T6641: Add vyos-network-event-logger Service

The service parses and logs network events for improved monitoring and diagnostics.
Supported event types include:

- `RTM_NEWROUTE`, `RTM_DELROUTE`
- `RTM_NEWLINK`, `RTM_DELLINK`
- `RTM_NEWADDR`, `RTM_DELADDR`
- `RTM_NEWNEIGH`, `RTM_DELNEIGH`, `RTM_GETNEIGH`
- `RTM_NEWRULE`, `RTM_DELRULE`

Added operational mode commands for filtered log retrieval:
- `show log network-event <event-type> <interface>`: Retrieve logs filtered by event type and interface.
- `show interfaces <type> <name> event-log <event-type>`: Display interface-specific logs filtered by event type.

1 files changed, 38 insertions, 0 deletions

diff --git a/python/vyos/include/uapi/linux/lwtunnel.py b/python/vyos/include/uapi/linux/lwtunnel.py
new file mode 100644
index 000000000..6797a762b
--- /dev/null
+++ b/python/vyos/include/uapi/linux/lwtunnel.py
@@ -0,0 +1,38 @@
+# Copyright (C) 2025 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/>.
+
+LWTUNNEL_ENCAP_NONE = 0
+LWTUNNEL_ENCAP_MPLS = 1
+LWTUNNEL_ENCAP_IP = 2
+LWTUNNEL_ENCAP_ILA = 3
+LWTUNNEL_ENCAP_IP6 = 4
+LWTUNNEL_ENCAP_SEG6 = 5
+LWTUNNEL_ENCAP_BPF = 6
+LWTUNNEL_ENCAP_SEG6_LOCAL = 7
+LWTUNNEL_ENCAP_RPL = 8
+LWTUNNEL_ENCAP_IOAM6 = 9
+LWTUNNEL_ENCAP_XFRM = 10
+
+ENCAP_TO_NAME = {
+    LWTUNNEL_ENCAP_MPLS: 'mpls',
+    LWTUNNEL_ENCAP_IP: 'ip',
+    LWTUNNEL_ENCAP_IP6: 'ip6',
+    LWTUNNEL_ENCAP_ILA: 'ila',
+    LWTUNNEL_ENCAP_BPF: 'bpf',
+    LWTUNNEL_ENCAP_SEG6: 'seg6',
+    LWTUNNEL_ENCAP_SEG6_LOCAL: 'seg6local',
+    LWTUNNEL_ENCAP_RPL: 'rpl',
+    LWTUNNEL_ENCAP_IOAM6: 'ioam6',
+    LWTUNNEL_ENCAP_XFRM: 'xfrm',
+}