[U-Boot-Users] [PATCH] DHCP Client Fix

[Ben Warren]

Wolfgang Denk wrote:
> Dear Justin,
>
> in message <4155D0DA4B6B044891B3F19311C7E7B89C45E4 at EXCHANGE1.886llc.local> you wrote:
>   
>> I recently upgraded the firmware on some of my old Linksys WRT54G
>> routers (version 5) from firmware version 1.0.6 to firmware version
>> 1.02.2, both of which are released by Linksys and U-Boot was no longer
>> able to get an IP address using DHCP.  However, with the older firmware
>> (version 1.0.6), U-Boot was still able to get an IP through DHCP.
>>
>> Using a hub and a packet sniffer, I was able to locate the problem.  The
>> U-Boot code will bind to an IP address offered by the DHCP server
>> prematurely and the DHCP server will not respond with an ACK, rendering
>>     
>
> I have to admit that I'm not sure if this is a bug in  U-Boot  or  in
> the  Linksys  router  (which I have under special observation as they
> explicitely and intentionally violate the U-Boot GPL).
>
>   
>> the system without an IP address.  This is no longer valid when using a
>> Linksys router as DHCP server.  I modified the code to operate the way
>> the Linux DHCP client does by not binding to the offered IP until the
>> DHCP client receives the ACK sent by the server, ending the
>> conversation.  After making the appropriate changes, DCHP service was
>> restored for all flavors of the Linksys firmware that I have available
>> (v 1.02.2 and v1.0.6 for the version 5 router, v8.00.2 for the version 8
>> router).  It has also been tested on an AirPort Extreme router running
>> DHCP.
>>
>> Attached is the patch with the code changes that were made. Any feed
>> back would be appreciated.
>>     
>
> I'm waiting for feedback (or a pull request?) from the network
> custodian.
>
> Ben???
>
>   
This looks promising.  I'll provide feedback after doing some testing 
tomorrow.

regards,
Ben