From: Geliang Tang geliang.tang@suse.com
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@redhat.com Signed-off-by: Geliang Tang geliang.tang@suse.com Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net 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@kernel.org --- net/mptcp/protocol.c | 3 +++ net/mptcp/protocol.h | 1 + net/mptcp/subflow.c | 4 +++- 3 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index da2a1a150bc6..73a0b0d15382 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2472,6 +2472,7 @@ static void __mptcp_retrans(struct sock *sk) 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 *sk) 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; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 9e0a5591d4e1..5d458c3161cd 100644 --- 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; diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index e71082dd6484..412823af2c1d 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1219,7 +1219,8 @@ static bool subflow_check_data_avail(struct sock *ssk) 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 *sk, const struct mptcp_addr_info *loc, /* 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: