[lwip-users] DHCP bug fixed, but one subtle additional bug found

[Leon Woestenberg]

Hello,

I just fixed a bug in DHCP where its DECLINE messages were
useless to the server. This would only occur on networks where the
DHCP server is not aware of manually assigned IP addresses
(which it normally is aware of through ARP queries).

(Bug fix is only in "DEVEL" CVS branch at this time).

In tracing the bug, we came across a situation where the second
attempt to obtain a lease (after first declining an address that was
already in use with another host) would actually be accepted
by the lwIP client, although it was offered the *very same*
address still in use by the other host.

lwIP DHCP did not seem to perform the ARP check against
the offered address the second time.

I am still investigating this one.

Regards,

Leon.