The AddSNATRuleForDst rule was adding a new rule each time it was called including:
- if a rule already existed
- if a rule matching the destination, but with different desired source already existed
This was causing issues especially for the in-progress egress HA proxies work,
where the rules are now refreshed more frequently, so more redundant rules
were being created.
This change:
- only creates the rule if it doesn't already exist
- if a rule for the same dst, but different source is found, delete it
- also ensures that egress proxies refresh firewall rules
if the node's tailnet IP changes
Updates tailscale/tailscale#13406
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
9bd158cc09