RE: [PATCH 00/13] drivers: hv: kvp

-----Original Message-----
From: Ben Hutchings [mailto:ben@decadent.org.uk]
Sent: Monday, July 02, 2012 3:57 PM
To: KY Srinivasan
Cc: Olaf Hering; Greg KH; apw@canonical.com; devel@linuxdriverproject.org;
virtualization@lists.osdl.org; linux-kernel@vger.kernel.org;
netdev@vger.kernel.org
Subject: Re: [PATCH 00/13] drivers: hv: kvp

On Mon, Jul 02, 2012 at 03:22:25PM +0000, KY Srinivasan wrote:

quoted

quoted

-----Original Message-----
From: Olaf Hering [mailto:olaf@aepfle.de]
Sent: Thursday, June 28, 2012 10:24 AM
To: KY Srinivasan
Cc: Greg KH; apw@canonical.com; devel@linuxdriverproject.org;
virtualization@lists.osdl.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/13] drivers: hv: kvp

On Tue, Jun 26, KY Srinivasan wrote:

quoted

quoted

From: Greg KH [mailto:gregkh@linuxfoundation.org]
The fact that it was Red Hat specific was the main part, this should be
done in a standard way, with standard tools, right?

The reason I asked this question was to make sure I address these
issues in addition to whatever I am debugging now. I use the standard
tools and calls to retrieve all the IP configuration. As I look at
each distribution the files they keep persistent IP configuration
Information is different and that is the reason I chose to start with
RedHat. If there is a standard way to store the configuration, I will
do that.

KY,

instead of using system() in kvp_get_ipconfig_info and kvp_set_ip_info,
wouldnt it be easier to call an external helper script which does all
the distribution specific work? Just define some API to pass values to
the script, and something to read values collected by the script back
into the daemon.

On the "Get" side I mostly use standard commands/APIs to get all the

information:

quoted

1) IP address information and subnet mask: getifaddrs()
2) DNS information:  Parsing /etc/resolv.conf
3) /sbin/ip command for all the routing information

If you're interested in the *current* configuration then (1) and (3)
are OK but you should really use the rtnetlink API.

However, I suspect that Hyper-V assumes that current and persistent
configuration are the same thing, which is obviously not true in
general on Linux.  But if NetworkManager is running then you can
assume they are.

I am only interested in the currently active information. Why do you
recommend the use of rtnetlink API over the "ip" command. If I am not
mistaken, the ip command uses netlink to get the information. 

quoted

4)  Parse /etc/sysconfig/network-scripts/ifcfg-ethx for boot protocol

This is the only information that requires parsing a distro specific configuration file. Do
you have any suggestion on how I may get this information in a distro independent way.
 

quoted

As you can see, all but the boot protocol is gathered using the "standard distro
independent mechanisms. I was looking at NetworkManager cli and it looks
like I could gather all the information except the boot protocol information. I am
not sure how to gather the boot protocol information in a distro independent

fashion.

quoted

On the SET side, I need to persistently store the settings in an appropriate

configuration

quoted

file and flush these settings down so that the interface is appropriately

configured. It is here

quoted

that I am struggling to find a distro independent way of doing things. It would

be great if I can

quoted

use NetworkManager cli (nmcli) to accomplish this. Any help here would be

greatly appreciated.
[...]

What was wrong with the NetworkManager D-Bus API I pointed you at?
I don't see how it makes sense to use nmcli as an API.

I saw some documentation that claimed that nmcli could be used to accomplish
all that can be done with the GUI interface. I am looking for a portable way
to accomplish configuring an interface. If nmcli can do that, I would use it. With
regards to D-BUS API, I took a cursory look at the APIs. I am still evaluating
my options.

Regards,

K. Y