The test makes requests with RTM_GETLINK and TARGET_NETNS and verifies that reported LINK_NSID is correct and only reported when it is needed from the querier's perspective.
Assisted-by: OpenCode:claude-opus-4.6 Signed-off-by: Ilya Maximets <[email protected]> --- tools/testing/selftests/net/link_netns.py | 49 ++++++++++++++++++++++- 1 file changed, 47 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/net/link_netns.py b/tools/testing/selftests/net/link_netns.py index aab043c59d695..2aae422d3f8a6 100755 --- a/tools/testing/selftests/net/link_netns.py +++ b/tools/testing/selftests/net/link_netns.py @@ -3,13 +3,14 @@ import time -from lib.py import ksft_run, ksft_exit, ksft_true +from lib.py import ksft_run, ksft_exit, ksft_eq, ksft_true from lib.py import ip from lib.py import NetNS, NetNSEnter from lib.py import RtnlFamily LINK_NETNSID = 100 +LINK_NETNSID2 = 200 def test_event() -> None: @@ -132,8 +133,52 @@ def test_peer_net() -> None: ip(f"link del foo", ns=tgt_net) +def test_peer_net_cross_ns() -> None: + """Cross-namespace RTM_GETLINK queries using target-netnsid. + IFLA_LINK_NETNSID should report the link peer's namespace from the + querier's perspective. Absent means the peer is in the querier's + own namespace. Must not create self-referential nsid mappings.""" + + with NetNS() as ns1, NetNS() as ns2, NetNS() as ns3: + net1, net2, net3 = str(ns1), str(ns2), str(ns3) + + ip(f"netns set {net2} {LINK_NETNSID}", ns=net1) + ip(f"netns set {net3} {LINK_NETNSID2}", ns=net1) + + with NetNSEnter(net1): + rtnl = RtnlFamily() + + cases = [ + # "dev netns", "peer netns", "query nsid", expected link-netnsid. + (net2, net1, LINK_NETNSID, None), + (net2, net2, LINK_NETNSID, LINK_NETNSID), + (net2, net3, LINK_NETNSID, LINK_NETNSID2), + ] + + for dev_ns, peer_ns, query_nsid, exp in cases: + ip(f"link add foo netns {dev_ns} type veth" + f" peer name bar netns {peer_ns}") + + resp = rtnl.getlink({"target-netnsid": query_nsid, + "ifname": "foo"}) + ksft_eq(resp.get("link-netnsid"), exp, + f"link-netnsid mismatch for dev={dev_ns} peer={peer_ns}") + + ip("link del foo", ns=dev_ns) + + # Verify no extra nsid was created by the queries. + nsids = ip("netns list-id", ns=net1, json=True) + ksft_eq(len(nsids), 2, + f"unexpected nsid mappings after cross-ns queries: {nsids}") + + def main() -> None: - ksft_run([test_event, test_link_net, test_peer_net]) + ksft_run([ + test_event, + test_link_net, + test_peer_net, + test_peer_net_cross_ns, + ]) ksft_exit() -- 2.53.0
