Hi Doug,

Thanks. However, what you mentioned is not in the proxy mode. Have you successfully enable the proxy (relay) mode and it works for uEFI network booting?

Thanks.

Steven


On 3/30/2017 PM 12:13, Doug Brown wrote:
Hi Steven,

If I find some free time, I might try tracing through the code to figure
out why dnsmasq is throwing out the DHCP packets on port 4011 in the EFI
+ PXE configuration without a proxy. In the meantime, here is the
configuration that works for me with dhcp-boot (assuming my dnsmasq
server's IP address is 192.168.1.1):

port=0
log-dhcp
enable-tftp
tftp-root=/tftpboot
dhcp-no-override
dhcp-vendorclass=BIOS,PXEClient:Arch:00000
dhcp-vendorclass=UEFI,PXEClient:Arch:00007
dhcp-vendorclass=UEFI64,PXEClient:Arch:00009
dhcp-boot=pxelinux.0,,192.168.1.1
dhcp-boot=net:UEFI,shim.efi,,192.168.1.1
dhcp-boot=net:UEFI64,shim.efi,,192.168.1.1
dhcp-range=ens33,192.168.1.50,192.168.1.99,10h

In this example, I'm using shim-signed (named as shim.efi) and
grubnetx64.efi.signed (named as grubx64.efi) from Ubuntu, and it should
properly boot a UEFI computer even if it has Secure Boot enabled. Shim
downloads grubx64.efi, which then downloads grub.cfg.

Hope this helps!
Doug


On 3/28/2017 11:46 PM, Steven Shiau wrote:
Hi Doug,

Thanks for your explanation. Simon also emailed me after my post and
let me know where the problem is. The conclusion is this issue seems
not be easily fixed.
So the patch for grub will be applied after grub 2.02. Before that,
could you please show me the configuration file you confirmed it will
work by using dhcp-boot strategy?
Thank you very much.

Steven


On 3/27/2017 AM 11:29, Doug Brown wrote:
Hi Simon and Steven,

I just found this recent thread while I was Googling for the exact
same problem (UEFI clients won't boot in PXE mode, but BIOS clients
will) and there was never any conclusion reached. I'm running into
the exact same problem, and I can provide a pcap dump, which I have
attached to this message. After the initial DHCP exchange, it shows
four DHCP packets on port 4011 sent from the client which seem to be
ignored by dnsmasq. Here is the configuration I am using with dnsmasq
2.76, based on Steven's original third example:

port=0
log-dhcp
dhcp-no-override
enable-tftp
tftp-root=/tftpboot
dhcp-range=ens33,192.168.7.100,192.168.7.200,10h
pxe-service=X86PC, "Boot BIOS PXE", pxelinux.0
pxe-service=BC_EFI, "Boot UEFI BC", grubx64.efi
pxe-service=X86-64_EFI, "Boot UEFI X86-64", grubx64.efi

If I switch to using the dhcp-boot strategy, everything works great
on both BIOS and UEFI. But the above configuration using PXE doesn't
seem to work properly with UEFI clients for some reason, and it seems
to be a dnsmasq issue. It does work fine with BIOS clients though.

I think I can answer Steven's earlier question as to why proxy PXE
(example config #4) doesn't work with UEFI. The problem in that case
is not due to dnsmasq at all -- it's correctly sending grub to the
client. The problem is that grub doesn't know how to detect that it
was loaded from a DHCP proxy, so it won't know where to download
grub.cfg. Shim, which you can use as a first stage bootloader to load
grub if you need to support Secure Boot, has the exact same problem.
It only knows how to look at the original DHCP ack's boot info. The
UEFI environment provides info about the proxy offer, but grub and
shim don't look at it. See the following thread where a patch was
submitted for grub:

https://lists.gnu.org/archive/html/grub-devel/2016-04/msg00051.html

I think it's probably possible to work around the proxy problem by
using grub-mkstandalone to create a version of grub.efi that has an
embedded intermediate grub.cfg that is coded to download the real
grub.cfg from your server, as long as you don't need Secure Boot
support.

Either way, I still think there's something wrong with dnsmasq's PXE
support because the example config above (non-proxy) doesn't work
with any UEFI clients that I have tested, as shown by the pcap dump
attached. Any ideas?

Thanks,
Doug

On 1/26/2017 11:16 AM, Simon Kelley wrote:
There's no DHCP traffic in that capture. It appears to all be ssh.

Wrong interface?


Cheers,

Simon.


On 24/01/17 08:50, Steven Shiau wrote:
Hi Simon,
Attached please find the dump file of the command "tcpdump -s 0 -w
capturefile". Let me know if you need more info. Thank you very
much.
Steven

On 1/24/2017 AM 05:25, Simon Kelley wrote: Thanks for the reply.
Please could you repeat the tcpdump using the command
tcpdump -s 0 -w capturefile
and send me the resulting file? That has far more information than
tcpdump prints.

Cheers,
Simon.
On 20/01/17 08:39, Steven Shiau wrote:
Hi Simon,

Thanks for your reply. I am answering you in the following.

On 2017/01/20 06:47, Simon Kelley wrote:
Your example 3 - I'm confused why that shouldn't work - the
PXE client seems to be making further requests which are
bring ignored. Would it be possible for you to get a packet
dump of that exchange using tcpdump?
$ sudo tcpdump -ni ens38 'udp port 67 and udp port 68'
tcpdump: verbose output suppressed, use -v or -vv for full
protocol decode listening on ens38, link-type EN10MB
(Ethernet), capture size 262144 bytes 16:18:33.208355 IP
0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from
00:0c:29:1d:9a:d1, length 347 16:18:36.205647 IP
192.168.22.254.67 > 255.255.255.255.68: BOOTP/DHCP, Reply,
length 341 16:18:36.385548 IP 0.0.0.0.68 >
255.255.255.255.67: BOOTP/DHCP, Request from
00:0c:29:1d:9a:d1, length 359 16:18:36.386212 IP
192.168.22.254.67 > 255.255.255.255.68: BOOTP/DHCP, Reply,
length 341 ^C 4 packets captured 4 packets received by filter
0 packets dropped by kernel

Example 4 looks quite hopeful - the client is
succerssfully downloading the bootx64.efi file (ignore the
error before, that's just testing for the existance of the
file.

Can you see what's displayed on the client system at this
point?
It's blank screen due to the background_image for grub is
not downloaded,  and in the end the grub shows no grub.cfg
error, as attached. That format is from the grub prefix we
added by: ======================================= set
prefix=(tftp)/grub-efi.cfg echo "Grub CPU and platform:
\$grub_cpu, \$grub_platform" echo 'Network status: '
net_ls_cards net_ls_addr net_ls_routes

tr --set pretty_mac x: x- \$net_default_mac

echo "Loading config file
\$prefix/grub.cfg-01-\$pretty_mac..." configfile
\$prefix/grub.cfg-01-\$pretty_mac

echo "Loading config file
\$prefix/grub.cfg-\$net_default_ip..." configfile
\$prefix/grub.cfg-\$net_default_ip

echo "Loading config file: \$prefix/grub.cfg" configfile
\$prefix/grub.cfg

echo "Could not find config file
\$prefix/grub.cfg-\$pretty_mac,
\$prefix/grub.cfg-\$net_default_ip or \$prefix/grub.cfg!"
sleep 15 ======================================= This is
exactly the same problem as mentioned here:

http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2016q4/010
931

.html
i.e., only grub efi is downloaded, while the rest of required files
are
not downloaded. As I mentioned for comparison, for non-proxy
mode with same configuration, it works well.

Thanks again.

Steven



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