caa82f2861
When using IP aliases on loopback (e.g. ip addr add 10.1.1.1/32 dev lo) with policy routing, findInterfaceByIP() resolves the alias IP to the loopback interface. Binding the socket to lo via SO_BINDTODEVICE prevents outbound traffic from reaching non-local destinations. Skip SO_BINDTODEVICE when the resolved interface is loopback — source IP binding via LocalAddr is sufficient for policy routing to steer traffic through the correct physical interface.