From 59832e246515ab6a4f5aa878073e6f415aa35166 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 2 Apr 2020 13:44:52 +0200 Subject: [PATCH] mptcp: subflow: check parent mptcp socket on subflow state change This is needed at least until proper MPTCP-Level fin/reset signalling gets added: We wake parent when a subflow changes, but we should do this only when all subflows have closed, not just one. Schedule the mptcp worker and tell it to check eof state on all subflows. Only flag mptcp socket as closed and wake userspace processes blocking in poll if all subflows have closed. Co-developed-by: Paolo Abeni Signed-off-by: Paolo Abeni Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 33 +++++++++++++++++++++++++++++++++ net/mptcp/protocol.h | 2 ++ net/mptcp/subflow.c | 3 +-- 3 files changed, 36 insertions(+), 2 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 4cf88e3d5121..8cc9dd2cc828 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -327,6 +327,15 @@ void mptcp_data_acked(struct sock *sk) sock_hold(sk); } +void mptcp_subflow_eof(struct sock *sk) +{ + struct mptcp_sock *msk = mptcp_sk(sk); + + if (!test_and_set_bit(MPTCP_WORK_EOF, &msk->flags) && + schedule_work(&msk->work)) + sock_hold(sk); +} + static void mptcp_stop_timer(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); @@ -1031,6 +1040,27 @@ static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) return 0; } +static void mptcp_check_for_eof(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + struct sock *sk = (struct sock *)msk; + int receivers = 0; + + mptcp_for_each_subflow(msk, subflow) + receivers += !subflow->rx_eof; + + if (!receivers && !(sk->sk_shutdown & RCV_SHUTDOWN)) { + /* hopefully temporary hack: propagate shutdown status + * to msk, when all subflows agree on it + */ + sk->sk_shutdown |= RCV_SHUTDOWN; + + smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ + set_bit(MPTCP_DATA_READY, &msk->flags); + sk->sk_data_ready(sk); + } +} + static void mptcp_worker(struct work_struct *work) { struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); @@ -1047,6 +1077,9 @@ static void mptcp_worker(struct work_struct *work) __mptcp_flush_join_list(msk); __mptcp_move_skbs(msk); + if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags)) + mptcp_check_for_eof(msk); + if (!test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) goto unlock; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index f733c5425552..67448002a2d7 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -89,6 +89,7 @@ #define MPTCP_DATA_READY 0 #define MPTCP_SEND_SPACE 1 #define MPTCP_WORK_RTX 2 +#define MPTCP_WORK_EOF 3 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field) { @@ -339,6 +340,7 @@ void mptcp_finish_connect(struct sock *sk); void mptcp_data_ready(struct sock *sk, struct sock *ssk); bool mptcp_finish_join(struct sock *sk); void mptcp_data_acked(struct sock *sk); +void mptcp_subflow_eof(struct sock *sk); int mptcp_token_new_request(struct request_sock *req); void mptcp_token_destroy_request(u32 token); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index b5180c81588e..50a8bea987c6 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -994,8 +994,7 @@ static void subflow_state_change(struct sock *sk) if (!(parent->sk_shutdown & RCV_SHUTDOWN) && !subflow->rx_eof && subflow_is_done(sk)) { subflow->rx_eof = 1; - parent->sk_shutdown |= RCV_SHUTDOWN; - __subflow_state_change(parent); + mptcp_subflow_eof(parent); } } -- GitLab