udhcpc: throttled down data transmission

[Laurent Bercot]

>I'm using 'udhcpc' on my ARM64 platform with the following scenario: I have one
>'eth0' interface that has a static ip address and the 'udhcpc' client on the
>same interface. That leads to low data transmission performace on that
>interface.

  Most people use udhcpc when they *don't* have a static IP address on
an interface, the point of DHCP being to assign an IP address. In that
common use case, it is impossible to use UDP, since IPv4 is not
configured yet! Listening on a raw socket is the only option.

  Your use case is pretty niche, already having IPv4 configured on your
interface before you use udhcpc. It's not surprising that udhcpc isn't
optimized for it: it's a small client after all.

  I suppose it could be patched to add an option to use UDP when the
interface already has an address, but it would mean effort, and more 
code
in busybox, which is probably not worth the trade-off.

--
  Laurent