diff options
| author | Dmytro Shytyi <dmytro@shytyi.net> | 2022-11-25 23:29:51 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-11-29 20:24:25 -0800 |
| commit | 36b122baf6a8bd46b4a591f12f4ed17b22257408 (patch) | |
| tree | ec7cb63c0adeacab7199cac9c0722899543686e1 /net/mptcp/fastopen.c | |
| parent | dfc8d06030335a816d81aa92fe5d1f84d06998ad (diff) | |
mptcp: add subflow_v(4,6)_send_synack()
The send_synack() needs to be overridden for MPTCP to support TFO for
two reasons:
- There is not be enough space in the TCP options if the TFO cookie has
to be added in the SYN+ACK with other options: MSS (4), SACK OK (2),
Timestamps (10), Window Scale (3+1), TFO (10+2), MP_CAPABLE (12).
MPTCPv1 specs -- RFC 8684, section B.1 [1] -- suggest to drop the TCP
timestamps option in this case.
- The data received in the SYN has to be handled: the SKB can be
dequeued from the subflow sk and transferred to the MPTCP sk. Counters
need to be updated accordingly and the application can be notified at
the end because some bytes have been received.
[1] https://www.rfc-editor.org/rfc/rfc8684.html#section-b.1
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Dmytro Shytyi <dmytro@shytyi.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/mptcp/fastopen.c')
| -rw-r--r-- | net/mptcp/fastopen.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/net/mptcp/fastopen.c b/net/mptcp/fastopen.c index 19c332af0834..d237d142171c 100644 --- a/net/mptcp/fastopen.c +++ b/net/mptcp/fastopen.c @@ -6,6 +6,51 @@ #include "protocol.h" +void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow, + struct request_sock *req) +{ + struct sock *ssk = subflow->tcp_sock; + struct sock *sk = subflow->conn; + struct sk_buff *skb; + struct tcp_sock *tp; + + tp = tcp_sk(ssk); + + subflow->is_mptfo = 1; + + skb = skb_peek(&ssk->sk_receive_queue); + if (WARN_ON_ONCE(!skb)) + return; + + /* dequeue the skb from sk receive queue */ + __skb_unlink(skb, &ssk->sk_receive_queue); + skb_ext_reset(skb); + skb_orphan(skb); + + /* We copy the fastopen data, but that don't belong to the mptcp sequence + * space, need to offset it in the subflow sequence, see mptcp_subflow_get_map_offset() + */ + tp->copied_seq += skb->len; + subflow->ssn_offset += skb->len; + + /* initialize a dummy sequence number, we will update it at MPC + * completion, if needed + */ + MPTCP_SKB_CB(skb)->map_seq = -skb->len; + MPTCP_SKB_CB(skb)->end_seq = 0; + MPTCP_SKB_CB(skb)->offset = 0; + MPTCP_SKB_CB(skb)->has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp; + + mptcp_data_lock(sk); + + mptcp_set_owner_r(skb, sk); + __skb_queue_tail(&sk->sk_receive_queue, skb); + + sk->sk_data_ready(sk); + + mptcp_data_unlock(sk); +} + void mptcp_fastopen_gen_msk_ackseq(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow, const struct mptcp_options_received *mp_opt) { |