On 7/8/24 6:31 AM, Daniel Borkmann wrote:
Add a test case which replaces an active ingress qdisc while keeping the
miniq in-tact during the transition period to the new clsact qdisc.
Thanks for the explanation in patch 1 fix and the test. Applied.
# ./vmtest.sh -- ./test_progs -t tc_link
[...]
./test_progs -t tc_link
[ 3.412871] bpf_testmod: loading out-of-tree module taints kernel.
[ 3.413343] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
#332 tc_links_after:OK
#333 tc_links_append:OK
#334 tc_links_basic:OK
#335 tc_links_before:OK
#336 tc_links_chain_classic:OK
#337 tc_links_chain_mixed:OK
#338 tc_links_dev_chain0:OK
#339 tc_links_dev_cleanup:OK
#340 tc_links_dev_mixed:OK
#341 tc_links_ingress:OK
#342 tc_links_invalid:OK
#343 tc_links_prepend:OK
#344 tc_links_replace:OK
#345 tc_links_revision:OK
Summary: 14/0 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
---
tools/testing/selftests/bpf/config | 3 +
.../selftests/bpf/prog_tests/tc_links.c | 61 +++++++++++++++++++
2 files changed, 64 insertions(+)
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index c0ef168eb637..c95f6f1ab74a 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -61,9 +61,12 @@ CONFIG_MPLS=y
CONFIG_MPLS_IPTUNNEL=y
CONFIG_MPLS_ROUTING=y
CONFIG_MPTCP=y
+CONFIG_NET_ACT_SKBMOD=y
+CONFIG_NET_CLS=y
CONFIG_NET_CLS_ACT=y
CONFIG_NET_CLS_BPF=y
CONFIG_NET_CLS_FLOWER=y
+CONFIG_NET_CLS_MATCHALL=y
CONFIG_NET_FOU=y
CONFIG_NET_FOU_IP_TUNNELS=y
CONFIG_NET_IPGRE=y
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_links.c b/tools/testing/selftests/bpf/prog_tests/tc_links.c
index bc9841144685..1af9ec1149aa 100644
--- a/tools/testing/selftests/bpf/prog_tests/tc_links.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_links.c
@@ -9,6 +9,8 @@
#define ping_cmd "ping -q -c1 -w1 127.0.0.1 > /dev/null"
#include "test_tc_link.skel.h"
+
+#include "netlink_helpers.h"
#include "tc_helpers.h"
void serial_test_tc_links_basic(void)
@@ -1787,6 +1789,65 @@ void serial_test_tc_links_ingress(void)
test_tc_links_ingress(BPF_TCX_INGRESS, false, false);
}
+struct qdisc_req {
+ struct nlmsghdr n;
+ struct tcmsg t;
+ char buf[1024];
+};
+
+static int qdisc_replace(int ifindex, const char *kind, bool block)
+{
+ struct rtnl_handle rth = { .fd = -1 };
+ struct qdisc_req req;
+ int err;
+
+ err = rtnl_open(&rth, 0);
+ if (!ASSERT_OK(err, "open_rtnetlink"))
+ return err;
+
+ memset(&req, 0, sizeof(req));
+ req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
+ req.n.nlmsg_flags = NLM_F_CREATE | NLM_F_REPLACE | NLM_F_REQUEST;
+ req.n.nlmsg_type = RTM_NEWQDISC;
+ req.t.tcm_family = AF_UNSPEC;
+ req.t.tcm_ifindex = ifindex;
+ req.t.tcm_parent = 0xfffffff1;
+
+ addattr_l(&req.n, sizeof(req), TCA_KIND, kind, strlen(kind) + 1);
+ if (block)
+ addattr32(&req.n, sizeof(req), TCA_INGRESS_BLOCK, 1);
+
+ err = rtnl_talk(&rth, &req.n, NULL);
+ ASSERT_OK(err, "talk_rtnetlink");
+ rtnl_close(&rth);
+ return err;
+}
+
+void serial_test_tc_links_dev_chain0(void)
+{
+ int err, ifindex;
+
+ ASSERT_OK(system("ip link add dev foo type veth peer name bar"), "add veth");
+ ifindex = if_nametoindex("foo");
+ ASSERT_NEQ(ifindex, 0, "non_zero_ifindex");
+ err = qdisc_replace(ifindex, "ingress", true);
+ if (!ASSERT_OK(err, "attaching ingress"))
+ goto cleanup;
+ ASSERT_OK(system("tc filter add block 1 matchall action skbmod swap mac"), "add block");
+ err = qdisc_replace(ifindex, "clsact", false);
+ if (!ASSERT_OK(err, "attaching clsact"))
+ goto cleanup;
+ /* Heuristic: kern_sync_rcu() alone does not work; a wait-time of ~5s
+ * triggered the issue without the fix reliably 100% of the time.
+ */
+ sleep(5);
It may be handy to be able to trigger rcu_barrier() to wait for the pending rcu
callbacks to finish. Not sure if there is an existing way to do that without
introducing a kfunc in bpf_testmod. Probably something to think about as an
optimization.
Thanks for the fix and the test. Applied.
+ ASSERT_OK(system("tc filter add dev foo ingress matchall action skbmod swap mac"), "add filter");
+cleanup:
+ ASSERT_OK(system("ip link del dev foo"), "del veth");
+ ASSERT_EQ(if_nametoindex("foo"), 0, "foo removed");
+ ASSERT_EQ(if_nametoindex("bar"), 0, "bar removed");
+}
+
static void test_tc_links_dev_mixed(int target)
{
LIBBPF_OPTS(bpf_tc_opts, tc_opts, .handle = 1, .priority = 1);
