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>

diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c
index 3780c29..b0429ac 100644 (file)
--- a/net/mptcp/mib.c
+++ b/net/mptcp/mib.c
@@ -13,6 +13,7 @@ static const struct snmp_mib mptcp_snmp_list[] = {
        SNMP_MIB_ITEM("MPCapableACKRX", MPTCP_MIB_MPCAPABLEPASSIVEACK),
        SNMP_MIB_ITEM("MPCapableFallbackACK", MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK),
        SNMP_MIB_ITEM("MPCapableFallbackSYNACK", MPTCP_MIB_MPCAPABLEACTIVEFALLBACK),
+       SNMP_MIB_ITEM("MPFallbackTokenInit", MPTCP_MIB_TOKENFALLBACKINIT),
        SNMP_MIB_ITEM("MPTCPRetrans", MPTCP_MIB_RETRANSSEGS),
        SNMP_MIB_ITEM("MPJoinNoTokenFound", MPTCP_MIB_JOINNOTOKEN),
        SNMP_MIB_ITEM("MPJoinSynRx", MPTCP_MIB_JOINSYNRX),

diff --git a/net/mptcp/mib.h b/net/mptcp/mib.h
index 72afbc1..50e1668 100644 (file)
--- a/net/mptcp/mib.h
+++ b/net/mptcp/mib.h
@@ -6,6 +6,7 @@ enum linux_mptcp_mib_field {
        MPTCP_MIB_MPCAPABLEPASSIVEACK,  /* Received third ACK with MP_CAPABLE */
        MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK,/* Server-side fallback during 3-way handshake */
        MPTCP_MIB_MPCAPABLEACTIVEFALLBACK, /* Client-side fallback during 3-way handshake */
+       MPTCP_MIB_TOKENFALLBACKINIT,    /* Could not init/allocate token */
        MPTCP_MIB_RETRANSSEGS,          /* Segments retransmitted at the MPTCP-level */
        MPTCP_MIB_JOINNOTOKEN,          /* Received MP_JOIN but the token was not found */
        MPTCP_MIB_JOINSYNRX,            /* Received a SYN + MP_JOIN */

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 171b775..3b50e8c 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3224,8 +3224,10 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
        if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
                mptcp_subflow_early_fallback(msk, subflow);
 #endif
-       if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk))
+       if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) {
+               MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT);
                mptcp_subflow_early_fallback(msk, subflow);
+       }
 
 do_connect:
        err = ssock->ops->connect(ssock, uaddr, addr_len, flags);

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 6c074d3..b96e8dc 100644 (file)
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -165,6 +165,7 @@ again:
                        if (mptcp_token_exists(subflow_req->token)) {
                                if (retries-- > 0)
                                        goto again;
+                               SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT);
                        } else {
                                subflow_req->mp_capable = 1;
                        }
@@ -176,6 +177,8 @@ again:
                        subflow_req->mp_capable = 1;
                else if (retries-- > 0)
                        goto again;
+               else
+                       SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_TOKENFALLBACKINIT);
 
        } else if (mp_opt.mp_join && listener->request_mptcp) {
                subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq;