RE: [External] : [PATCH 1/2] tcp: fix get_tcp4_sock() output error info

[Mohith Kumar Thummaluru <mohith.k.kumar.thummaluru@oracle.com>]

Good catch! Thanks for this fix. 

LGTM.

Reviewed-by : Mohith Kumar Thummaluru <mohith.k.kumar.thummaluru@oracle.com>
Tested-by: Mohith Kumar Thummaluru <mohith.k.kumar.thummaluru@oracle.com>

Regards,
Mohith

-----Original Message-----
From: Yuan Fang <yf768672249@gmail.com> 
Sent: 09 May 2024 10:13
To: edumazet@google.com
Cc: davem@davemloft.net; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Yuan Fang <yf768672249@gmail.com>
Subject: [External] : [PATCH 1/2] tcp: fix get_tcp4_sock() output error info

When in the TCP_LISTEN state, using netstat,the Send-Q is always 0.
Modify tx_queue to the value of sk->sk_max_ack_backlog.

Signed-off-by: Yuan Fang <yf768672249@gmail.com>
---
 net/ipv4/tcp_ipv4.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index a22ee5838751..70416ba902b9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2867,7 +2867,7 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
 	__be32 src = inet->inet_rcv_saddr;
 	__u16 destp = ntohs(inet->inet_dport);
 	__u16 srcp = ntohs(inet->inet_sport);
-	int rx_queue;
+	int rx_queue, tx_queue;
 	int state;
 
 	if (icsk->icsk_pending == ICSK_TIME_RETRANS || @@ -2887,19 +2887,22 @@ static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i)
 	}
 
 	state = inet_sk_state_load(sk);
-	if (state == TCP_LISTEN)
+	if (state == TCP_LISTEN) {
 		rx_queue = READ_ONCE(sk->sk_ack_backlog);
-	else
+		tx_queue = READ_ONCE(sk->sk_max_ack_backlog);
+	} else {
 		/* Because we don't lock the socket,
 		 * we might find a transient negative value.
 		 */
 		rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
 				      READ_ONCE(tp->copied_seq), 0);
+		tx_queue = READ_ONCE(tp->write_seq) - tp->snd_una;
+	}
 
 	seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
 			"%08X %5u %8d %lu %d %pK %lu %lu %u %u %d",
 		i, src, srcp, dest, destp, state,
-		READ_ONCE(tp->write_seq) - tp->snd_una,
+		tx_queue,
 		rx_queue,
 		timer_active,
 		jiffies_delta_to_clock_t(timer_expires - jiffies),
--
2.45.0