net/interfaces, net/netns: add node attributes to control default interface getting and binding

With #6566 we started to more aggressively bind to the default interface
on Darwin. We are seeing some reports of the wrong cellular interface
being chosen on iOS. To help with the investigation, this adds to knobs
to control the behavior changes:
- CapabilityDebugDisableAlternateDefaultRouteInterface disables the
  alternate function that we use to get the default interface on macOS
  and iOS (implemented in tailscale/corp#8201). We still log what it
  would have returned so we can see if it gets things wrong.
- CapabilityDebugDisableBindConnToInterface is a bigger hammer that
  disables binding of connections to the default interface altogether.

Updates #7184
Updates #7188

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This commit is contained in:
Mihai Parparita
2023-02-08 10:30:06 -08:00
committed by Mihai Parparita
parent fb84ccd82d
commit 62f4df3257
6 changed files with 50 additions and 1 deletions

View File

@@ -1765,6 +1765,17 @@ const (
// details on the behaviour of this capability.
CapabilityBindToInterfaceByRoute = "https://tailscale.com/cap/bind-to-interface-by-route"
// CapabilityDebugDisableAlternateDefaultRouteInterface changes how Darwin
// nodes get the default interface. There is an optional hook (used by the
// macOS and iOS clients) to override the default interface, this capability
// disables that and uses the default behavior (of parsing the routing
// table).
CapabilityDebugDisableAlternateDefaultRouteInterface = "https://tailscale.com/cap/debug-disable-alternate-default-route-interface"
// CapabilityDebugDisableBindConnToInterface disables the automatic binding
// of connections to the default network interface on Darwin nodes.
CapabilityDebugDisableBindConnToInterface = "https://tailscale.com/cap/debug-disable-bind-conn-to-interface"
// CapabilityTailnetLockAlpha indicates the node is in the tailnet lock alpha,
// and initialization of tailnet lock may proceed.
//