From: Geliang Tang tanggeliang@kylinos.cn

This patch adds "last time" fields last_data_sent, last_data_recv and last_ack_recv in struct mptcp_sock to record the last time data_sent, data_recv and ack_recv happened. They all are initialized as tcp_jiffies32 in __mptcp_init_sock(), and updated as tcp_jiffies32 too when data is sent in __subflow_push_pending(), data is received in __mptcp_move_skbs_from_subflow(), and ack is received in ack_update_msk().

Similar to tcpi_last_data_sent, tcpi_last_data_recv and tcpi_last_ack_recv exposed with TCP, this patch exposes the last time "an action happened" for MPTCP in mptcp_info, named mptcpi_last_data_sent, mptcpi_last_data_recv and mptcpi_last_ack_recv, calculated in mptcp_diag_fill_info() as the time deltas between now and the newly added last time fields in mptcp_sock.

Since msk->last_ack_recv needs to be protected by mptcp_data_lock/unlock, and lock_sock_fast can sleep and be quite slow, move the entire mptcp_data_lock/unlock block after the lock/unlock_sock_fast block. Then mptcpi_last_data_sent and mptcpi_last_data_recv are set in lock/unlock_sock_fast block, while mptcpi_last_ack_recv is set in mptcp_data_lock/unlock block, which is protected by a spinlock and should not block for too long.

Also add three reserved bytes in struct mptcp_info not to have holes in this structure exposed to userspace.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/446 Signed-off-by: Geliang Tang tanggeliang@kylinos.cn Reviewed-by: Mat Martineau martineau@kernel.org Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- v2: - Set 'now = jiffies32' inside '(un)lock_sock_fast' block (Eric). - Move 'mptcp_data_(un)lock' block after '(un)lock_sock_fast', not to reload 'now', and have all counters synced (Matthieu / Mat). --- include/uapi/linux/mptcp.h | 4 ++++ net/mptcp/options.c | 1 + net/mptcp/protocol.c | 7 +++++++ net/mptcp/protocol.h | 3 +++ net/mptcp/sockopt.c | 16 +++++++++++----- 5 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h index 74cfe496891e..67d015df8893 100644 --- a/include/uapi/linux/mptcp.h +++ b/include/uapi/linux/mptcp.h @@ -58,6 +58,10 @@ struct mptcp_info { __u64 mptcpi_bytes_received; __u64 mptcpi_bytes_acked; __u8 mptcpi_subflows_total; + __u8 reserved[3]; + __u32 mptcpi_last_data_sent; + __u32 mptcpi_last_data_recv; + __u32 mptcpi_last_ack_recv; };

/* MPTCP Reset reason codes, rfc8684 */ diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 27ca42c77b02..8e8dcfbc2993 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -1068,6 +1068,7 @@ static void ack_update_msk(struct mptcp_sock *msk, __mptcp_snd_una_update(msk, new_snd_una); __mptcp_data_acked(sk); } + msk->last_ack_recv = tcp_jiffies32; mptcp_data_unlock(sk);

trace_ack_update_msk(mp_opt->data_ack, diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 995b53cd021c..f8bc34f0d973 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -706,6 +706,8 @@ static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, } } while (more_data_avail);

+ if (moved > 0) + msk->last_data_recv = tcp_jiffies32; *bytes += moved; return done; } @@ -1556,6 +1558,8 @@ static int __subflow_push_pending(struct sock *sk, struct sock *ssk, err = copied;

out: + if (err > 0) + msk->last_data_sent = tcp_jiffies32; return err; }

@@ -2793,6 +2797,9 @@ static void __mptcp_init_sock(struct sock *sk) WRITE_ONCE(msk->allow_infinite_fallback, true); msk->recovery = false; msk->subflow_id = 1; + msk->last_data_sent = tcp_jiffies32; + msk->last_data_recv = tcp_jiffies32; + msk->last_ack_recv = tcp_jiffies32;

mptcp_pm_data_init(msk);

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 46f4655b7123..fdfa843e2d88 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -282,6 +282,9 @@ struct mptcp_sock { u64 bytes_acked; u64 snd_una; u64 wnd_end; + u32 last_data_sent; + u32 last_data_recv; + u32 last_ack_recv; unsigned long timer_ival; u32 token; int rmem_released; diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 9d5d42a77bcc..1fea43f5b6f3 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -898,6 +898,7 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) struct sock *sk = (struct sock *)msk; u32 flags = 0; bool slow; + u32 now;

memset(info, 0, sizeof(*info));

@@ -926,11 +927,6 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) if (READ_ONCE(msk->can_ack)) flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED; info->mptcpi_flags = flags; - mptcp_data_lock(sk); - info->mptcpi_snd_una = msk->snd_una; - info->mptcpi_rcv_nxt = msk->ack_seq; - info->mptcpi_bytes_acked = msk->bytes_acked; - mptcp_data_unlock(sk);

slow = lock_sock_fast(sk); info->mptcpi_csum_enabled = READ_ONCE(msk->csum_enabled); @@ -942,7 +938,17 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) info->mptcpi_bytes_retrans = msk->bytes_retrans; info->mptcpi_subflows_total = info->mptcpi_subflows + __mptcp_has_initial_subflow(msk); + now = tcp_jiffies32; + info->mptcpi_last_data_sent = jiffies_to_msecs(now - msk->last_data_sent); + info->mptcpi_last_data_recv = jiffies_to_msecs(now - msk->last_data_recv); unlock_sock_fast(sk, slow); + + mptcp_data_lock(sk); + info->mptcpi_last_ack_recv = jiffies_to_msecs(now - msk->last_ack_recv); + info->mptcpi_snd_una = msk->snd_una; + info->mptcpi_rcv_nxt = msk->ack_seq; + info->mptcpi_bytes_acked = msk->bytes_acked; + mptcp_data_unlock(sk); } EXPORT_SYMBOL_GPL(mptcp_diag_fill_info);