xref: /linux/tools/testing/selftests/bpf/progs/test_time_tai.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004) 
1*64e15820SKurt Kanzenbach // SPDX-License-Identifier: GPL-2.0
2*64e15820SKurt Kanzenbach /* Copyright (C) 2022 Linutronix GmbH */
3*64e15820SKurt Kanzenbach 
4*64e15820SKurt Kanzenbach #include <linux/bpf.h>
5*64e15820SKurt Kanzenbach #include <bpf/bpf_helpers.h>
6*64e15820SKurt Kanzenbach 
7*64e15820SKurt Kanzenbach char _license[] SEC("license") = "GPL";
8*64e15820SKurt Kanzenbach 
9*64e15820SKurt Kanzenbach SEC("tc")
time_tai(struct __sk_buff * skb)10*64e15820SKurt Kanzenbach int time_tai(struct __sk_buff *skb)
11*64e15820SKurt Kanzenbach {
12*64e15820SKurt Kanzenbach 	__u64 ts1, ts2;
13*64e15820SKurt Kanzenbach 
14*64e15820SKurt Kanzenbach 	/* Get TAI timestamps */
15*64e15820SKurt Kanzenbach 	ts1 = bpf_ktime_get_tai_ns();
16*64e15820SKurt Kanzenbach 	ts2 = bpf_ktime_get_tai_ns();
17*64e15820SKurt Kanzenbach 
18*64e15820SKurt Kanzenbach 	/* Save TAI timestamps (Note: skb->hwtstamp is read-only) */
19*64e15820SKurt Kanzenbach 	skb->tstamp = ts1;
20*64e15820SKurt Kanzenbach 	skb->cb[0] = ts2 & 0xffffffff;
21*64e15820SKurt Kanzenbach 	skb->cb[1] = ts2 >> 32;
22*64e15820SKurt Kanzenbach 
23*64e15820SKurt Kanzenbach 	return 0;
24*64e15820SKurt Kanzenbach }
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