net: fix SOF_TIMESTAMPING_BIND_PHC to work with multiple sockets
[ Upstream commit 007747a984ea5e895b7d8b056b24ebf431e1e71d ]
When multiple sockets using the SOF_TIMESTAMPING_BIND_PHC flag received
a packet with a hardware timestamp (e.g. multiple PTP instances in
different PTP domains using the UDPv4/v6 multicast or L2 transport),
the timestamps received on some sockets were corrupted due to repeated
conversion of the same timestamp (by the same or different vclocks).
Fix ptp_convert_timestamp() to not modify the shared skb timestamp
and return the converted timestamp as a ktime_t instead. If the
conversion fails, return 0 to not confuse the application with
timestamps corresponding to an unexpected PHC.
Fixes: d7c088265588 ("net: socket: support hardware timestamp conversion to PHC bound")
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Yangbo Lu <yangbo.lu@nxp.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/net/socket.c b/net/socket.c
index 7f64a6e..5053eb0 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -829,6 +829,7 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
int empty = 1, false_tstamp = 0;
struct skb_shared_hwtstamps *shhwtstamps =
skb_hwtstamps(skb);
+ ktime_t hwtstamp;
/* Race occurred between timestamp enabling and packet
receiving. Fill in the current time for now. */
@@ -877,10 +878,12 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
(sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
!skb_is_swtx_tstamp(skb, false_tstamp)) {
if (sk->sk_tsflags & SOF_TIMESTAMPING_BIND_PHC)
- ptp_convert_timestamp(shhwtstamps, sk->sk_bind_phc);
+ hwtstamp = ptp_convert_timestamp(shhwtstamps,
+ sk->sk_bind_phc);
+ else
+ hwtstamp = shhwtstamps->hwtstamp;
- if (ktime_to_timespec64_cond(shhwtstamps->hwtstamp,
- tss.ts + 2)) {
+ if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) {
empty = 0;
if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&