5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Geliang Tang <geliang.tang@xxxxxxxx>
commit 0530020a7c8f2204e784f0dbdc882bbd961fdbde upstream.
This patch adds a new member allow_infinite_fallback in mptcp_sock,
which is initialized to 'true' when the connection begins and is set
to 'false' on any retransmit or successful MP_JOIN. Only do infinite
mapping fallback if there is a single subflow AND there have been no
retransmissions AND there have never been any MP_JOINs.
Suggested-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Geliang Tang <geliang.tang@xxxxxxxx>
Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: e32d262c89e2 ("mptcp: handle consistently DSS corruption")
[ Conflicts in protocol.c, because commit 3e5014909b56 ("mptcp: cleanup
MPJ subflow list handling") is not in this version. This commit is
linked to a new feature, changing the context around. The new line
can still be added at the same place.
Conflicts in protocol.h, because commit 4f6e14bd19d6 ("mptcp: support
TCP_CORK and TCP_NODELAY") is not in this version. This commit is
linked to a new feature, changing the context around. The new line can
still be added at the same place.
Conflicts in subflow.c, because commit 0348c690ed37 ("mptcp: add the
fallback check") is not in this version. This commit is linked to a
new feature, changing the context around. The new line can still be
added at the same place. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mptcp/protocol.c | 3 +++
net/mptcp/protocol.h | 1 +
net/mptcp/subflow.c | 4 +++-
3 files changed, 7 insertions(+), 1 deletion(-)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2472,6 +2472,7 @@ static void __mptcp_retrans(struct sock
dfrag->already_sent = max(dfrag->already_sent, info.sent);
tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
info.size_goal);
+ WRITE_ONCE(msk->allow_infinite_fallback, false);
}
release_sock(ssk);
@@ -2549,6 +2550,7 @@ static int __mptcp_init_sock(struct sock
msk->first = NULL;
inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
+ WRITE_ONCE(msk->allow_infinite_fallback, true);
msk->recovery = false;
mptcp_pm_data_init(msk);
@@ -3299,6 +3301,7 @@ bool mptcp_finish_join(struct sock *ssk)
if (parent_sock && !ssk->sk_socket)
mptcp_sock_graft(ssk, parent_sock);
subflow->map_seq = READ_ONCE(msk->ack_seq);
+ WRITE_ONCE(msk->allow_infinite_fallback, false);
out:
mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
return true;
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -249,6 +249,7 @@ struct mptcp_sock {
bool rcv_fastclose;
bool use_64bit_ack; /* Set when we received a 64-bit DSN */
bool csum_enabled;
+ bool allow_infinite_fallback;
spinlock_t join_list_lock;
int keepalive_cnt;
int keepalive_idle;
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1219,7 +1219,8 @@ no_data:
fallback:
/* RFC 8684 section 3.7. */
if (subflow->send_mp_fail) {
- if (mptcp_has_another_subflow(ssk)) {
+ if (mptcp_has_another_subflow(ssk) ||
+ !READ_ONCE(msk->allow_infinite_fallback)) {
while ((skb = skb_peek(&ssk->sk_receive_queue)))
sk_eat_skb(ssk, skb);
}
@@ -1481,6 +1482,7 @@ int __mptcp_subflow_connect(struct sock
/* discard the subflow socket */
mptcp_sock_graft(ssk, sk->sk_socket);
iput(SOCK_INODE(sf));
+ WRITE_ONCE(msk->allow_infinite_fallback, false);
return err;
failed_unlink:
