nhrp: T3599: Migrate NHRP to XML/Python

1 files changed, 122 insertions, 0 deletions

diff --git a/src/conf_mode/protocols_nhrp.py b/src/conf_mode/protocols_nhrp.py
new file mode 100755
index 000000000..12dacdba0
--- /dev/null
+++ b/src/conf_mode/protocols_nhrp.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 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.configdict import node_changed
+from vyos.template import render
+from vyos.util import process_named_running
+from vyos.util import run
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+opennhrp_conf = '/run/opennhrp/opennhrp.conf'
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['protocols', 'nhrp']
+
+    nhrp = conf.get_config_dict(base, key_mangling=('-', '_'),
+                                get_first_key=True, no_tag_node_value_mangle=True)
+    nhrp['del_tunnels'] = node_changed(conf, base + ['tunnel'], key_mangling=('-', '_'))
+
+    if not conf.exists(base):
+        return nhrp
+
+    nhrp['if_tunnel'] = conf.get_config_dict(['interfaces', 'tunnel'], key_mangling=('-', '_'),
+                                get_first_key=True, no_tag_node_value_mangle=True)
+
+    nhrp['profile_map'] = {}
+    profile = conf.get_config_dict(['vpn', 'ipsec', 'profile'], key_mangling=('-', '_'),
+                                get_first_key=True, no_tag_node_value_mangle=True)
+
+    for name, profile_conf in profile.items():
+        if 'bind' in profile_conf and 'tunnel' in profile_conf['bind']:
+            interfaces = profile_conf['bind']['tunnel']
+            if isinstance(interfaces, str):
+                interfaces = [interfaces]
+            for interface in interfaces:
+                nhrp['profile_map'][interface] = name
+
+    return nhrp
+
+def verify(nhrp):
+    if 'tunnel' in nhrp:
+        for name, nhrp_conf in nhrp['tunnel'].items():
+            if not nhrp['if_tunnel'] or name not in nhrp['if_tunnel']:
+                raise ConfigError(f'Tunnel interface "{name}" does not exist')
+
+            tunnel_conf = nhrp['if_tunnel'][name]
+
+            if 'encapsulation' not in tunnel_conf or tunnel_conf['encapsulation'] != 'gre':
+                raise ConfigError(f'Tunnel "{name}" is not an mGRE tunnel')
+
+            if 'remote' in tunnel_conf:
+                raise ConfigError(f'Tunnel "{name}" cannot have a remote address defined')
+
+            if 'map' in nhrp_conf:
+                for map_name, map_conf in nhrp_conf['map'].items():
+                    if 'nbma_address' not in map_conf:
+                        raise ConfigError(f'nbma-address missing on map {map_name} on tunnel {name}')
+
+            if 'dynamic_map' in nhrp_conf:
+                for map_name, map_conf in nhrp_conf['dynamic_map'].items():
+                    if 'nbma_domain_name' not in map_conf:
+                        raise ConfigError(f'nbma-domain-name missing on dynamic-map {map_name} on tunnel {name}')
+    return None
+
+def generate(nhrp):
+    render(opennhrp_conf, 'nhrp/opennhrp.conf.tmpl', nhrp)
+    return None
+
+def apply(nhrp):
+    if 'tunnel' in nhrp:
+        for tunnel, tunnel_conf in nhrp['tunnel'].items():
+            if 'source_address' in tunnel_conf:
+                chain = f'VYOS_NHRP_{tunnel}_OUT_HOOK'
+                source_address = tunnel_conf['source_address']
+
+                chain_exists = run(f'sudo iptables --check {chain} -j RETURN') == 0
+                if not chain_exists:
+                    run(f'sudo iptables --new {chain}')
+                    run(f'sudo iptables --append {chain} -p gre -s {source_address} -d 224.0.0.0/4 -j DROP')
+                    run(f'sudo iptables --append {chain} -j RETURN')
+                    run(f'sudo iptables --insert OUTPUT 2 -j {chain}')
+
+    for tunnel in nhrp['del_tunnels']:
+        chain = f'VYOS_NHRP_{tunnel}_OUT_HOOK'
+        chain_exists = run(f'sudo iptables --check {chain} -j RETURN') == 0
+        if chain_exists:
+            run(f'sudo iptables --delete OUTPUT -j {chain}')
+            run(f'sudo iptables --flush {chain}')
+            run(f'sudo iptables --delete-chain {chain}')
+
+    action = 'restart' if nhrp and 'tunnel' in nhrp else 'stop'
+    run(f'systemctl {action} opennhrp')
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)