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| author | Wei Yongjun <yjwei@nanjing-fnst.com> | 2006-07-30 20:35:54 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2006-08-02 13:38:19 -0700 |
| commit | 3687b1dc6fe83a500ba4d3235704594f6a111a2d (patch) | |
| tree | d57932b49d53234ea5daf2f2cbe780a8c347a1ad /net/ipv4/tcp_minisocks.c | |
| parent | 118075b3cdc90e0815362365f3fc64d672ace0d6 (diff) | |
| download | lwn-3687b1dc6fe83a500ba4d3235704594f6a111a2d.tar.gz lwn-3687b1dc6fe83a500ba4d3235704594f6a111a2d.zip | |
[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>
Diffstat (limited to 'net/ipv4/tcp_minisocks.c')
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 0ccb7cb22b15..624e2b2c7f53 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -589,8 +589,10 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb, /* 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. |