Merge pull request #16 from sever-sever/T7181

T7181: VPP add initial source NAT implentation

2 files changed, 123 insertions, 0 deletions

diff --git a/src/conf_mode/vpp.py b/src/conf_mode/vpp.py
index 90a3bb7fb..1f4c6c0f0 100755
--- a/src/conf_mode/vpp.py
+++ b/src/conf_mode/vpp.py
@@ -135,6 +135,10 @@ def get_config(config=None):
             # to be reinitialized after the commit
             set_dependents('ethernet', conf, removed_iface)
 
+    # NAT dependency
+    if conf.exists(['vpp', 'nat44', 'source']):
+        set_dependents('vpp_nat_source', conf)
+
     if not conf.exists(base):
         return {
             'removed_ifaces': removed_ifaces,
diff --git a/src/conf_mode/vpp_nat_source.py b/src/conf_mode/vpp_nat_source.py
new file mode 100644
index 000000000..2e1884c3a
--- /dev/null
+++ b/src/conf_mode/vpp_nat_source.py
@@ -0,0 +1,119 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2025 VyOS Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# 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, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+from vyos.config import Config
+from vyos import ConfigError
+from vyos.vpp.nat.nat44 import Nat44
+
+
+def get_config(config=None) -> dict:
+    if config:
+        conf = config
+    else:
+        conf = Config()
+
+    base = ['vpp', 'nat44', 'source']
+
+    # Get config_dict with default values
+    config = conf.get_config_dict(
+        base,
+        key_mangling=('-', '_'),
+        get_first_key=True,
+        no_tag_node_value_mangle=True,
+        with_defaults=True,
+        with_recursive_defaults=True,
+    )
+
+    # Get effective config as we need full dicitonary per interface delete
+    effective_config = conf.get_config_dict(
+        base,
+        key_mangling=('-', '_'),
+        effective=True,
+        get_first_key=True,
+        no_tag_node_value_mangle=True,
+    )
+
+    if not config:
+        config['remove'] = True
+
+    if effective_config:
+        config.update({'effective': effective_config})
+
+    return config
+
+
+def verify(config):
+    if 'remove' in config:
+        return None
+
+    required_keys = {'inbound_interface', 'outbound_interface'}
+    if not all(key in config for key in required_keys):
+        missing_keys = required_keys - set(config.keys())
+        raise ConfigError(
+            f"Required options are missing: {', '.join(missing_keys).replace('_', '-')}"
+        )
+
+    if not config.get('translation', {}).get('address'):
+        raise ConfigError('Translation requires address')
+
+    if config.get('translation', {}).get('address') == 'masquerade':
+        raise ConfigError('Masquerade is not implemented')
+
+
+def generate(config):
+    pass
+
+
+def apply(config):
+    # Delete NAT source
+    if 'effective' in config:
+        remove_config = config.get('effective')
+        interface_in = remove_config.get('inbound_interface')
+        interface_out = remove_config.get('outbound_interface')
+        translation_address = remove_config.get('translation', {}).get('address')
+
+        n = Nat44(interface_in, interface_out, translation_address)
+        n.delete_nat44_out_interface()
+        n.delete_nat44_interface_inside()
+        n.delete_nat44_address_range()
+
+    if 'remove' in config:
+        return None
+
+    # Add NAT44
+    interface_in = config.get('inbound_interface')
+    interface_out = config.get('outbound_interface')
+    translation_address = config.get('translation', {}).get('address')
+
+    n = Nat44(interface_in, interface_out, translation_address)
+    n.enable_nat44_ed()
+    n.enable_nat44_forwarding()
+    n.add_nat44_out_interface()
+    # n.add_nat44_interface_inside()
+    n.add_nat44_address_range()
+
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)