net/tcp_fastopen: Add snmp counter for blackhole detection
This counter records the number of times the firewall blackhole issue is
detected and active TFO is disabled.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index c1abc2a..da28bef 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1507,7 +1507,7 @@ struct tcp_fastopen_context {
};
extern unsigned int sysctl_tcp_fastopen_blackhole_timeout;
-void tcp_fastopen_active_disable(void);
+void tcp_fastopen_active_disable(struct sock *sk);
bool tcp_fastopen_active_should_disable(struct sock *sk);
void tcp_fastopen_active_disable_ofo_check(struct sock *sk);
void tcp_fastopen_active_timeout_reset(void);
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index cec0e17..95cffcb 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -259,6 +259,7 @@ enum
LINUX_MIB_TCPFASTOPENPASSIVEFAIL, /* TCPFastOpenPassiveFail */
LINUX_MIB_TCPFASTOPENLISTENOVERFLOW, /* TCPFastOpenListenOverflow */
LINUX_MIB_TCPFASTOPENCOOKIEREQD, /* TCPFastOpenCookieReqd */
+ LINUX_MIB_TCPFASTOPENBLACKHOLE, /* TCPFastOpenBlackholeDetect */
LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES, /* TCPSpuriousRtxHostQueues */
LINUX_MIB_BUSYPOLLRXPACKETS, /* BusyPollRxPackets */
LINUX_MIB_TCPAUTOCORKING, /* TCPAutoCorking */
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 4ccbf46..fa44e75 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -281,6 +281,7 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPFastOpenPassiveFail", LINUX_MIB_TCPFASTOPENPASSIVEFAIL),
SNMP_MIB_ITEM("TCPFastOpenListenOverflow", LINUX_MIB_TCPFASTOPENLISTENOVERFLOW),
SNMP_MIB_ITEM("TCPFastOpenCookieReqd", LINUX_MIB_TCPFASTOPENCOOKIEREQD),
+ SNMP_MIB_ITEM("TCPFastOpenBlackhole", LINUX_MIB_TCPFASTOPENBLACKHOLE),
SNMP_MIB_ITEM("TCPSpuriousRtxHostQueues", LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES),
SNMP_MIB_ITEM("BusyPollRxPackets", LINUX_MIB_BUSYPOLLRXPACKETS),
SNMP_MIB_ITEM("TCPAutoCorking", LINUX_MIB_TCPAUTOCORKING),
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index ff2d30f..4af82b9 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -410,10 +410,11 @@ static unsigned long tfo_active_disable_stamp __read_mostly;
/* Disable active TFO and record current jiffies and
* tfo_active_disable_times
*/
-void tcp_fastopen_active_disable(void)
+void tcp_fastopen_active_disable(struct sock *sk)
{
atomic_inc(&tfo_active_disable_times);
tfo_active_disable_stamp = jiffies;
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENBLACKHOLE);
}
/* Reset tfo_active_disable_times to 0 */
@@ -469,7 +470,7 @@ void tcp_fastopen_active_disable_ofo_check(struct sock *sk)
if (p && !rb_next(p)) {
skb = rb_entry(p, struct sk_buff, rbnode);
if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
- tcp_fastopen_active_disable();
+ tcp_fastopen_active_disable(sk);
return;
}
}
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 9f342a6..5af2f04 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5307,7 +5307,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
*/
if (tp->syn_fastopen && !tp->data_segs_in &&
sk->sk_state == TCP_ESTABLISHED)
- tcp_fastopen_active_disable();
+ tcp_fastopen_active_disable(sk);
tcp_send_challenge_ack(sk, skb);
}
goto discard;
@@ -6061,7 +6061,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) {
/* Receive out of order FIN after close() */
if (tp->syn_fastopen && th->fin)
- tcp_fastopen_active_disable();
+ tcp_fastopen_active_disable(sk);
tcp_done(sk);
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
return 1;