RE: [PATCH] tools: hv: kvp_daemon: make IPv6-only-injection work

[Dexuan Cui]

> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx]
> Sent: Tuesday, December 9, 2014 21:06 PM
> To: Dexuan Cui
> Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; driverdev-
> devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx;
> jasowang@xxxxxxxxxx; KY Srinivasan; Haiyang Zhang
> Subject: Re: [PATCH] tools: hv: kvp_daemon: make IPv6-only-injection work
>  ......
> > +	 * Here "dhcp_enabled" is only for IPv4 according to Hyper-V host
> team.
> > +	 *
> > +	 * In the case the host only injects 1 IPv6 address:
> > +	 * new_val->dhcp_enabled is true, but we can't pass
> BOOTPROTO=dhcp to
> > +	 * the script hv_set_ifconfig, because in some distros (like RHEL7)
> > +	 * BOOTPROTO=dhcp has a special meaning in the config file (e.g.,
> > +	 * /etc/sysconfig/network-scripts/ifcfg-eth0): the network init
> program
> > +	 * ignores any static IP addr information once there is
> > +	 * BOOTPROTO=dhcp; as a result, IPv6-only injection can't work.
> > +	 *
> > +	 * In the case of IPv6-only injection, BOOTPROTO=dhcp doesn't affect
> > +	 * Ubuntu because it's ignored by the Ubuntu version of
> > +	 * hv_set_ifconfig and it doesn't seem to have special meaning in
> > +	 * Ubuntu.
> > +	 */
> 
> I just checked and adding "IPV6ADDR=something" when "BOOTPROTO=dhcp"
> works for me with both RHEL7 and Fedora21.
It doesn't work in my side. :-(
Running 'ifup eth0' shows some errors(I use "set -x")
...
+ /sbin/dhclient -H localhost -1 -q -lf /var/lib/dhclient/dhclient--eth0.lease -pf /var/run/dhclient-eth0.pid eth0
grep: /etc/sysconfig/network-scripts/ifcfg-eth0: Permission dinied.
grep: /etc/sysconfig/network-scripts/ifcfg-eth0: Permission dinied.
grep: /etc/sysconfig/network-scripts/ifcfg-eth0: Permission dinied.
grep: /etc/sysconfig/network-scripts/ifcfg-eth0: Permission dinied.
grep: /etc/sysconfig/network-scripts/ifcfg-eth0: Permission dinied.
grep: /etc/sysconfig/network-scripts/ifcfg-eth0: Permission dinied.
done.

I'm trying to find out the cause.

> Other than that I think bringing distribution specifics into kernel.git
> is not a good idea. /etc/sysconfig/network-scripts/ifcfg-* format is
> distro-specific and not all Linux distros support it. Moreover,
I agree.

> different distros can treat setting differently. I think it was wrong to
> stick to this format in kvp daemon from very beginning.
We can also think the current format used in kvp daemon is already
distro-agnostic -- it just happens to look like the style of network config file
used in RHEL :-)

> 
> As a solution I would suggest doing the following: kvp daemon writes all
> received request details in distro-agnostic format in some temporary
> place and then calls distro-specific script to set things up. Actually,
> we already have such script: tools/hv/hv_set_ifconfig.sh
Yeah, this is exactly what we already have today.

> As for this bug I propose the following: remove skipping all
> IPADDR/MASK/... settings in case of "BOOTPROTO=dhcp" and let
> distro-specific script deal with the rest.
> --
>   Vitaly
OK, so the patch would be 1-line only:

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 22b0764..53fdaad 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -1314,10 +1314,8 @@ static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val)
                        goto setval_error;

                /*
-                * We are done!.
+                * We are not done... TODO: add comment here.
                 */
-               goto setval_done;
-
        } else {
                error = kvp_write_file(file, "BOOTPROTO", "", "none");
                if (error)

I'll send out a v2 after I resolve the "grep ... Permission dinied" issue.

Thanks,
-- Dexuan
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