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. Following is my patch:
Signed-off-by: Wei Yongjun <[EMAIL PROTECTED]>
--- a/net/ipv4/tcp_input.c 2006-06-30 13:37:38.000000000 -0400
+++ b/net/ipv4/tcp_input.c 2006-07-05 04:45:04.000000000 -0400
@@ -4089,6 +4089,7 @@ static int tcp_rcv_synsent_state_process
*/
if (th->rst) {
+ TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
tcp_reset(sk);
goto discard;
}
@@ -4377,6 +4378,8 @@ int tcp_rcv_state_process(struct sock *s
/* step 2: check RST bit */
if(th->rst) {
+ if(sk->sk_state == TCP_SYN_RECV)
+ TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
tcp_reset(sk);
goto discard;
}
@@ -4390,6 +4393,8 @@ int tcp_rcv_state_process(struct sock *s
* Check for a SYN in window.
*/
if (th->syn && !before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
+ if(sk->sk_state == TCP_SYN_RECV)
+ TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
NET_INC_STATS_BH(LINUX_MIB_TCPABORTONSYN);
tcp_reset(sk);
return 1;
--- a/net/ipv4/tcp_minisocks.c 2006-06-30 13:37:38.000000000 -0400
+++ b/net/ipv4/tcp_minisocks.c 2006-07-05 04:45:04.000000000 -0400
@@ -592,8 +592,10 @@ struct sock *tcp_check_req(struct sock *
/* RFC793: "second check the RST bit" and
* "fourth, check the SYN bit"
*/
- if (flg & (TCP_FLAG_RST|TCP_FLAG_SYN))
+ if (flg & (TCP_FLAG_RST|TCP_FLAG_SYN)) {
+ TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
goto embryonic_reset;
+ }
/* ACK sequence verified above, just make sure ACK is
* set. If ACK not set, just silently drop the packet.
-
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