rxrpc: Preset timestamp on Tx sk_buffs
Set the timestamp on sk_buffs holding packets to be transmitted before
queueing them because the moment the packet is on the queue it can be seen
by the retransmission algorithm - which may see a completely random
timestamp.
If the retransmission algorithm sees such a timestamp, it may retransmit
the packet and, in future, tell the congestion management algorithm that
the retransmit timer expired.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index ca7c3be..ca3811b 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -99,6 +99,11 @@
ASSERTCMP(seq, ==, call->tx_top + 1);
+ /* We have to set the timestamp before queueing as the retransmit
+ * algorithm can see the packet as soon as we queue it.
+ */
+ skb->tstamp = ktime_get_real();
+
ix = seq & RXRPC_RXTX_BUFF_MASK;
rxrpc_get_skb(skb, rxrpc_skb_tx_got);
call->rxtx_annotations[ix] = RXRPC_TX_ANNO_UNACK;