[PATCH 6.6 120/299] mptcp: add CurrEstab MIB counter support

Greg Kroah-Hartman
2024-02-27T13:52:14Z

From: Geliang Tang <geliang.tang@linux.dev>

[ Upstream commit d9cd27b8cd191133e287e5de107f971136abe8a2 ]

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>
Stable-dep-of: e4a0fa47e816 ("mptcp: corner case locking for rx path fields initialization")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mptcp/mib.c | 1 +
net/mptcp/mib.h | 8 ++++++++
net/mptcp/protocol.c | 18 ++++++++++++++++++
net/mptcp/protocol.h | 1 +
4 files changed, 28 insertions(+)

diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index a0990c365a2ea..c30405e768337 100644
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -66,6 +66,7 @@ static const struct snmp_mib mptcp_snmp_list[] = {
SNMP_MIB_ITEM("RcvWndShared", MPTCP_MIB_RCVWNDSHARED),
SNMP_MIB_ITEM("RcvWndConflictUpdate", MPTCP_MIB_RCVWNDCONFLICTUPDATE),
SNMP_MIB_ITEM("RcvWndConflict", MPTCP_MIB_RCVWNDCONFLICT),
+ SNMP_MIB_ITEM("MPCurrEstab", MPTCP_MIB_CURRESTAB),
SNMP_MIB_SENTINEL
};

diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index cae71d9472529..dd7fd1f246b5f 100644
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -65,6 +65,7 @@ enum linux_mptcp_mib_field {
* conflict with another subflow while updating msk rcv wnd
*/
MPTCP_MIB_RCVWNDCONFLICT, /* Conflict with while updating msk rcv wnd */
+ MPTCP_MIB_CURRESTAB, /* Current established MPTCP connections */
__MPTCP_MIB_MAX
};

@@ -95,4 +96,11 @@ static inline void __MPTCP_INC_STATS(struct net *net,
__SNMP_INC_STATS(net->mib.mptcp_statistics, field);
}

+static inline void MPTCP_DEC_STATS(struct net *net,
+ enum linux_mptcp_mib_field field)
+{
+ if (likely(net->mib.mptcp_statistics))
+ SNMP_DEC_STATS(net->mib.mptcp_statistics, field);
+}
+
bool mptcp_mib_alloc(struct net *net);
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 9d4d5dbdbb53b..7765514451ded 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2877,6 +2877,24 @@ void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how)
release_sock(ssk);
}

+void mptcp_set_state(struct sock *sk, int state)
+{
+ int oldstate = sk->sk_state;
+
+ switch (state) {
+ case TCP_ESTABLISHED:
+ if (oldstate != TCP_ESTABLISHED)
+ MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_CURRESTAB);
+ break;
+
+ default:
+ if (oldstate == TCP_ESTABLISHED)
+ MPTCP_DEC_STATS(sock_net(sk), MPTCP_MIB_CURRESTAB);
+ }
+
+ inet_sk_state_store(sk, state);
+}
+
static const unsigned char new_state[16] = {
/* current state: new state: action: */
[0 /* (Invalid) */] = TCP_CLOSE,
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 094d3fd47a92f..01778ffa86be1 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -642,6 +642,7 @@ bool __mptcp_close(struct sock *sk, long timeout);
void mptcp_cancel_work(struct sock *sk);
void __mptcp_unaccepted_force_close(struct sock *sk);
void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk);
+void mptcp_set_state(struct sock *sk, int state);

bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
const struct mptcp_addr_info *b, bool use_port);
--
2.43.0