From cecaf298bba02e085cffeb1ba996a0bd0ed24961 Mon Sep 17 00:00:00 2001
From: YueGuobin <yueguobin@outlook.com>
Date: Wed, 30 Sep 2026 10:00:38 +0800
Subject: [PATCH] feat(controller): expose kernel_datapath on the link payload
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Runtime fact recomputed from the NIO wiring on every load (not
persisted). Without it clients cannot tell a relay link from a kernel
link whose compute lacks a filter capability — both show up as
kernel-only types missing from available_filters.
---
 gns3server/controller/link.py | 5 +++++
 tests/controller/test_link.py | 1 +
 2 files changed, 6 insertions(+)

diff --git a/gns3server/controller/link.py b/gns3server/controller/link.py
index 4a324bb65..337df9e29 100644
--- a/gns3server/controller/link.py
+++ b/gns3server/controller/link.py
@@ -847,6 +847,11 @@ class Link:
             "capture_file_path": self.capture_file_path,
             "capture_compute_id": self.capture_compute_id,
             "link_type": self._link_type,
+            # runtime fact, not persisted: recomputed from the NIO wiring on
+            # every load (tells clients which datapath impairs this link —
+            # kernel-only filter types absent from available_filters are
+            # then distinguishable from capability gaps)
+            "kernel_datapath": self.kernel_datapath,
             "filters": self._filters,
             "markers": self._markers,
             "suspend": self._suspended,
diff --git a/tests/controller/test_link.py b/tests/controller/test_link.py
index 12436abb5..66a94e708 100644
--- a/tests/controller/test_link.py
+++ b/tests/controller/test_link.py
@@ -228,6 +228,7 @@ async def test_json(project, compute):
         "suspend": False,
         "wireshark": False,
         "link_type": "ethernet",
+        "kernel_datapath": False,
         "capturing": False,
         "capture_file_name": None,
         "capture_file_path": None,