[pxe] Ensure cached DHCPACK is retrieved prior to network device creation
The retrieval of the cached DHCPACK and the creation of network
devices are both currently scheduled as STARTUP_NORMAL. It is
therefore possible that the cached DHCPACK will not be retrieved in
time for cachedhcp_probe() to apply it to the relevant network device.
Fix by retrieving the cached DHCPACK at initialisation time rather
than at startup time.
As an optimisation, an unclaimed cached DHCPACK can be freed
immediately after the last network device has been created, rather
than waiting until shutdown.
Reported-by: Espen Braastad <espen.braastad@redpill-linpro.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Most network upper-layer drivers do not implement all three methods
(probe, notify, and remove). Save code by making all methods
optional.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[pxe] Always retrieve cached DHCPACK and apply to relevant network device
When chainloading, always retrieve the cached DHCPACK packet from the
underlying PXE stack, and apply it as the original contents of the
"net<X>.dhcp" settings block. This allows cached DHCP settings to be
used for any chainloaded iPXE binary (not just undionly.kkpxe).
This change eliminates the undocumented "use-cached" setting. Issuing
the "dhcp" command will now always result in a fresh DHCP request.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown