dhcpv6-pd: T2506: add option to request specific prefix length

Some ISPs (e.g. Comcast) only delegate a /64 by default. You have to explicitly
"ask" for a bigger (e.g. /60) prefix. This commit adds a CLI node to request
a specific prefix length in the range 32 - 64.

  dhcpv6-options {
      prefix-delegation {
          length 60
      }
  }

9 files changed, 28 insertions, 0 deletions

diff --git a/data/templates/dhcp-client/ipv6.tmpl b/data/templates/dhcp-client/ipv6.tmpl
index 8957516e2..490f14726 100644
--- a/data/templates/dhcp-client/ipv6.tmpl
+++ b/data/templates/dhcp-client/ipv6.tmpl
@@ -23,6 +23,9 @@ id-assoc na 1 {
 
 {%  if dhcpv6_pd_interfaces %}
 id-assoc pd 2 {
+{%  if dhcpv6_pd_length %}
+    prefix ::/{{ dhcpv6_pd_length }} infinity;
+{%  endif %}
 {%  for intf in dhcpv6_pd_interfaces %}
     prefix-interface {{ intf.ifname }} {
 {%    if intf.sla_id %}
diff --git a/python/vyos/configdict.py b/python/vyos/configdict.py
index 6afc78039..3e1f22d09 100644
--- a/python/vyos/configdict.py
+++ b/python/vyos/configdict.py
@@ -112,6 +112,7 @@ interface_default_data = {
     'dhcp_vendor_class_id': '',
     'dhcpv6_prm_only': False,
     'dhcpv6_temporary': False,
+    'dhcpv6_pd_length': '',
     'dhcpv6_pd_interfaces': [],
     'disable': False,
     'disable_link_detect': 1,
diff --git a/python/vyos/ifconfig_vlan.py b/python/vyos/ifconfig_vlan.py
index ec4d1da42..53a77c651 100644
--- a/python/vyos/ifconfig_vlan.py
+++ b/python/vyos/ifconfig_vlan.py
@@ -87,6 +87,9 @@ def apply_vlan_config(vlan, config):
     if config['dhcpv6_temporary']:
         vlan.dhcp.v6.options['dhcpv6_temporary'] = True
 
+    if config['dhcpv6_pd_length']:
+        vlan.dhcp.v6.options['dhcpv6_pd_length'] = config['dhcpv6_pd_length']
+
     if config['dhcpv6_pd_interfaces']:
         vlan.dhcp.v6.options['dhcpv6_pd_interfaces'] = config['dhcpv6_pd_interfaces']
 
diff --git a/src/conf_mode/interfaces-bonding.py b/src/conf_mode/interfaces-bonding.py
index b531e97fc..ed9b754c3 100755
--- a/src/conf_mode/interfaces-bonding.py
+++ b/src/conf_mode/interfaces-bonding.py
@@ -299,6 +299,9 @@ def apply(bond):
         if bond['dhcpv6_temporary']:
             b.dhcp.v6.options['dhcpv6_temporary'] = True
 
+        if bond['dhcpv6_pd_length']:
+            b.dhcp.v6.options['dhcpv6_pd_length'] = bond['dhcpv6_pd_length']
+
         if bond['dhcpv6_pd_interfaces']:
             b.dhcp.v6.options['dhcpv6_pd_interfaces'] = bond['dhcpv6_pd_interfaces']
 
diff --git a/src/conf_mode/interfaces-bridge.py b/src/conf_mode/interfaces-bridge.py
index 865d8a999..adfa81c74 100755
--- a/src/conf_mode/interfaces-bridge.py
+++ b/src/conf_mode/interfaces-bridge.py
@@ -321,6 +321,9 @@ def apply(bridge):
         if bridge['dhcpv6_temporary']:
             br.dhcp.v6.options['dhcpv6_temporary'] = True
 
+        if bridge['dhcpv6_pd_length']:
+            br.dhcp.v6.options['dhcpv6_pd_length'] = br['dhcpv6_pd_length']
+
         if bridge['dhcpv6_pd_interfaces']:
             br.dhcp.v6.options['dhcpv6_pd_interfaces'] = br['dhcpv6_pd_interfaces']
 
diff --git a/src/conf_mode/interfaces-ethernet.py b/src/conf_mode/interfaces-ethernet.py
index 8ffefc7cf..e9cab4be7 100755
--- a/src/conf_mode/interfaces-ethernet.py
+++ b/src/conf_mode/interfaces-ethernet.py
@@ -201,6 +201,9 @@ def apply(eth):
         if eth['dhcpv6_temporary']:
             e.dhcp.v6.options['dhcpv6_temporary'] = True
 
+        if eth['dhcpv6_pd_length']:
+            e.dhcp.v6.options['dhcpv6_pd_length'] = eth['dhcpv6_pd_length']
+
         if eth['dhcpv6_pd_interfaces']:
             e.dhcp.v6.options['dhcpv6_pd_interfaces'] = eth['dhcpv6_pd_interfaces']
 
diff --git a/src/conf_mode/interfaces-pppoe.py b/src/conf_mode/interfaces-pppoe.py
index e8aeb810f..eaa61cdb6 100755
--- a/src/conf_mode/interfaces-pppoe.py
+++ b/src/conf_mode/interfaces-pppoe.py
@@ -36,6 +36,7 @@ default_config_data = {
     'deleted': False,
     'description': '\0',
     'disable': False,
+    'dhcpv6_pd_length': '',
     'dhcpv6_pd_interfaces': [],
     'intf': '',
     'idle_timeout': '',
@@ -142,6 +143,11 @@ def get_config():
                                       'dhcpv6-options', 'prefix-delegation']
         conf.set_level(dhcpv6_pd_path)
 
+        # retriebe DHCPv6-PD prefix helper length as some ISPs only hand out a
+        # /64 by default (https://phabricator.vyos.net/T2506)
+        if conf.exists(['length']):
+            pppoe['dhcpv6_pd_length'] = conf.return_value(['length'])
+
         for interface in conf.list_nodes(['interface']):
             conf.set_level(dhcpv6_pd_path + ['interface', interface])
             pd = {
diff --git a/src/conf_mode/interfaces-pseudo-ethernet.py b/src/conf_mode/interfaces-pseudo-ethernet.py
index c1f52d42c..c09df15e8 100755
--- a/src/conf_mode/interfaces-pseudo-ethernet.py
+++ b/src/conf_mode/interfaces-pseudo-ethernet.py
@@ -171,6 +171,9 @@ def apply(peth):
     if peth['dhcpv6_temporary']:
         p.dhcp.v6.options['dhcpv6_temporary'] = True
 
+    if peth['dhcpv6_pd_length']:
+        p.dhcp.v6.options['dhcpv6_pd_length'] = peth['dhcpv6_pd_length']
+
     if peth['dhcpv6_pd_interfaces']:
         p.dhcp.v6.options['dhcpv6_pd_interfaces'] = peth['dhcpv6_pd_interfaces']
 
diff --git a/src/conf_mode/interfaces-wireless.py b/src/conf_mode/interfaces-wireless.py
index 54420acd1..8a2736a66 100755
--- a/src/conf_mode/interfaces-wireless.py
+++ b/src/conf_mode/interfaces-wireless.py
@@ -591,6 +591,9 @@ def apply(wifi):
         if wifi['dhcpv6_temporary']:
             w.dhcp.v6.options['dhcpv6_temporary'] = True
 
+        if wifi['dhcpv6_pd_length']:
+            w.dhcp.v6.options['dhcpv6_pd_length'] = wifi['dhcpv6_pd_length']
+
         if wifi['dhcpv6_pd_interfaces']:
             w.dhcp.v6.options['dhcpv6_pd_interfaces'] = wifi['dhcpv6_pd_interfaces']