pim6: T5733: add missing FRR PIM6 related features

(cherry picked from commit 403d2ffd6e46cb082b1d16ddf515e1784bee968c)

# Conflicts:
#	data/templates/frr/pim6d.frr.j2
#	interface-definitions/protocols-pim6.xml.in
#	smoketest/scripts/cli/test_protocols_pim6.py
#	src/conf_mode/protocols_pim6.py

1 files changed, 133 insertions, 0 deletions

diff --git a/src/conf_mode/protocols_pim6.py b/src/conf_mode/protocols_pim6.py
new file mode 100755
index 000000000..2003a1014
--- /dev/null
+++ b/src/conf_mode/protocols_pim6.py
@@ -0,0 +1,133 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from ipaddress import IPv6Address
+from ipaddress import IPv6Network
+from sys import exit
+
+from vyos.config import Config
+from vyos.config import config_dict_merge
+from vyos.configdict import node_changed
+from vyos.configverify import verify_interface_exists
+from vyos.template import render_to_string
+from vyos import ConfigError
+from vyos import frr
+from vyos import airbag
+airbag.enable()
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['protocols', 'pim6']
+    pim6 = conf.get_config_dict(base, key_mangling=('-', '_'),
+                                 get_first_key=True, with_recursive_defaults=True)
+
+    # FRR has VRF support for different routing daemons. As interfaces belong
+    # to VRFs - or the global VRF, we need to check for changed interfaces so
+    # that they will be properly rendered for the FRR config. Also this eases
+    # removal of interfaces from the running configuration.
+    interfaces_removed = node_changed(conf, base + ['interface'])
+    if interfaces_removed:
+        pim6['interface_removed'] = list(interfaces_removed)
+
+    # Bail out early if configuration tree does no longer exist. this must
+    # be done after retrieving the list of interfaces to be removed.
+    if not conf.exists(base):
+        pim6.update({'deleted' : ''})
+        return pim6
+
+    # We have gathered the dict representation of the CLI, but there are default
+    # options which we need to update into the dictionary retrived.
+    default_values = conf.get_config_defaults(**pim6.kwargs, recursive=True)
+
+    pim6 = config_dict_merge(default_values, pim6)
+    return pim6
+
+def verify(pim6):
+    if not pim6 or 'deleted' in pim6:
+        return
+
+    for interface, interface_config in pim6.get('interface', {}).items():
+        verify_interface_exists(interface)
+        if 'mld' in interface_config:
+            mld = interface_config['mld']
+            for group in mld.get('join', {}).keys():
+                # Validate multicast group address
+                if not IPv6Address(group).is_multicast:
+                    raise ConfigError(f"{group} is not a multicast group")
+
+    if 'rp' in pim6:
+        if 'address' not in pim6['rp']:
+            raise ConfigError('PIM6 rendezvous point needs to be defined!')
+
+        # Check unique multicast groups
+        unique = []
+        pim_base_error = 'PIM6 rendezvous point group'
+
+        if {'address', 'prefix-list6'} <= set(pim6['rp']):
+            raise ConfigError(f'{pim_base_error} supports either address or a prefix-list!')
+
+        for address, address_config in pim6['rp']['address'].items():
+            if 'group' not in address_config:
+                raise ConfigError(f'{pim_base_error} should be defined for "{address}"!')
+
+            # Check if it is a multicast group
+            for gr_addr in address_config['group']:
+                if not IPv6Network(gr_addr).is_multicast:
+                    raise ConfigError(f'{pim_base_error} "{gr_addr}" is not a multicast group!')
+                if gr_addr in unique:
+                    raise ConfigError(f'{pim_base_error} must be unique!')
+                unique.append(gr_addr)
+
+def generate(pim6):
+    if not pim6 or 'deleted' in pim6:
+        return
+    pim6['new_frr_config'] = render_to_string('frr/pim6d.frr.j2', pim6)
+    return None
+
+def apply(pim6):
+    if pim6 is None:
+        return
+
+    pim6_daemon = 'pim6d'
+
+    # Save original configuration prior to starting any commit actions
+    frr_cfg = frr.FRRConfig()
+
+    frr_cfg.load_configuration(pim6_daemon)
+
+    for key in ['interface', 'interface_removed']:
+        if key not in pim6:
+            continue
+        for interface in pim6[key]:
+            frr_cfg.modify_section(f'^interface {interface}', stop_pattern='^exit', remove_stop_mark=True)
+
+    if 'new_frr_config' in pim6:
+        frr_cfg.add_before(frr.default_add_before, pim6['new_frr_config'])
+    frr_cfg.commit_configuration(pim6_daemon)
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)