From: Paolo Abeni <[email protected]>
Sashiko noted that retransmission with csum enabled can actually
transmit new data, but currently the relevant code does not update
accordingly snd_nxt.
The may cause incoming ack drop and an endless retransmission loop.
Address the issue incrementing snd_nxt as needed.
Fixes: 4e14867d5e91 ("mptcp: tune re-injections for csum enabled mode")
Cc: [email protected]
Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Matthieu Baerts (NGI0) <[email protected]>
Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>
---
net/mptcp/protocol.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 5a20ab2789ae..7fac5fac2097 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2869,6 +2869,10 @@ static void __mptcp_retrans(struct sock *sk)
msk->bytes_retrans += len;
dfrag->already_sent = max(dfrag->already_sent, len);
+ /* With csum enabled retransmission can send new data. */
+ if (after64(dfrag->already_sent + dfrag->data_seq, msk->snd_nxt))
+ WRITE_ONCE(msk->snd_nxt, dfrag->already_sent + dfrag->data_seq);
+
reset_timer:
mptcp_check_and_set_pending(sk);
--
2.53.0
