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 <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 99905bc..41880d3 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -445,11 +445,12 @@ struct tcp_out_options {
struct mptcp_out_options mptcp;
};
-static void mptcp_options_write(__be32 *ptr, struct tcp_out_options *opts)
+static void mptcp_options_write(__be32 *ptr, const struct tcp_sock *tp,
+ struct tcp_out_options *opts)
{
#if IS_ENABLED(CONFIG_MPTCP)
if (unlikely(OPTION_MPTCP & opts->options))
- mptcp_write_options(ptr, &opts->mptcp);
+ mptcp_write_options(ptr, tp, &opts->mptcp);
#endif
}
@@ -701,7 +702,7 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
smc_options_write(ptr, &options);
- mptcp_options_write(ptr, opts);
+ mptcp_options_write(ptr, tp, opts);
}
static void smc_set_option(const struct tcp_sock *tp,
@@ -1346,7 +1347,6 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
}
}
- tcp_options_write((__be32 *)(th + 1), tp, &opts);
skb_shinfo(skb)->gso_type = sk->sk_gso_type;
if (likely(!(tcb->tcp_flags & TCPHDR_SYN))) {
th->window = htons(tcp_select_window(sk));
@@ -1357,6 +1357,9 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
*/
th->window = htons(min(tp->rcv_wnd, 65535U));
}
+
+ tcp_options_write((__be32 *)(th + 1), tp, &opts);
+
#ifdef CONFIG_TCP_MD5SIG
/* Calculate the MD5 hash, as we have all we need now */
if (md5) {