From 3687b1dc6fe83a500ba4d3235704594f6a111a2d Mon Sep 17 00:00:00 2001
From: Wei Yongjun <yjwei@nanjing-fnst.com>
Date: Sun, 30 Jul 2006 20:35:54 -0700
Subject: [PATCH] [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>
---
include/net/tcp.h | 3 +++
net/ipv4/tcp_ipv4.c | 2 --
net/ipv4/tcp_minisocks.c | 4 +++-
net/ipv6/tcp_ipv6.c | 2 --
4 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 0720bddff1e9..7a093d0aa0fe 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -914,6 +914,9 @@ static inline void tcp_set_state(struct sock *sk, int state)
static inline void tcp_done(struct sock *sk)
{
+ if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
+ TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
+
tcp_set_state(sk, TCP_CLOSE);
tcp_clear_xmit_timers(sk);
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;
}
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.
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index b76fd7fba5f5..b843a650be71 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -427,7 +427,6 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
case TCP_SYN_RECV: /* Cannot happen.
It can, it SYNs are crossed. --ANK */
if (!sock_owned_by_user(sk)) {
- TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
sk->sk_err = err;
sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
@@ -831,7 +830,6 @@ drop:
if (req)
reqsk_free(req);
- TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
return 0; /* don't send reset */
}
--
2.20.1