1 files changed, 112 insertions, 0 deletions
diff --git a/src/conf_mode/protocols_bfd.py b/src/conf_mode/protocols_bfd.py
new file mode 100644
index 0000000..1361bb1
--- /dev/null
+++ b/src/conf_mode/protocols_bfd.py
@@ -0,0 +1,112 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2019-2024 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 vyos.config import Config
+from vyos.configverify import verify_vrf
+from vyos.template import is_ipv6
+from vyos.template import render_to_string
+from vyos.utils.network import is_ipv6_link_local
+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', 'bfd']
+    bfd = conf.get_config_dict(base, key_mangling=('-', '_'),
+                               get_first_key=True,
+                               no_tag_node_value_mangle=True)
+    # Bail out early if configuration tree does not exist
+    if not conf.exists(base):
+        return bfd
+
+    bfd = conf.merge_defaults(bfd, recursive=True)
+
+    return bfd
+
+def verify(bfd):
+    if not bfd:
+        return None
+
+    if 'peer' in bfd:
+        for peer, peer_config in bfd['peer'].items():
+            # IPv6 link local peers require an explicit local address/interface
+            if is_ipv6_link_local(peer):
+                if 'source' not in peer_config or len(peer_config['source']) < 2:
+                    raise ConfigError('BFD IPv6 link-local peers require explicit local address and interface setting')
+
+            # IPv6 peers require an explicit local address
+            if is_ipv6(peer):
+                if 'source' not in peer_config or 'address' not in peer_config['source']:
+                    raise ConfigError('BFD IPv6 peers require explicit local address setting')
+
+            if 'multihop' in peer_config:
+                # multihop require source address
+                if 'source' not in peer_config or 'address' not in peer_config['source']:
+                    raise ConfigError('BFD multihop require source address')
+
+                # multihop and echo-mode cannot be used together
+                if 'echo_mode' in peer_config:
+                    raise ConfigError('BFD multihop and echo-mode cannot be used together')
+
+                # multihop doesn't accept interface names
+                if 'source' in peer_config and 'interface' in peer_config['source']:
+                    raise ConfigError('BFD multihop and source interface cannot be used together')
+
+            if 'minimum_ttl' in peer_config and 'multihop' not in peer_config:
+                raise ConfigError('Minimum TTL is only available for multihop BFD sessions!')
+
+            if 'profile' in peer_config:
+                profile_name = peer_config['profile']
+                if 'profile' not in bfd or profile_name not in bfd['profile']:
+                    raise ConfigError(f'BFD profile "{profile_name}" does not exist!')
+
+            if 'vrf' in peer_config:
+                verify_vrf(peer_config)
+
+    return None
+
+def generate(bfd):
+    if not bfd:
+        return None
+    bfd['new_frr_config'] = render_to_string('frr/bfdd.frr.j2', bfd)
+
+def apply(bfd):
+    bfd_daemon = 'bfdd'
+
+    # Save original configuration prior to starting any commit actions
+    frr_cfg = frr.FRRConfig()
+    frr_cfg.load_configuration(bfd_daemon)
+    frr_cfg.modify_section('^bfd', stop_pattern='^exit', remove_stop_mark=True)
+    if 'new_frr_config' in bfd:
+        frr_cfg.add_before(frr.default_add_before, bfd['new_frr_config'])
+    frr_cfg.commit_configuration(bfd_daemon)
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)