tractor/examples/multihost/wg_lan/wg_maddr.py

64 lines
1.7 KiB
Python

# tractor: distributed structured concurrency.
r'''
Verify `wg` peers declared by tractor's multiaddr parser.
`tractor.discovery.parse_wg_maddr()` owns pure parsing and delegates
all tunnel peeling to `py-multiaddr`. This example keeps only the
explicit impure probe used by the two-host demo; parsing never shells
out or verifies local interface state implicitly.
The canonical maddr form is:
/ip4/10.0.0.1/udp/51820/wg/u<key>/ip4/10.0.11.1/tcp/1616
\_______ wg bearer ______/\_ key _/\____ tractor ep _____/
The kernel owns the bearer socket. A future tractor bindspace may
provision it through netlink, but only the overlay is an application
`MsgTransport` endpoint.
'''
from __future__ import annotations
import subprocess
from tractor.discovery import (
TunnelledAddress,
WGTunnelSpec,
)
def verify_wg_peer(
addr: TunnelledAddress,
iface: str|None = None,
) -> bool:
'''
Check the outer tunnel's key against one local `wg` iface.
IMPURE + explicit by design: neither `parse_wg_maddr()` nor
`tractor.discovery.parse_maddr()` calls this probe.
?TODO, per plan-03 layer B, swap this body for `pyroute2`
while retaining the explicit verification boundary.
'''
spec = addr.tunnel
if not isinstance(spec, WGTunnelSpec):
raise TypeError(
f'Unsupported tunnel spec: {type(spec)!r}'
)
iface = iface or spec.iface
def _wg(*args: str) -> str:
return subprocess.run(
['wg', 'show', iface, *args],
capture_output=True,
text=True,
check=True,
).stdout
return (
spec.peer_pubkey in _wg('peers').split()
or
spec.peer_pubkey == _wg('public-key').strip()
)