[TCP]: SNMPv2 tcpAttemptFails counter error

Refer to RFC2012, tcpAttemptFails is defined as following:
  tcpAttemptFails OBJECT-TYPE
      SYNTAX      Counter32
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
              "The number of times TCP connections have made a direct
              transition to the CLOSED state from either the SYN-SENT
              state or the SYN-RCVD state, plus the number of times TCP
              connections have made a direct transition to the LISTEN
              state from the SYN-RCVD state."
      ::= { tcp 7 }

When I lookup into RFC793, I found that the state change should occured
under following condition:
  1. SYN-SENT -> CLOSED
     a) Received ACK,RST segment when SYN-SENT state.

  2. SYN-RCVD -> CLOSED
     b) Received SYN segment when SYN-RCVD state(came from LISTEN).
     c) Received RST segment when SYN-RCVD state(came from SYN-SENT).
     d) Received SYN segment when SYN-RCVD state(came from SYN-SENT).

  3. SYN-RCVD -> LISTEN
     e) Received RST segment when SYN-RCVD state(came from LISTEN).

In my test, those direct state transition can not be counted to
tcpAttemptFails.

Signed-off-by: Wei Yongjun <yjwei@nanjing-fnst.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 2 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f6f39e814291..4b04c3edd4a9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -438,7 +438,6 @@ void tcp_v4_err(struct sk_buff *skb, u32 info)
                                It can f.e. if SYNs crossed.
                              */
                 if (!sock_owned_by_user(sk)) {
-                        TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
                         sk->sk_err = err;
 
                         sk->sk_error_report(sk);
@@ -874,7 +873,6 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 drop_and_free:
         reqsk_free(req);
 drop:
-        TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
         return 0;
 }