diff options
| author | Christoph Paasch <cpaasch@apple.com> | 2020-05-14 08:53:03 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-05-16 13:51:10 -0700 |
| commit | a0c1d0eafd1ef1ada3b588ea205e5bc37ae0d8d9 (patch) | |
| tree | 9e6c4e1406a00559b1dd4ef04cf502d65e5cb3e7 /net/mptcp/protocol.h | |
| parent | 9efd6a3cecdde984d67e63d17fe6af53c7c50968 (diff) | |
mptcp: Use 32-bit DATA_ACK when possible
RFC8684 allows to send 32-bit DATA_ACKs as long as the peer is not
sending 64-bit data-sequence numbers. The 64-bit DSN is only there for
extreme scenarios when a very high throughput subflow is combined with a
long-RTT subflow such that the high-throughput subflow wraps around the
32-bit sequence number space within an RTT of the high-RTT subflow.
It is thus a rare scenario and we should try to use the 32-bit DATA_ACK
instead as long as possible. It allows to reduce the TCP-option overhead
by 4 bytes, thus makes space for an additional SACK-block. It also makes
tcpdumps much easier to read when the DSN and DATA_ACK are both either
32 or 64-bit.
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp/protocol.h')
| -rw-r--r-- | net/mptcp/protocol.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index e4ca6320ce76..f5adca93e8fb 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -290,6 +290,7 @@ struct mptcp_subflow_context { data_avail : 1, rx_eof : 1, data_fin_tx_enable : 1, + use_64bit_ack : 1, /* Set when we received a 64-bit DSN */ can_ack : 1; /* only after processing the remote a key */ u64 data_fin_tx_seq; u32 remote_nonce; |