Re: Grub Not Routing TFTP Appropriately

[Travis DePrato]

Yes - I just built grub-2.02 from ftp://ftp.gnu.org/gnu/grub/ and can
confirm that it's doing the same thing (sending packets to the wrong
ethernet address).

I'm not sure what you mean by a packet trace from the port grub is
connected to. I've placed wireshark between the client and the wall. The
conversation looks roughly like this:

DHCP DISCOVER/REQUEST/ACKNOWLEDGE
Client ARP's for TFTP server
Client sends TFTP RRQ for pxe/grub/x86_64-efi/core.efi (to router's mac
address and TFTP server's IP address)
[ Lots of Blocks Transferred ]
Client ARP's for router
Client sends TFTP RRQ for pxe/grub/x86_64-efi/normal.mod (to router's mac
address and TFTP server's IP address)
TFTP server doesn't get it, client continues trying to send RRQ for
normal.mod

On Tue, May 16, 2017 at 12:49 PM Andrei Borzenkov <address@hidden>
wrote:

> 16.05.2017 18:23, Travis DePrato пишет:
> > grub2-efi-2.02-0.29, taken from RHEL 7.2 installation media rpm.
> >
>
> Can you reproduce it with plain upstream version? It is hard to tell
> what upstream it corresponds exactly.
>
> There was similar bug that was fixed relatively long ago. If you can
> reproduce it with upstream, could you provide packet trace, if possible
> from the port grub is connected to?
>
> > On Mon, May 15, 2017 at 11:17 PM Andrei Borzenkov <address@hidden>
> > wrote:
> >
> >> 15.05.2017 22:37, Travis DePrato пишет:
> >>> Hello, all!
> >>>
> >>> I've been attempting to get UEFI Network booting working for a while
> now
> >>> (compounded by many unrelated issues) but I've run into one that I
> >> believe
> >>> to be definitely the fault of GRUB (perhaps this should be a bug
> report?
> >>> I'm not sure).
> >>>
> >>> I've been using various grubx64.efi/bootx64.efi/core.efi images. Each
> >>> machine seems to have the same issue: the uefi network rom loads the
> grub
> >>> efi image appropriately, then when it tries to load grub.cfg (for
> >>> grubx64.efi) or the other components (starting with normal.mod), it
> >> routes
> >>> the packets incorrectly.
> >>>
> >>> For the initial .efi image, it communicates directly with the TFTP
> server
> >>> on the ethernet layer (i.e. packets are routed directly to the mac
> >> address
> >>> of the TFTP server) whereas when grub continues trying to load
> >> components,
> >>> it tries to route through the router/gateway (it first arp's for the IP
> >> of
> >>> the gateway sends packets to the ethernet address of the gateway), and
> >>> those packets are summarily dropped (I've confirmed that the TFTP
> server
> >>> doesn't get them via wireshark).
> >>>
> >>> Ideas?
> >>>
> >>
> >> What is your grub version?
> >>
>
> --
Travis DePrato (he/him/his)
University of Michigan, Ann Arbor
Computer Science & Engineering
Mathematics (Discrete and Algorithmic Methods)
Computer Consultant at EECS DCO