Tools: hv: Add an example script to retrieve dhcp state

To keep the KVP daemon code free of distro specific details, we invoke an
external script to retrieve the DHCP state. This is an example script that
was used to test the KVP code. This script has to be implemented in a Distro
specific fashion. For instance on distros that ship with Network Manager enabled,
this script can be based on NM APIs.

Signed-off-by: K. Y. Srinivasan <[e-mail]>
Reviewed-by: Haiyang Zhang <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

tools/hv/hv_get_dhcp_info.sh

···
+#!/bin/bash
+
+# This example script retrieves the DHCP state of a given interface.
+# In the interest of keeping the KVP daemon code free of distro specific
+# information; the kvp daemon code invokes this external script to gather
+# DHCP setting for the specific interface.
+#
+# Input: Name of the interface
+#
+# Output: The script prints the string "Enabled" to stdout to indicate
+#	that DHCP is enabled on the interface. If DHCP is not enabled,
+#	the script prints the string "Disabled" to stdout.
+#
+# Each Distro is expected to implement this script in a distro specific
+# fashion. For instance on Distros that ship with Network Manager enabled,
+# this script can be based on the Network Manager APIs for retrieving DHCP
+# information.
+
+if_file="/etc/sysconfig/network-scripts/ifcfg-"$1
+
+dhcp=$(grep "dhcp" $if_file 2>/dev/null)
+
+if [ "$dhcp" != "" ];
+then
+echo "Enabled"
+else
+echo "Disabled"
+fi