TCP:
return "TCP"
case TSMP:
return "TSMP"
default:
return "Unknown"
}
}