[U-Boot] DHCP regression on 2009-06

[Robin Getz]

http://git.denx.de/?p=u-boot/u-boot-net.git;a=commitdiff;h=3c172c4fdbbb5858fae38478d6399be4a16be3fc

causes a regression on my network's DHCP server.

The part of the diff that causes the problem:

 #if defined(CONFIG_CMD_DHCP)

                case DHCP:
-                       /* Start with a clean slate... */
                        BootpTry = 0;
-                       NetOurIP = 0;
-                       NetServerIP = getenv_IPaddr ("serverip");
                        DhcpRequest();          /* Basically same as BOOTP */
                        break;

Since we are leaving the "NetOurIP" to whatever it was... The test at:
NetReceive():

         case PROT_IP:
            [snip]
                tmp = NetReadIP(&ip->ip_dst);
                if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
#ifdef CONFIG_MCAST_TFTP
                        if (Mcast_addr != tmp)
#endif
                        return;
                }

Will return - (we leave the 'NetOurIP' set to the old value, the offered 
address (what is in tmp) is not our's and tmp is not 0xFFFFFFFF).

You never process the DHCP_OFFER...

There are multiple ways of fixing things - setting "NetOurIP = 0;" (revert one 
line of the change, which may expose the bug that Michael was trying to fix), 
or try to be more tricky in the "not our address" check....