This commit implements an experimental UDP relay server. The UDP relay
server leverages the Disco protocol for a 3-way handshake between
client and server, along with 3 new Disco message types for said
handshake. These new Disco message types are also considered
experimental, and are not yet tied to a capver.
The server expects, and imposes, a Geneve (Generic Network
Virtualization Encapsulation) header immediately following the underlay
UDP header. Geneve protocol field values have been defined for Disco
and WireGuard. The Geneve control bit must be set for the handshake
between client and server, and unset for messages relayed between
clients through the server.
Updates tailscale/corp#27101
Signed-off-by: Jordan Whited <jordan@tailscale.com>
This adds the capability to pad disco ping message payloads to reach a
specified size. It also plumbs it through to the tailscale ping -size
flag.
Disco pings used for actual endpoint discovery do not use this yet.
Updates #311.
Signed-off-by: salman <salman@tailscale.com>
Co-authored-by: Val <valerie@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
This lets clients quickly (sub-millisecond within a local LAN) map
from an ambiguous disco key to a node key without waiting for a
CallMeMaybe (over relatively high latency DERP).
Updates #3088
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
