pfSense

Add ovpn qinqs to bridges instead of rebuilding them. Fixes #13666

qinq interfaces defined with parent openvpn interfaces are configured late in
rc.bootup, after qinqs for other physical and logical interfaces and bridges are
configured. The resolution to #13225 ensured that these late interfaces were
added to bridges by calling interfaces_bridge_configure() to reconfigure all
bridges interfaces but this had the inadvertent effect of removing all IP
configuration from bridge interfaces, which must be restored via
interface_configure(). This measure was also overly aggressive in destroying all
bridges when few or no openvpn qinqs exist. Since interface_configure() is never
called for these interfaces, they also lack a description at the OS level.

This change:

• Alters the behavior of openvpn_resync_all() to cycle through all configured
  openvpn interfaces, calling interface_configure() on them.

• Alters the behavior of interface_configure() to always call
  interface_bridge_add_member() for openvpn and ipsec interfaces, not just
  after platform booting is complete.

• Alters the behavior of interface_bridge_add_member() to reconfigure either
  the bridge or member interface to the lower of their respective MTUs. gif
  interface MTUs associated with a bridge MTU <= 1500 are not reconfigured
  according to prior precendent.