[PATCH 6.1 41/64] selftests: mptcp: pm: ensure unknown flags are ignored

Greg Kroah-Hartman
2026-02-17T20:47:14Z

From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>

commit 29f4801e9c8dfd12bdcb33b61a6ac479c7162bd7 upstream.

This validates the previous commit: the userspace can set unknown flags
-- the 7th bit is currently unused -- without errors, but only the
supported ones are printed in the endpoints dumps.

The 'Fixes' tag here below is the same as the one from the previous
commit: this patch here is not fixing anything wrong in the selftests,
but it validates the previous fix for an issue introduced by this commit
ID.

Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-2-9e4781a6c1b8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in pm_netlink.sh, because some refactoring have been done
later on: commit 0d16ed0c2e74 ("selftests: mptcp: add
{get,format}_endpoint(s) helpers") and commit c99d57d0007a
("selftests: mptcp: use pm_nl endpoint ops") are not in this version.
The same operation can still be done at the same place, without using
the new helpers.
Also, commit 1dc88d241f92 ("selftests: mptcp: pm_nl_ctl: always look
for errors") is not in this version, and create a conflict in the
context which is not related to the modification here. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/testing/selftests/net/mptcp/pm_netlink.sh | 4 ++++
tools/testing/selftests/net/mptcp/pm_nl_ctl.c | 11 +++++++++++
2 files changed, 15 insertions(+)

--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh
@@ -124,6 +124,10 @@ id 8 flags signal 10.0.1.8" "id limit"
ip netns exec $ns1 ./pm_nl_ctl flush
check "ip netns exec $ns1 ./pm_nl_ctl dump" "" "flush addrs"

+ip netns exec $ns1 ./pm_nl_ctl add 10.0.1.1 flags unknown
+check "ip netns exec $ns1 ./pm_nl_ctl dump" "id 1 flags 10.0.1.1" "ignore unknown flags"
+ip netns exec $ns1 ./pm_nl_ctl flush
+
ip netns exec $ns1 ./pm_nl_ctl limits 9 1
check "ip netns exec $ns1 ./pm_nl_ctl limits" "$default_limits" "rcv addrs above hard limit"

--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -29,6 +29,8 @@
#define IPPROTO_MPTCP 262
#endif

+#define MPTCP_PM_ADDR_FLAG_UNKNOWN _BITUL(7)
+
static void syntax(char *argv[])
{
fprintf(stderr, "%s add|ann|rem|csf|dsf|get|set|del|flush|dump|events|listen|accept [<args>]\n", argv[0]);
@@ -814,6 +816,8 @@ int add_addr(int fd, int pm_family, int
flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
else if (!strcmp(tok, "fullmesh"))
flags |= MPTCP_PM_ADDR_FLAG_FULLMESH;
+ else if (!strcmp(tok, "unknown"))
+ flags |= MPTCP_PM_ADDR_FLAG_UNKNOWN;
else
error(1, errno,
"unknown flag %s", argv[arg]);
@@ -1018,6 +1022,13 @@ static void print_addr(struct rtattr *at
if (flags)
printf(",");
}
+
+ if (flags & MPTCP_PM_ADDR_FLAG_UNKNOWN) {
+ printf("unknown");
+ flags &= ~MPTCP_PM_ADDR_FLAG_UNKNOWN;
+ if (flags)
+ printf(",");
+ }

/* bump unknown flags, if any */
if (flags)