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Diffstat (limited to 'net/socket.c')
-rw-r--r--net/socket.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/net/socket.c b/net/socket.c
index 67db7d8a3b81..cb355a7ef135 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -662,6 +662,19 @@ static bool skb_is_err_queue(const struct sk_buff *skb)
return skb->pkt_type == PACKET_OUTGOING;
}
+/* On transmit, software and hardware timestamps are returned independently.
+ * As the two skb clones share the hardware timestamp, which may be updated
+ * before the software timestamp is received, a hardware TX timestamp may be
+ * returned only if there is no software TX timestamp. Ignore false software
+ * timestamps, which may be made in the __sock_recv_timestamp() call when the
+ * option SO_TIMESTAMP(NS) is enabled on the socket, even when the skb has a
+ * hardware timestamp.
+ */
+static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
+{
+ return skb->tstamp && !false_tstamp && skb_is_err_queue(skb);
+}
+
static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb)
{
struct scm_ts_pktinfo ts_pktinfo;
@@ -691,14 +704,16 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
{
int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
struct scm_timestamping tss;
- int empty = 1;
+ int empty = 1, false_tstamp = 0;
struct skb_shared_hwtstamps *shhwtstamps =
skb_hwtstamps(skb);
/* Race occurred between timestamp enabling and packet
receiving. Fill in the current time for now. */
- if (need_software_tstamp && skb->tstamp == 0)
+ if (need_software_tstamp && skb->tstamp == 0) {
__net_timestamp(skb);
+ false_tstamp = 1;
+ }
if (need_software_tstamp) {
if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
@@ -720,6 +735,7 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
empty = 0;
if (shhwtstamps &&
(sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
+ !skb_is_swtx_tstamp(skb, false_tstamp) &&
ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2)) {
empty = 0;
if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&