From fa3fe2b150316b294f2c662653501273ff25bba8 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 19 Nov 2020 11:46:02 -0800 Subject: mptcp: track window announced to peer OoO handling attempts to detect when packet is out-of-window by testing current ack sequence and remaining space vs. sequence number. This doesn't work reliably. Store the highest allowed sequence number that we've announced and use it to detect oow packets. Do this when mptcp options get written to the packet (wire format). For this to work we need to move the write_options call until after stack selected a new tcp window. Acked-by: Paolo Abeni Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- net/mptcp/protocol.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'net/mptcp/protocol.c') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8f303de7f500..e1606e072218 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -168,19 +168,19 @@ static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb) struct rb_node **p, *parent; u64 seq, end_seq, max_seq; struct sk_buff *skb1; - int space; seq = MPTCP_SKB_CB(skb)->map_seq; end_seq = MPTCP_SKB_CB(skb)->end_seq; - space = tcp_space(sk); - max_seq = space > 0 ? space + msk->ack_seq : msk->ack_seq; + max_seq = READ_ONCE(msk->rcv_wnd_sent); pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq, RB_EMPTY_ROOT(&msk->out_of_order_queue)); - if (after64(seq, max_seq)) { + if (after64(end_seq, max_seq)) { /* out of window */ mptcp_drop(sk, skb); - pr_debug("oow by %ld", (unsigned long)seq - (unsigned long)max_seq); + pr_debug("oow by %lld, rcv_wnd_sent %llu\n", + (unsigned long long)end_seq - (unsigned long)max_seq, + (unsigned long long)msk->rcv_wnd_sent); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW); return; } @@ -2295,6 +2295,7 @@ struct sock *mptcp_sk_clone(const struct sock *sk, mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); ack_seq++; WRITE_ONCE(msk->ack_seq, ack_seq); + WRITE_ONCE(msk->rcv_wnd_sent, ack_seq); } sock_reset_flag(nsk, SOCK_RCU_FREE); @@ -2587,6 +2588,7 @@ void mptcp_finish_connect(struct sock *ssk) WRITE_ONCE(msk->write_seq, subflow->idsn + 1); WRITE_ONCE(msk->snd_nxt, msk->write_seq); WRITE_ONCE(msk->ack_seq, ack_seq); + WRITE_ONCE(msk->rcv_wnd_sent, ack_seq); WRITE_ONCE(msk->can_ack, 1); atomic64_set(&msk->snd_una, msk->write_seq); -- cgit v1.2.3