include listenq max backlog in /proc/net/tcp and include in tcp_info

Return some useful information such as the maximum listen backlog and the current listen backlog in the tcp_info structure and have that match what one can see in /proc/net/tcp and /proc/net/tcp6.

Signed-off-by Rick Jones <[email protected]>

---

diff -r bdcdd0e1ee9d Documentation/networking/proc_net_tcp.txt

Documentation/networking/proc_net_tcp.txt +2 -2

@@ -20,8 +20,8 @@ up into 3 parts because of the length of
       |        |     |     |       |--> number of unrecovered RTO timeouts
       |        |     |     |----------> number of jiffies until timer expires
       |        |     |----------------> timer_active (see below)
-      |        |----------------------> receive-queue
-      |-------------------------------> transmit-queue
+      |        |----------------------> receive-queue or connection backlog
+      |-------------------------------> transmit-queue or connection limit
 
    1000        0 54165785 4 cd1e6040 25 4 27 3 -1
     |          |    |     |    |     |  | |  | |--> slow start size threshold, 

diff -r bdcdd0e1ee9d net/ipv4/tcp.c

net/ipv4/tcp.c +8 -2

@@ -2030,8 +2030,14 @@ void tcp_get_info(struct sock *sk, struc
 	info->tcpi_snd_mss = tp->mss_cache;
 	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
 
-	info->tcpi_unacked = tp->packets_out;
-	info->tcpi_sacked = tp->sacked_out;
+	if (sk->sk_state == TCP_LISTEN) {
+		info->tcpi_unacked = sk->sk_ack_backlog;
+		info->tcpi_sacked = sk->sk_max_ack_backlog;
+	}
+	else {
+		info->tcpi_unacked = tp->packets_out;
+		info->tcpi_sacked = tp->sacked_out;
+	}
 	info->tcpi_lost = tp->lost_out;
 	info->tcpi_retrans = tp->retrans_out;
 	info->tcpi_fackets = tp->fackets_out;

diff -r bdcdd0e1ee9d net/ipv4/tcp_ipv4.c

net/ipv4/tcp_ipv4.c +2 -1

@@ -2320,7 +2320,8 @@ static void get_tcp4_sock(struct sock *s
 	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
 			"%08X %5d %8d %lu %d %p %u %u %u %u %d",
 		i, src, srcp, dest, destp, sk->sk_state,
-		tp->write_seq - tp->snd_una,
+		sk->sk_state == TCP_LISTEN ? sk->sk_max_ack_backlog :
+					     (tp->write_seq - tp->snd_una),
 		sk->sk_state == TCP_LISTEN ? sk->sk_ack_backlog :
 					     (tp->rcv_nxt - tp->copied_seq),
 		timer_active,

diff -r bdcdd0e1ee9d net/ipv6/tcp_ipv6.c

net/ipv6/tcp_ipv6.c +4 -3

@@ -2005,8 +2005,10 @@ static void get_tcp6_sock(struct seq_fil
 		   dest->s6_addr32[0], dest->s6_addr32[1],
 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
 		   sp->sk_state,
-		   tp->write_seq-tp->snd_una,
-		   (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
+		   (sp->sk_state == TCP_LISTEN) ? sp->sk_max_ack_backlog:
+						  tp->write_seq-tp->snd_una,
+		   (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : 
+					(tp->rcv_nxt - tp->copied_seq),
 		   timer_active,
 		   jiffies_to_clock_t(timer_expires - jiffies),
 		   icsk->icsk_retransmits,
-

To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

Quoted 2 lines · Rick Jones

Return some useful information such as the maximum listen backlog and
the current listen backlog in the tcp_info structure and have that match what one can see in /proc/net/tcp and /proc/net/tcp6.

If we are also exporting max listen backlog, another place to consider adding this is to tcp_diag_get_info() called via INET_DIAG_INFO. Current listen backlog is returned in inet_diag_msg->idiag_rqueue. max listen backlog can be returned in inet_diag_msg->idiag_wqueue.

Quoted 9 lines · Sridhar Samudrala

Quoted 2 lines · Rick Jones

Return some useful information such as the maximum listen backlog and
the current listen backlog in the tcp_info structure and have that match what one can see in /proc/net/tcp and /proc/net/tcp6.

If we are also exporting max listen backlog, another place to consider adding this is to tcp_diag_get_info() called via INET_DIAG_INFO. Current listen backlog is returned in inet_diag_msg->idiag_rqueue. max listen backlog can be returned in inet_diag_msg->idiag_wqueue.

I agree, /proc/net/tcp is deprecated nowadays...

Rick, could you add this part in your patch, and add my Sign-off-by ?

Thank you
Eric

Quoted 6 lines · Sridhar Samudrala

Quoted 2 lines · Rick Jones

Return some useful information such as the maximum listen backlog and
the current listen backlog in the tcp_info structure and have that match what one can see in /proc/net/tcp and /proc/net/tcp6.

Quoted 5 lines

If we are also exporting max listen backlog, another place to consider adding this is to tcp_diag_get_info() called via INET_DIAG_INFO. Current listen backlog is returned in inet_diag_msg->idiag_rqueue. max listen backlog can be returned in inet_diag_msg->idiag_wqueue.

I agree, /proc/net/tcp is deprecated nowadays...

Rick, could you add this part in your patch, and add my Sign-off-by ?

Thank you
Eric

------------------------------------------------------------------------

net/ipv4/tcp_diag.c +5 -3

index 57c5f0b..f5b6275 100644
@@ -25,11 +25,13 @@ static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 	const struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_info *info = _info;
 
-	if (sk->sk_state == TCP_LISTEN)
+	if (sk->sk_state == TCP_LISTEN) {
 		r->idiag_rqueue = sk->sk_ack_backlog;
-	else
+		r->idiag_wqueue = sk->sk_max_ack_backlog;
+	else {
 		r->idiag_rqueue = tp->rcv_nxt - tp->copied_seq;
-	r->idiag_wqueue = tp->write_seq - tp->snd_una;
+		r->idiag_wqueue = tp->write_seq - tp->snd_una;
+	}
 	if (info != NULL)
 		tcp_get_info(sk, info);
 }

Quoted 15 lines · Eric Dumazet

Quoted 12 lines · Sridhar Samudrala

Quoted 3 lines · Rick Jones

Return some useful information such as the maximum listen backlog and the current listen backlog in the tcp_info structure and have that match what one can see in /proc/net/tcp and /proc/net/tcp6.

If we are also exporting max listen backlog, another place to consider adding this is to tcp_diag_get_info() called via INET_DIAG_INFO. Current listen backlog is returned in inet_diag_msg->idiag_rqueue. max listen backlog can be returned in inet_diag_msg->idiag_wqueue.

Quoted 1 line

I agree, /proc/net/tcp is deprecated nowadays...

What takes its place?

Quoted 2 lines

Rick, could you add this part in your patch, and add my Sign-off-by ?

My pleasure.

I have a small test program for the tcp_info bit - where do I go to find how the inet diag stuff works?

BTW, what do people think about doing the same thing with the rxqueue and txqueue's of netstat output?

ss command from iproute2 package ( http://linux-net.osdl.org/index.php/Iproute2 )

Problem with /proc/net/tcp is its quadratic time O(N^2) to output N lines...

Quoted 5 lines

Quoted 1 line

Rick, could you add this part in your patch, and add my Sign-off-by ?

My pleasure.

I have a small test program for the tcp_info bit - where do I go to find how the inet diag stuff works?

ss state listen

Quoted 4 lines

BTW, what do people think about doing the same thing with the rxqueue and txqueue's of netstat output?

I dont understand this question, I thought your patch already handled this (for the txqueue, since rxqueue is already there), as netstat uses /proc/net/tcp (unfortunatly)

Quoted 3 lines

ss command from iproute2 package ( http://linux-net.osdl.org/index.php/Iproute2 )

Problem with /proc/net/tcp is its quadratic time O(N^2) to output N lines...

I could see where that might be a problem.

Quoted 8 lines

Quoted 6 lines

Quoted 1 line

Rick, could you add this part in your patch, and add my Sign-off-by ?

My pleasure.

I have a small test program for the tcp_info bit - where do I go to find how the inet diag stuff works?

Quoted 1 line

ss state listen

hpcpc103:~# ss --version
ss utility, iproute2-ss070313
hpcpc103:~# ss state listen
ss: no socket states to show with such filter.

hpcpc103:~# ss --all
State      Recv-Q Send-Q      Local Address:Port          Peer 
Address:Port
LISTEN     0      128                     *:sunrpc                   *:* 

LISTEN 0 128 *:auth *:*

LISTEN 0 128 :::ssh :::*

LISTEN 0 20 127.0.0.1:smtp *:*

LISTEN 0 128 *:42137 *:*

Quoted 10 lines

Quoted 5 lines

BTW, what do people think about doing the same thing with the rxqueue and txqueue's of netstat output?

I dont understand this question, I thought your patch already handled this (for the txqueue, since rxqueue is already there), as netstat uses /proc/net/tcp (unfortunatly)

Well, it doesn't seem to be the case. This is from the same system as the ss output above:

hpcpc103:~# netstat -an | grep LISTEN
tcp        0      0 0.0.0.0:111          0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:113          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:25         0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:42137        0.0.0.0:*               LISTEN
tcp6       0      0 :::22                :::*                    LISTEN
unix  2    [ ACC ]     STREAM   LISTENING   5666  /var/run/acpid.socket

I thought I saw some other code in there when I was stumbling around.

From tcp_do_one() in netstat.c

Quoted 16 lines

Quoted 5 lines

Quoted 2 lines

BTW, what do people think about doing the same thing with the rxqueue and txqueue's of netstat output?

I dont understand this question, I thought your patch already handled this (for the txqueue, since rxqueue is already there), as netstat uses /proc/net/tcp (unfortunatly)

Well, it doesn't seem to be the case. This is from the same system as the ss output above:

hpcpc103:~# netstat -an | grep LISTEN
tcp        0      0 0.0.0.0:111          0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:113          0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:25         0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:42137        0.0.0.0:*               LISTEN
tcp6       0      0 :::22                :::*                    LISTEN
unix  2    [ ACC ]     STREAM   LISTENING   5666  /var/run/acpid.socket

Quoted 1 line

I thought I saw some other code in there when I was stumbling around.

Yes. netstat code seems to have a explicit check for TCP_LISTEN state and zeroing txq and rxq.

Quoted 1 line

From tcp_do_one() in netstat.c

    if (state == TCP_LISTEN) {
        time_len = 0;
        retr = 0L;
        rxq = 0L;
        txq = 0L;
    }

We should fix this. Also i think it is a good idea to update netstat to use INET_DIAG_INFO instead of /proc/net/tcp.