Add BPF-helper test case for CLOCK_TAI access. The added test verifies that:
* Timestamps are generated
* Timestamps are moving forward
* Timestamps are reasonable
Signed-off-by: Kurt Kanzenbach <kurt@xxxxxxxxxxxxx>
---
.../selftests/bpf/prog_tests/time_tai.c | 74 +++++++++++++++++++
.../selftests/bpf/progs/test_time_tai.c | 24 ++++++
2 files changed, 98 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/time_tai.c
create mode 100644 tools/testing/selftests/bpf/progs/test_time_tai.c
diff --git a/tools/testing/selftests/bpf/prog_tests/time_tai.c b/tools/testing/selftests/bpf/prog_tests/time_tai.c
new file mode 100644
index 000000000000..a31119823666
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/time_tai.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2022 Linutronix GmbH */
+
+#include <test_progs.h>
+#include <network_helpers.h>
+
+#include "test_time_tai.skel.h"
+
+#include <time.h>
+#include <stdint.h>
+
+#define TAI_THRESHOLD 1000000000ULL /* 1s */
+#define NSEC_PER_SEC 1000000000ULL
+
+static __u64 ts_to_ns(const struct timespec *ts)
+{
+ return ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec;
+}
+
+void test_time_tai(void)
+{
+ struct __sk_buff skb = {
+ .cb[0] = 0,
+ .cb[1] = 0,
+ .tstamp = 0,
+ };
+ LIBBPF_OPTS(bpf_test_run_opts, topts,
+ .data_in = &pkt_v4,
+ .data_size_in = sizeof(pkt_v4),
+ .ctx_in = &skb,
+ .ctx_size_in = sizeof(skb),
+ .ctx_out = &skb,
+ .ctx_size_out = sizeof(skb),
+ );
+ struct test_time_tai *skel;
+ struct timespec now_tai;
+ __u64 ts1, ts2, now;
+ int ret, prog_fd;
+
+ /* Open and load */
+ skel = test_time_tai__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "tai_open"))
+ return;
+
+ /* Run test program */
+ prog_fd = bpf_program__fd(skel->progs.time_tai);
+ ret = bpf_prog_test_run_opts(prog_fd, &topts);
+ ASSERT_OK(ret, "test_run");
+
+ /* Retrieve generated TAI timestamps */
+ ts1 = skb.tstamp;
+ ts2 = skb.cb[0] | ((__u64)skb.cb[1] << 32);
+
+ /* TAI != 0 */
+ ASSERT_NEQ(ts1, 0, "tai_ts1");
+ ASSERT_NEQ(ts2, 0, "tai_ts2");
+
+ /* TAI is moving forward only */
+ ASSERT_GT(ts2, ts1, "tai_forward");
+
+ /* Check for future */
+ ret = clock_gettime(CLOCK_TAI, &now_tai);
+ ASSERT_EQ(ret, 0, "tai_gettime");
+ now = ts_to_ns(&now_tai);
+
+ ASSERT_TRUE(now > ts1, "tai_future_ts1");
+ ASSERT_TRUE(now > ts2, "tai_future_ts2");
+
+ /* Check for reasonable range */
+ ASSERT_TRUE(now - ts1 < TAI_THRESHOLD, "tai_range_ts1");
+ ASSERT_TRUE(now - ts2 < TAI_THRESHOLD, "tai_range_ts2");
+
+ test_time_tai__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_time_tai.c b/tools/testing/selftests/bpf/progs/test_time_tai.c
new file mode 100644
index 000000000000..7ea0863f3ddb
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_time_tai.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2022 Linutronix GmbH */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+char _license[] SEC("license") = "GPL";
+
+SEC("tc")
+int time_tai(struct __sk_buff *skb)
+{
+ __u64 ts1, ts2;
+
+ /* Get TAI timestamps */
+ ts1 = bpf_ktime_get_tai_ns();
+ ts2 = bpf_ktime_get_tai_ns();
+
+ /* Save TAI timestamps (Note: skb->hwtstamp is read-only) */
+ skb->tstamp = ts1;
+ skb->cb[0] = ts2 & 0xffffffff;
+ skb->cb[1] = ts2 >> 32;
+
+ return 0;
+}
--
2.30.2
