wwan: T9388: apply a static bearer's address/gateway/DNS directly

QMI raw-ip modems get their address, gateway and DNS from ModemManager
as a "static" bearer instead of over a DHCP(v6) or Router Advertisement
exchange, so "address dhcp", "address dhcpv6" and "ipv6 address
autoconf" never produced a usable config and only worked for IPv4 by
accident.

Check the interface's connected bearer first. If its method for the
family is static, apply it directly; if it is dhcp, or there is no
bearer yet, fall through to the existing DHCP(v6) client / kernel SLAAC
unchanged.

- Address and DNS are applied from the bearer. DNS is registered with
  vyos-hostsd under the same dhcp-<if>/dhcpv6-<if> tags a real client
  uses. A DHCP(v6) client which was started while the bearer was still
  missing, including one which keeps restarting, is stopped before the
  settings are applied.
- The default route is rendered into FRR as a tag 210 static route, the
  same way a DHCP one is. WWANIf records the gateway of the bearer in
  /run/vyos-wwan, which the new get_wwan_router() filter reads, and a
  new block in staticd.frr.j2 fed by get_wwan_interfaces() renders the
  IPv4 and IPv6 default routes. Distance, no-default-route and VRFs
  behave as for DHCP, also for an interface without "address dhcp".
  frrender notices a gateway change, and WWANIf reconciles FRR with
  vyos-frr-render.py whenever the recorded gateway changes, the way the
  dhclient lease hook does, so op-mode reconnect is covered as well.
  The state is written atomically, as the renderer reads it
  concurrently.
- The address installed from the bearer is recorded in /run/vyos-wwan
  too. It is removed on reconnect, when the family is no longer
  configured and when the interface goes away, and nothing else on the
  interface is ever touched.
- vyos-netlinkd applies the bearer again after it re-dials a lost
  session, as the new session can come back with a different address or
  gateway. A DHCP client used to pick that up on its own. What a
  previous session left behind is dropped for a family the new one does
  not supply, the configured DHCP(v6) client or SLAAC is started for it
  as a commit would, and an incomplete result is retried on the
  following reconcile passes for a while.
- The bearer is picked by its connected status rather than bearers[0],
  and its config is polled briefly with wait_for() until it is no
  longer missing or a placeholder, since it can be populated slightly
  after the bearer reports connected.

0 files changed, 0 insertions, 0 deletions