On Tue, Jun 20, 2023 at 6:30 PM Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx> wrote: > > From: Paolo Abeni <pabeni@xxxxxxxxxx> > > Currently there are no data transfer counters accounting for all > the subflows used by a given MPTCP socket. The user-space can compute > such figures aggregating the subflow info, but that is inaccurate > if any subflow is closed before the MPTCP socket itself. > > Add the new counters in the MPTCP socket itself and expose them > via the existing diag and sockopt. While touching mptcp_diag_fill_info(), > acquire the relevant locks before fetching the msk data, to ensure > better data consistency > > Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/385 > Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> > Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx> > Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx> > --- > include/uapi/linux/mptcp.h | 5 +++++ > net/mptcp/options.c | 10 ++++++++-- > net/mptcp/protocol.c | 11 ++++++++++- > net/mptcp/protocol.h | 4 ++++ > net/mptcp/sockopt.c | 25 ++++++++++++++++++++----- > 5 files changed, 47 insertions(+), 8 deletions(-) > > diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h > index 32af2d278cb4..a124be6ebbba 100644 > --- a/include/uapi/linux/mptcp.h > +++ b/include/uapi/linux/mptcp.h > @@ -123,6 +123,11 @@ struct mptcp_info { > __u8 mptcpi_local_addr_used; > __u8 mptcpi_local_addr_max; > __u8 mptcpi_csum_enabled; > + __u32 mptcpi_retransmits; > + __u64 mptcpi_bytes_retrans; > + __u64 mptcpi_bytes_sent; > + __u64 mptcpi_bytes_received; > + __u64 mptcpi_bytes_acked; > }; > > /* > diff --git a/net/mptcp/options.c b/net/mptcp/options.c > index 4bdcd2b326bd..c254accb14de 100644 > --- a/net/mptcp/options.c > +++ b/net/mptcp/options.c > @@ -1026,6 +1026,12 @@ u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq) > return cur_seq; > } > > +static void __mptcp_snd_una_update(struct mptcp_sock *msk, u64 new_snd_una) > +{ > + msk->bytes_acked += new_snd_una - msk->snd_una; > + msk->snd_una = new_snd_una; > +} > + > static void ack_update_msk(struct mptcp_sock *msk, > struct sock *ssk, > struct mptcp_options_received *mp_opt) > @@ -1057,7 +1063,7 @@ static void ack_update_msk(struct mptcp_sock *msk, > __mptcp_check_push(sk, ssk); > > if (after64(new_snd_una, old_snd_una)) { > - msk->snd_una = new_snd_una; > + __mptcp_snd_una_update(msk, new_snd_una); > __mptcp_data_acked(sk); > } > mptcp_data_unlock(sk); > @@ -1123,7 +1129,7 @@ bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > /* on fallback we just need to ignore the msk-level snd_una, as > * this is really plain TCP > */ > - msk->snd_una = READ_ONCE(msk->snd_nxt); > + __mptcp_snd_una_update(msk, READ_ONCE(msk->snd_nxt)); > > __mptcp_data_acked(subflow->conn); > mptcp_data_unlock(subflow->conn); > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index 9c756d675d4d..d5b8e488bce1 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -377,6 +377,7 @@ static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, > > if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) { > /* in sequence */ > + msk->bytes_received += copy_len; > WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len); > tail = skb_peek_tail(&sk->sk_receive_queue); > if (tail && mptcp_try_coalesce(sk, tail, skb)) > @@ -760,6 +761,7 @@ static bool __mptcp_ofo_queue(struct mptcp_sock *msk) > MPTCP_SKB_CB(skb)->map_seq += delta; > __skb_queue_tail(&sk->sk_receive_queue, skb); > } > + msk->bytes_received += end_seq - msk->ack_seq; > msk->ack_seq = end_seq; > moved = true; > } > @@ -1531,8 +1533,10 @@ static void mptcp_update_post_push(struct mptcp_sock *msk, > * that has been handed to the subflow for transmission > * and skip update in case it was old dfrag. > */ > - if (likely(after64(snd_nxt_new, msk->snd_nxt))) > + if (likely(after64(snd_nxt_new, msk->snd_nxt))) { > + msk->bytes_sent += snd_nxt_new - msk->snd_nxt; > msk->snd_nxt = snd_nxt_new; > + } > } > > void mptcp_check_and_set_pending(struct sock *sk) > @@ -2590,6 +2594,7 @@ static void __mptcp_retrans(struct sock *sk) > } > if (copied) { > dfrag->already_sent = max(dfrag->already_sent, info.sent); > + msk->bytes_retrans += copied; > tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle, > info.size_goal); > WRITE_ONCE(msk->allow_infinite_fallback, false); > @@ -3102,6 +3107,10 @@ static int mptcp_disconnect(struct sock *sk, int flags) > WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk))); > mptcp_pm_data_reset(msk); > mptcp_ca_reset(sk); > + msk->bytes_acked = 0; > + msk->bytes_received = 0; > + msk->bytes_sent = 0; > + msk->bytes_retrans = 0; > > WRITE_ONCE(sk->sk_shutdown, 0); > sk_error_report(sk); > diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h > index 47b46602870e..27adfcc5aaa2 100644 > --- a/net/mptcp/protocol.h > +++ b/net/mptcp/protocol.h > @@ -262,10 +262,13 @@ struct mptcp_sock { > u64 local_key; > u64 remote_key; > u64 write_seq; > + u64 bytes_sent; > u64 snd_nxt; > + u64 bytes_received; > u64 ack_seq; > atomic64_t rcv_wnd_sent; > u64 rcv_data_fin_seq; > + u64 bytes_retrans; > int rmem_fwd_alloc; > struct sock *last_snd; > int snd_burst; > @@ -274,6 +277,7 @@ struct mptcp_sock { > * recovery related fields are under data_lock > * protection > */ > + u64 bytes_acked; > u64 snd_una; > u64 wnd_end; > unsigned long timer_ival; > diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c > index e172a5848b0d..fa5055d5b029 100644 > --- a/net/mptcp/sockopt.c > +++ b/net/mptcp/sockopt.c > @@ -889,7 +889,9 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int > > void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) > { > + struct sock *sk = (struct sock *)msk; > u32 flags = 0; > + bool slow; > > memset(info, 0, sizeof(*info)); > > @@ -898,6 +900,9 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) > info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted); > info->mptcpi_local_addr_used = READ_ONCE(msk->pm.local_addr_used); > > + if (inet_sk_state_load(sk) == TCP_LISTEN) > + return; > + > /* The following limits only make sense for the in-kernel PM */ > if (mptcp_pm_is_kernel(msk)) { > info->mptcpi_subflows_max = > @@ -915,11 +920,21 @@ 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; > - info->mptcpi_token = READ_ONCE(msk->token); > - info->mptcpi_write_seq = READ_ONCE(msk->write_seq); > - info->mptcpi_snd_una = READ_ONCE(msk->snd_una); > - info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq); > - info->mptcpi_csum_enabled = READ_ONCE(msk->csum_enabled); > + 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); This causes a lockdep issue. lock_sock_fast(sk) could sleep, if socket lock is owned by another process. But we are called from a context where both a spin lock and rcu_read_lock() are held. BUG: sleeping function called from invalid context at net/core/sock.c:3549 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 316, name: syz-executor.4 preempt_count: 1, expected: 0 RCU nest depth: 1, expected: 0 7 locks held by syz-executor.4/316: #0: ffffffff8e125408 (sock_diag_mutex){+.+.}-{3:3}, at: sock_diag_rcv+0x1b/0x40 net/core/sock_diag.c:279 #1: ffffffff8e125588 (sock_diag_table_mutex){+.+.}-{3:3}, at: sock_diag_rcv_msg net/core/sock_diag.c:259 [inline] #1: ffffffff8e125588 (sock_diag_table_mutex){+.+.}-{3:3}, at: sock_diag_rcv_msg+0x2d2/0x440 net/core/sock_diag.c:248 #2: ffff8880232bb688 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{3:3}, at: netlink_dump+0xbe/0xc50 net/netlink/af_netlink.c:2215 #3: ffffffff8e29a628 (inet_diag_table_mutex){+.+.}-{3:3}, at: inet_diag_lock_handler+0x6e/0x100 net/ipv4/inet_diag.c:63 #4: ffffffff8c7990c0 (rcu_read_lock){....}-{1:2}, at: mptcp_diag_dump_listeners net/mptcp/mptcp_diag.c:95 [inline] #4: ffffffff8c7990c0 (rcu_read_lock){....}-{1:2}, at: mptcp_diag_dump+0x7c8/0x1330 net/mptcp/mptcp_diag.c:197 #5: ffffc90001316bf0 (&h->lhash2[i].lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] #5: ffffc90001316bf0 (&h->lhash2[i].lock){+.+.}-{2:2}, at: mptcp_diag_dump_listeners net/mptcp/mptcp_diag.c:98 [inline] #5: ffffc90001316bf0 (&h->lhash2[i].lock){+.+.}-{2:2}, at: mptcp_diag_dump+0x838/0x1330 net/mptcp/mptcp_diag.c:197 #6: ffff88802c42a5f0 (msk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_diag_get_info+0x1ae/0x380 net/mptcp/mptcp_diag.c:224 Preemption disabled at: [<0000000000000000>] 0x0 > + info->mptcpi_csum_enabled = msk->csum_enabled; > + info->mptcpi_token = msk->token; > + info->mptcpi_write_seq = msk->write_seq; > + info->mptcpi_retransmits = inet_csk(sk)->icsk_retransmits; > + info->mptcpi_bytes_sent = msk->bytes_sent; > + info->mptcpi_bytes_received = msk->bytes_received; > + info->mptcpi_bytes_retrans = msk->bytes_retrans; > + unlock_sock_fast(sk, slow); > } > EXPORT_SYMBOL_GPL(mptcp_diag_fill_info); > > > -- > 2.40.1 >
