[BusyBox] Lease remembering in udhcpc?

[Josef Wolf]

Hello!

I have installed busybox with udhcpc, and it's working great that far.

There are just two things I am not entirely happy with:

1. When the dhcp server can't be reached, udhcpc disables the interface.
   I think it would be better to reuse the last ackquired lease as long
   as it is not expired.  Rfc2131 allows this behavior in section 3.2.3.

2. While default.script can be used to store the ackquired lease somewhere,
   there is no way to read and reuse this information at startup.

I would like to fix this, but I'm not entirely sure what would be the
best way.  My first approach would be:

- Every time a lease is received, write it into a cache file.
- When the server can't be reached, read in the cache file reuse the
  stored lease if it is still valid.
  
This would fix both cases above.

Opinions?

-- 
No software patents in Europe -- http://nosoftwarepatents.com
-- Josef Wolf -- jw at raven.inka.de --