On Tue, Nov 22, 2016 at 08:21:12PM +0300, Andrei Borzenkov wrote: > 22.11.2016 01:02, Daniel Kiper ??????????: > > On Mon, Nov 21, 2016 at 10:52:24PM +0300, Andrei Borzenkov wrote: > >> 21.11.2016 16:09, Daniel Kiper ??????????: > >>> On Fri, Nov 18, 2016 at 09:11:47PM +0300, Andrei Borzenkov wrote: > >>>> 17.11.2016 22:02, Daniel Kiper ??????????: > >>>>> On Fri, Mar 18, 2016 at 08:42:00PM +0300, Andrei Borzenkov wrote: > >>>>>> Network boot autoconfiguration sets default server to next server IP > >>>>>> (siaddr) from BOOTP/DHCP reply, but manual configuration using > >>>>>> net_bootp > >>>>>> exports only server name. Unfortunately semantic of server name is not > >>>>>> clearly defined. BOOTP RFC 951 defines it only for client request, and > >>>>>> DHCP RFC 1541 only mentions it, without any implied usage. It looks > >>>>>> like > >>>>>> this field is mostly empty in server replies. > >>>>>> > >>>>>> Export next server IP as net_<interface>_server_ip variable. This > >>>>>> allows > >>>>>> grub configuration script to set $root/$prefix based on information > >>>>>> obtained > >>>>>> by net_bootp. > >>>>>> > >>>>>> Reported and tested by: Nikunj A Dadhania <nik...@linux.vnet.ibm.com> > >>>>>> Cc: nik...@linux.vnet.ibm.com > >>>>>> > >>>>>> --- > >>>>>> > >>>>>> @Nikunj: cosmetic changes comparing with version you tested - no need > >>>>>> to > >>>>>> allocate small buffer dynamically. > >>>>>> > >>>>>> @Vladimir: I think this is useful; I will update networking > >>>>>> documentation > >>>>>> in followup patch. > >>>>> > >>>>> Vladimir, Andrei, could you take care of it? > >>>>> > >>>>> Daniel > >>>>> > >>>> > >>>> I added documentation (not worth separate patch); if there are no > >>>> objections I commit. > >>>> > >>>> > >>>> From: Andrei Borzenkov <arvidj...@gmail.com> > >>>> Subject: [2.02][PATCH] bootp: export server IP as environment variable > >>>> > >>>> Network boot autoconfiguration sets default server to next server IP > >>>> (siaddr) from BOOTP/DHCP reply, but manual configuration using net_bootp > >>>> exports only server name. Unfortunately semantic of server name is not > >>>> clearly defined. BOOTP RFC 951 defines it only for client request, and > >>>> DHCP RFC 1541 only mentions it, without any implied usage. It looks like > >>>> this field is mostly empty in server replies. > >>>> > >>>> Export next server IP as net_<interface>_server_ip variable. This allows > >>>> grub configuration script to set $root/$prefix based on information > >>>> obtained > >>>> by net_bootp. > >>>> > >>>> Reported and tested by: Nikunj A Dadhania <nik...@linux.vnet.ibm.com> > >>>> Cc: nik...@linux.vnet.ibm.com > >>>> > >>>> --- > >>>> docs/grub.texi | 11 +++++++++++ > >>>> grub-core/net/bootp.c | 24 ++++++++++++++---------- > >>>> 2 files changed, 25 insertions(+), 10 deletions(-) > >>>> > >>>> diff --git a/docs/grub.texi b/docs/grub.texi > >>>> index 82f6fa4..bb03875 100644 > >>>> --- a/docs/grub.texi > >>>> +++ b/docs/grub.texi > >>>> @@ -2446,6 +2446,10 @@ The boot file name provided by DHCP. Read-only. > >>>> The name of the DHCP server responsible for these boot parameters. > >>>> Read-only. > >>>> > >>>> +@item net_@var{<interface>}_server_ip > >>>> +The IP address of the next (usually, TFTP) server provided by DHCP. > >>> > >>> BOOTP instead of DHCP? However, then we should change DHCP everywhere > >>> too... > >>> > >> > >> Yes. Sorry, it was probably my fault to refer to DHCP in the first place. > >> > >>>> +Read-only. > >>>> + > >>>> @item net_default_interface > >>>> Initially set to name of network interface that was used to load grub. > >>>> Read-write, although setting it affects only interpretation of > >>>> @@ -3062,6 +3066,7 @@ These variables have special meaning to GRUB. > >>>> * net_@var{<interface>}_hostname:: > >>>> * net_@var{<interface>}_ip:: > >>>> * net_@var{<interface>}_mac:: > >>>> +* net_@var{<interface>}_server_ip:: > >>> > >>> There is something known as net_default_server which contains next IP > >>> address. > >>> Should not we be more consistent and use "net_@var{<interface>}_server" > >>> instead > >>> of "net_@var{<interface>}_server_ip" here and there. > >>> > >> > >> Well, net_default_server is not really tied to any BOOTP/DHCP at all, > >> although it may be initially set based on content of ACK packet. I was > >> confused by dhcp_server_name, but they it is unrelated to next server. > >> > >> I'd rather used net_<interface>_next_server for clarity, both "server" > >> and "server_ip" are indeed too vague in this case. > > > > net_<interface>_next_server is OK for me. Should not we introduce > > net_default_next_server as RO then too? At first its value will be > > equal net_default_server but only net_default_server could be > > changed by user. Does it make sense? > > I would wait until someone has use case for it. I do not see it now.
OK, so, let's leave net_<interface>_next_server only right now. Thanks for committing this stuff. Daniel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel