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>

diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index 3240b72..7558802 100644 (file)
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -35,12 +35,14 @@ static const struct snmp_mib mptcp_snmp_list[] = {
        SNMP_MIB_ITEM("AddAddr", MPTCP_MIB_ADDADDR),
        SNMP_MIB_ITEM("EchoAdd", MPTCP_MIB_ECHOADD),
        SNMP_MIB_ITEM("PortAdd", MPTCP_MIB_PORTADD),
+       SNMP_MIB_ITEM("AddAddrDrop", MPTCP_MIB_ADDADDRDROP),
        SNMP_MIB_ITEM("MPJoinPortSynRx", MPTCP_MIB_JOINPORTSYNRX),
        SNMP_MIB_ITEM("MPJoinPortSynAckRx", MPTCP_MIB_JOINPORTSYNACKRX),
        SNMP_MIB_ITEM("MPJoinPortAckRx", MPTCP_MIB_JOINPORTACKRX),
        SNMP_MIB_ITEM("MismatchPortSynRx", MPTCP_MIB_MISMATCHPORTSYNRX),
        SNMP_MIB_ITEM("MismatchPortAckRx", MPTCP_MIB_MISMATCHPORTACKRX),
        SNMP_MIB_ITEM("RmAddr", MPTCP_MIB_RMADDR),
+       SNMP_MIB_ITEM("RmAddrDrop", MPTCP_MIB_RMADDRDROP),
        SNMP_MIB_ITEM("RmSubflow", MPTCP_MIB_RMSUBFLOW),
        SNMP_MIB_ITEM("MPPrioTx", MPTCP_MIB_MPPRIOTX),
        SNMP_MIB_ITEM("MPPrioRx", MPTCP_MIB_MPPRIORX),

diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index ecd3d8b..2966fcb 100644 (file)
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -28,12 +28,14 @@ enum linux_mptcp_mib_field {
        MPTCP_MIB_ADDADDR,              /* Received ADD_ADDR with echo-flag=0 */
        MPTCP_MIB_ECHOADD,              /* Received ADD_ADDR with echo-flag=1 */
        MPTCP_MIB_PORTADD,              /* Received ADD_ADDR with a port-number */
+       MPTCP_MIB_ADDADDRDROP,          /* Dropped incoming ADD_ADDR */
        MPTCP_MIB_JOINPORTSYNRX,        /* Received a SYN MP_JOIN with a different port-number */
        MPTCP_MIB_JOINPORTSYNACKRX,     /* Received a SYNACK MP_JOIN with a different port-number */
        MPTCP_MIB_JOINPORTACKRX,        /* Received an ACK MP_JOIN with a different port-number */
        MPTCP_MIB_MISMATCHPORTSYNRX,    /* Received a SYN MP_JOIN with a mismatched port-number */
        MPTCP_MIB_MISMATCHPORTACKRX,    /* Received an ACK MP_JOIN with a mismatched port-number */
        MPTCP_MIB_RMADDR,               /* Received RM_ADDR */
+       MPTCP_MIB_RMADDRDROP,           /* Dropped incoming RM_ADDR */
        MPTCP_MIB_RMSUBFLOW,            /* Remove a subflow */
        MPTCP_MIB_MPPRIOTX,             /* Transmit a MP_PRIO */
        MPTCP_MIB_MPPRIORX,             /* Received a MP_PRIO */

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 696b2c4..7bea318 100644 (file)
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -213,6 +213,8 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
                mptcp_pm_add_addr_send_ack(msk);
        } else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
                pm->remote = *addr;
+       } else {
+               __MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
        }
 
        spin_unlock_bh(&pm->lock);
@@ -253,8 +255,10 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
                mptcp_event_addr_removed(msk, rm_list->ids[i]);
 
        spin_lock_bh(&pm->lock);
-       mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED);
-       pm->rm_list_rx = *rm_list;
+       if (mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED))
+               pm->rm_list_rx = *rm_list;
+       else
+               __MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_RMADDRDROP);
        spin_unlock_bh(&pm->lock);
 }