mptcp: add CurrEstab MIB counter support

Add a new MIB counter named MPTCP_MIB_CURRESTAB to count current
established MPTCP connections, similar to TCP_MIB_CURRESTAB. This is
useful to quickly list the number of MPTCP connections without having to
iterate over all of them.

This patch adds a new helper function mptcp_set_state(): if the state
switches from or to ESTABLISHED state, this newly added counter is
incremented. This helper is going to be used in the following patch.

Similar to MPTCP_INC_STATS(), a new helper called MPTCP_DEC_STATS() is
also needed to decrement a MIB counter.

Signed-off-by: Geliang Tang <geliang.tang@linux.dev>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: introduces more address related mibs

Currently we don't track explicitly a few events related to address
management suboption handling; this patch adds new mibs for ADD_ADDR
and RM_ADDR options tx and for missed tx events due to internal storage
exhaustion.

The self-tests must be updated to properly handle different mibs with
the same/shared prefix.

Additionally removes a couple of warning tracking the loss event.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/378
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add more offered MIBs counter

Track the exceptional handling of MPTCP-level offered window
with a few more counters for observability.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add mib for xmit window sharing

Bump a counter for counter when snd_wnd is shared among subflow,
for observability's sake.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add mib for infinite map sending

This patch adds a new mib named MPTCP_MIB_INFINITEMAPTX, increase it
when a infinite mapping has been sent out.

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>

mptcp: add the mibs for MP_RST

This patch added two more mibs for MP_RST, MPTCP_MIB_MPRSTTX for
the MP_RST sending and MPTCP_MIB_MPRSTRX for the MP_RST receiving.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add the mibs for MP_FASTCLOSE

This patch added two more mibs for MP_FASTCLOSE, MPTCP_MIB_MPFASTCLOSETX
for the MP_FASTCLOSE sending and MPTCP_MIB_MPFASTCLOSERX for receiving.

Also added a debug log for MP_FASTCLOSE receiving, printed out the recv_key
of MP_FASTCLOSE in mptcp_parse_option to show that MP_RST is received.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add mibs counter for ignored incoming options

The MPTCP in kernel path manager has some constraints on incoming
addresses announce processing, so that in edge scenarios it can
end-up dropping (ignoring) some of such announces.

The above is not very limiting in practice since such scenarios are
very uncommon and MPTCP will recover due to ADD_ADDR retransmissions.

This patch adds a few MIB counters to account for such drop events
to allow easier introspection of the critical scenarios.

Fixes: f7efc7771eac ("mptcp: drop argument port from mptcp_pm_announce_addr")
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: use batch snmp operations in mptcp_seq_show()

Using snmp_get_cpu_field_batch() allows for better cpu cache
utilization, especially on hosts with large number of cpus.

Also remove special handling when mptcp mibs where not yet
allocated.

I chose to use temporary storage on the stack to keep this patch simple.
We might in the future use the storage allocated in netstat_seq_show().

Combined with prior patch (inlining snmp_get_cpu_field)
time to fetch and output mptcp counters on a 256 cpu host [1]
goes from 75 usec to 16 usec.

[1] L1 cache size is 32KB, it is not big enough to hold all dataset.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add the mibs for MP_FAIL

This patch added the mibs for MP_FAIL: MPTCP_MIB_MPFAILTX and
MPTCP_MIB_MPFAILRX.

Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add mibs for stale subflows processing

This allows monitoring exceptional events like
active backup scenarios.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: properly account bulk freed memory

After commit 879526030c8b ("mptcp: protect the rx path with
the msk socket spinlock") the rmem currently used by a given
msk is really sk_rmem_alloc - rmem_released.

The safety check in mptcp_data_ready() does not take the above
in due account, as a result legit incoming data is kept in
subflow receive queue with no reason, delaying or blocking
MPTCP-level ack generation.

This change addresses the issue introducing a new helper to fetch
the rmem memory and using it as needed. Additionally add a MIB
counter for the exceptional event described above - the peer is
misbehaving.

Finally, introduce the required annotation when rmem_released is
updated.

Fixes: 879526030c8b ("mptcp: protect the rx path with the msk socket spinlock")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/211
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add MIB counter for invalid mapping

Account this exceptional events for better introspection.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add the mib for data checksum

This patch added the mib for the data checksum, MPTCP_MIB_DATACSUMERR.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add active MPC mibs

We are not currently tracking the active MPTCP connection
attempts. Let's add the related counters.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add mib for token creation fallback

If the MPTCP protocol is unable to create a new token,
the socket fallback to plain TCP, let's keep track
of such events via a specific MIB.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add the mibs for ADD_ADDR with port

This patch adds the mibs for ADD_ADDR with port:

MPTCP_MIB_PORTADD for received ADD_ADDR suboption with a port number.

MPTCP_MIB_PORTSYNRX, MPTCP_MIB_PORTSYNACKRX, MPTCP_MIB_PORTACKRX, for
received MP_JOIN's SYN or SYN/ACK or ACK with a port number which is
different from the msk's port number.

MPTCP_MIB_MISMATCHPORTSYNRX and MPTCP_MIB_MISMATCHPORTACKRX, for
received SYN or ACK MP_JOIN with a mismatched port-number.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add the mibs for MP_PRIO

This patch added the mibs for MP_PRIO, MPTCP_MIB_MPPRIOTX for transmitting
of the MP_PRIO suboption, and MPTCP_MIB_MPPRIORX for receiving of it.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: print new line in mptcp_seq_show() if mptcp isn't in use

When do cat /proc/net/netstat, the output isn't append with a new line, it looks like this:
[root@localhost ~]# cat /proc/net/netstat
...
MPTcpExt: 0 0 0 0 0 0 0 0 0 0 0 0 0[root@localhost ~]#

This is because in mptcp_seq_show(), if mptcp isn't in use, net->mib.mptcp_statistics is NULL,
so it just puts all 0 after "MPTcpExt:", and return, forgot the '\n'.

After this patch:

[root@localhost ~]# cat /proc/net/netstat
...
MPTcpExt: 0 0 0 0 0 0 0 0 0 0 0 0 0
[root@localhost ~]#

Fixes: fc518953bc9c8d7d ("mptcp: add and use MIB counter infrastructure")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Acked-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/142e2fd9-58d9-bb13-fb75-951cccc2331e@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mptcp: add RM_ADDR related mibs

This patch added two new mibs for RM_ADDR, named MPTCP_MIB_RMADDR and
MPTCP_MIB_RMSUBFLOW, when the RM_ADDR suboption is received, increase
the first mib counter, when the local subflow is removed, increase the
second mib counter.

Suggested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add ADD_ADDR related mibs

This patch added two mibs for ADD_ADDR, MPTCP_MIB_ADDADDR for receiving
of the ADD_ADDR suboption with echo-flag=0, and MPTCP_MIB_ECHOADD for
receiving the ADD_ADDR suboption with echo-flag=1.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add OoO related mibs

Add a bunch of MPTCP mibs related to MPTCP OoO data
processing.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mptcp: add and use MIB counter infrastructure

Exported via same /proc file as the Linux TCP MIB counters, so "netstat -s"
or "nstat" will show them automatically.

The MPTCP MIB counters are allocated in a distinct pcpu area in order to
avoid bloating/wasting TCP pcpu memory.

Counters are allocated once the first MPTCP socket is created in a
network namespace and free'd on exit.

If no sockets have been allocated, all-zero mptcp counters are shown.

The MIB counter list is taken from the multipath-tcp.org kernel, but
only a few counters have been picked up so far. The counter list can
be increased at any time later on.

v2 -> v3:
- remove 'inline' in foo.c files (David S. Miller)

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>