T7390: VPP CGNAT implementation (#30)

CLI:
```
set vpp nat cgnat interface outside <interface>        # multi
set vpp nat cgnat interface inside <interface>         # multi

set vpp nat cgnat rule <rule> outside-prefix <prefix>
set vpp nat cgnat rule <rule> inside-prefix <prefix>

set vpp nat cgnat timeout udp <sec>                # default 300
set vpp nat cgnat timeout tcp-established <sec>    # default 7440
set vpp nat cgnat timeout tcp-transitory <sec>     # default 240
set vpp nat cgnat timeout icmp <sec>               # default 60
```
OP mode:
```
show vpp nat cgnat interfaces
show vpp nat cgnat mappings
show vpp nat cgnat sessions

clear vpp cgnat inside-address <address> port <port> external-address <address> port <port>
```

2 files changed, 108 insertions, 1 deletions

diff --git a/python/vyos/vpp/nat/__init__.py b/python/vyos/vpp/nat/__init__.py
index bbd011435..16685c9cc 100644
--- a/python/vyos/vpp/nat/__init__.py
+++ b/python/vyos/vpp/nat/__init__.py
@@ -1,3 +1,4 @@
 from .nat44 import Nat44
+from .det44 import Det44
 
-__all__ = ['Nat44']
+__all__ = ['Nat44', 'Det44']
diff --git a/python/vyos/vpp/nat/det44.py b/python/vyos/vpp/nat/det44.py
new file mode 100644
index 000000000..1046d7cf9
--- /dev/null
+++ b/python/vyos/vpp/nat/det44.py
@@ -0,0 +1,106 @@
+#
+# 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.vpp import VPPControl
+
+
+class Det44:
+    def __init__(self):
+        self.vpp = VPPControl()
+
+    def enable_det44_plugin(self):
+        """Enable DET44 plugin
+        Example:
+            from vyos.vpp.nat import Det44
+            det44 = Det44()
+            det44.enable_det44_plugin()
+        https://github.com/FDio/vpp/blob/stable/2410/src/plugins/nat/det44/det44.api
+        """
+        self.vpp.api.det44_plugin_enable_disable(enable=True)
+
+    def disable_det44_plugin(self):
+        """Disable DET44 plugin"""
+        self.vpp.api.det44_plugin_enable_disable(enable=False)
+
+    def add_det44_interface_outside(self, interface_out):
+        """Add DET44 outside interface"""
+        self.vpp.api.det44_interface_add_del_feature(
+            sw_if_index=self.vpp.get_sw_if_index(interface_out),
+            is_inside=False,
+            is_add=True,
+        )
+
+    def delete_det44_interface_outside(self, interface_out):
+        """Delete DET44 outside interface"""
+        self.vpp.api.det44_interface_add_del_feature(
+            sw_if_index=self.vpp.get_sw_if_index(interface_out),
+            is_inside=False,
+            is_add=False,
+        )
+
+    def add_det44_interface_inside(self, interface_in):
+        """Add DET44 inside interface"""
+        self.vpp.api.det44_interface_add_del_feature(
+            sw_if_index=self.vpp.get_sw_if_index(interface_in),
+            is_inside=True,
+            is_add=True,
+        )
+
+    def delete_det44_interface_inside(self, interface_in):
+        """Delete DET44 inside interface"""
+        self.vpp.api.det44_interface_add_del_feature(
+            sw_if_index=self.vpp.get_sw_if_index(interface_in),
+            is_inside=True,
+            is_add=False,
+        )
+
+    def add_det44_mapping(self, in_addr, in_plen, out_addr, out_plen):
+        """Add DET44 mapping"""
+        self.vpp.api.det44_add_del_map(
+            in_addr=in_addr,
+            in_plen=in_plen,
+            out_addr=out_addr,
+            out_plen=out_plen,
+            is_add=True,
+        )
+
+    def delete_det44_mapping(self, in_addr, in_plen, out_addr, out_plen):
+        """Delete DET44 mapping"""
+        self.vpp.api.det44_add_del_map(
+            in_addr=in_addr,
+            in_plen=in_plen,
+            out_addr=out_addr,
+            out_plen=out_plen,
+            is_add=False,
+        )
+
+    def set_det44_timeouts(
+        self, icmp: int, udp: int, tcp_established: int, tcp_transitory: int
+    ):
+        """Set DET44 timeouts
+        Args:
+            tcp_established (int): TCP established timeout
+            tcp_transitory (int): TCP transitory timeout
+            udp (int): UDP timeout
+            icmp (int): ICMP timeout
+        """
+        self.vpp.api.det44_set_timeouts(
+            icmp=icmp,
+            udp=udp,
+            tcp_established=tcp_established,
+            tcp_transitory=tcp_transitory,
+        )