Tools: hv: Gather DNS information

Now, gather DNS information. Invoke an external script (that can be
distro dependent) to gather the DNS information.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/hv/hv_kvp_daemon.c

@@ -549,6 +549,29 @@ static void kvp_get_ipconfig_info(char *if_name,
 	kvp_process_ipconfig_file(cmd, (char *)buffer->gate_way,
 				(MAX_GATEWAY_SIZE * 2), INET6_ADDRSTRLEN, 1);
 
+
+	/*
+	 * Gather the DNS  state.
+	 * Since there is no standard way to get this information
+	 * across various distributions of interest; we just invoke
+	 * an external script that needs to be ported across distros
+	 * of interest.
+	 *
+	 * Following is the expected format of the information from the script:
+	 *
+	 * ipaddr1 (nameserver1)
+	 * ipaddr2 (nameserver2)
+	 * .
+	 * .
+	 */
+
+	sprintf(cmd, "%s",  "hv_get_dns_info");
+
+	/*
+	 * Execute the command to gather DNS info.
+	 */
+	kvp_process_ipconfig_file(cmd, (char *)buffer->dns_addr,
+				(MAX_IP_ADDR_SIZE * 2), INET_ADDRSTRLEN, 0);
 }