dhcpv6-pd: T2677: optimize CLI interface for PD configuration

The current CLI did not support multiple prefix-delegations per interface. Some
ISPs only send one /64 to a client per prefix-delegation request, but they
allow the customer to request multiple prefixes.

The 'dhcpv6-options prefix-delegation' node has been renamed and converted to a
tag node named 'dhcpv6-options pd'. The tag node specifies a PD request (>=0).

In the past the user needed to know what prefix will be assigned and required
to calculate the sla-len by himself. The 'sla-len' node was dropped and is now
calculated in the background from the 'dhcpv6-options pd 0 length' node.

It is no longer mandatory to supply the 'sla-id' node, if sla-id is not
specified it is 'guessed' by counting upwards.

Example configuration:
----------------------

  ethernet eth1 {
       address dhcpv6
       dhcpv6-options {
           pd 0 {
               length 56
               interface eth2 {
                   address 1
               }
           }
       }
   }

This will request a /56 assignment from the ISP and will delegate a /64 network
to interface eth2. VyOS will use the interface address ::1 on the delegate
interface (eth2) as its local address.

1 files changed, 1 insertions, 3 deletions

diff --git a/src/conf_mode/interfaces-pppoe.py b/src/conf_mode/interfaces-pppoe.py
index 928113b49..901ea769c 100755
--- a/src/conf_mode/interfaces-pppoe.py
+++ b/src/conf_mode/interfaces-pppoe.py
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import jmespath
 
 from sys import exit
 from copy import deepcopy
@@ -104,8 +103,7 @@ def generate(pppoe):
     render(script_pppoe_ipv6_up, 'pppoe/ipv6-up.script.tmpl',
            pppoe, trim_blocks=True, permission=0o755)
 
-    tmp = jmespath.search('dhcpv6_options.prefix_delegation.interface', pppoe)
-    if tmp and len(tmp) > 0:
+    if 'dhcpv6_options' in pppoe and 'pd' in pppoe['dhcpv6_options']:
         # ipv6.tmpl relies on ifname - this should be made consitent in the
         # future better then double key-ing the same value
         render(config_wide_dhcp6c, 'dhcp-client/ipv6.tmpl', pppoe, trim_blocks=True)