[PATCH] tcp: ioctl type SIOCOUTQNSD returns amount of data not sent

[PATCH] tcp: ioctl type SIOCOUTQNSD returns amount of data not sent

[Mario Schuknecht]

In contrast to SIOCOUTQ which returns the amount of data sent
but not yet acknowledged plus data not yet sent this patch only
returns the data not sent.

For various methods of live streaming bitrate control it may
be helpful to know how much data are in the tcp outqueue are
not sent yet.

Signed-off-by: Mario Schuknecht <m.schuknecht@dresearch.de>
---
 include/asm-generic/ioctls.h |    1 +
 include/linux/sockios.h      |    1 +
 net/ipv4/tcp.c               |    9 +++++++++
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/include/asm-generic/ioctls.h b/include/asm-generic/ioctls.h
index a321665..b87115b 100644
--- a/include/asm-generic/ioctls.h
+++ b/include/asm-generic/ioctls.h
@@ -72,6 +72,7 @@
 #define TCSETXF		0x5434
 #define TCSETXW		0x5435
 #define TIOCSIG		_IOW('T', 0x36, int)  /* pty: generate signal */
+#define TIOCOUTQNSD	0x5437
 
 #define FIONCLEX	0x5450
 #define FIOCLEX		0x5451
diff --git a/include/linux/sockios.h b/include/linux/sockios.h
index 241f179..4c5ca47 100644
--- a/include/linux/sockios.h
+++ b/include/linux/sockios.h
@@ -23,6 +23,7 @@
 /* Linux-specific socket ioctls */
 #define SIOCINQ		FIONREAD
 #define SIOCOUTQ	TIOCOUTQ
+#define SIOCOUTQNSD	TIOCOUTQNSD
 
 /* Routing table calls. */
 #define SIOCADDRT	0x890B		/* add routing table entry	*/
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1664a05..c2d52e8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -505,6 +505,15 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 		else
 			answ = tp->write_seq - tp->snd_una;
 		break;
+	case SIOCOUTQNSD:
+		if (sk->sk_state == TCP_LISTEN)
+			return -EINVAL;
+
+		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
+			answ = 0;
+		else
+			answ = tp->write_seq - tp->snd_nxt;
+		break;
 	default:
 		return -ENOIOCTLCMD;
 	}
-- 
1.7.1

Re: [PATCH] tcp: ioctl type SIOCOUTQNSD returns amount of data not sent

[Steffen Sledz]

Am 05.10.2010 11:32, schrieb Mario Schuknecht:
> In contrast to SIOCOUTQ which returns the amount of data sent
> but not yet acknowledged plus data not yet sent this patch only
> returns the data not sent.
> 
> For various methods of live streaming bitrate control it may
> be helpful to know how much data are in the tcp outqueue are
> not sent yet.
> 
> Signed-off-by: Mario Schuknecht <m.schuknecht@dresearch.de>
> ---
>  include/asm-generic/ioctls.h |    1 +
>  include/linux/sockios.h      |    1 +
>  net/ipv4/tcp.c               |    9 +++++++++
>  3 files changed, 11 insertions(+), 0 deletions(-)
> 
> diff --git a/include/asm-generic/ioctls.h b/include/asm-generic/ioctls.h
> index a321665..b87115b 100644
> --- a/include/asm-generic/ioctls.h
> +++ b/include/asm-generic/ioctls.h
> @@ -72,6 +72,7 @@
>  #define TCSETXF		0x5434
>  #define TCSETXW		0x5435
>  #define TIOCSIG		_IOW('T', 0x36, int)  /* pty: generate signal */
> +#define TIOCOUTQNSD	0x5437
>  
>  #define FIONCLEX	0x5450
>  #define FIOCLEX		0x5451
> diff --git a/include/linux/sockios.h b/include/linux/sockios.h
> index 241f179..4c5ca47 100644
> --- a/include/linux/sockios.h
> +++ b/include/linux/sockios.h
> @@ -23,6 +23,7 @@
>  /* Linux-specific socket ioctls */
>  #define SIOCINQ		FIONREAD
>  #define SIOCOUTQ	TIOCOUTQ
> +#define SIOCOUTQNSD	TIOCOUTQNSD
>  
>  /* Routing table calls. */
>  #define SIOCADDRT	0x890B		/* add routing table entry	*/
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 1664a05..c2d52e8 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -505,6 +505,15 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
>  		else
>  			answ = tp->write_seq - tp->snd_una;
>  		break;
> +	case SIOCOUTQNSD:
> +		if (sk->sk_state == TCP_LISTEN)
> +			return -EINVAL;
> +
> +		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
> +			answ = 0;
> +		else
> +			answ = tp->write_seq - tp->snd_nxt;
> +		break;
>  	default:
>  		return -ENOIOCTLCMD;
>  	}

Ping!

It would be nice to get some feedback on this. We really need an extension of this kind.

If the patch does something in a wrong way (esp. choosing the TIOCOUTQNSD id) please give us a hint how to do it in the right way.

Thx,
Steffen Sledz

-- 
DResearch Fahrzeugelektronik GmbH
Otto-Schmirgal-Str. 3, 10319 Berlin, Germany
Tel: +49 30 515932-237 mailto:sledz@DResearch.de
Fax: +49 30 515932-299
Geschäftsführer: Dr. Michael Weber, Werner Mögle;
Amtsgericht Berlin Charlottenburg; HRB 130120 B;
Ust.-IDNr. DE273952058

Re: [PATCH] tcp: ioctl type SIOCOUTQNSD returns amount of data not sent

[Alan Cox]

On Wed, 23 Feb 2011 13:14:10 +0100
Steffen Sledz <sledz@dresearch.de> wrote:

> Am 05.10.2010 11:32, schrieb Mario Schuknecht:
> > In contrast to SIOCOUTQ which returns the amount of data sent
> > but not yet acknowledged plus data not yet sent this patch only
> > returns the data not sent.
> > 
> > For various methods of live streaming bitrate control it may
> > be helpful to know how much data are in the tcp outqueue are
> > not sent yet.
> > 
> > Signed-off-by: Mario Schuknecht <m.schuknecht@dresearch.de>
> > ---
> >  include/asm-generic/ioctls.h |    1 +
> >  include/linux/sockios.h      |    1 +
> >  net/ipv4/tcp.c               |    9 +++++++++
> >  3 files changed, 11 insertions(+), 0 deletions(-)
> > 
> > diff --git a/include/asm-generic/ioctls.h b/include/asm-generic/ioctls.h
> > index a321665..b87115b 100644
> > --- a/include/asm-generic/ioctls.h
> > +++ b/include/asm-generic/ioctls.h
> > @@ -72,6 +72,7 @@
> >  #define TCSETXF		0x5434
> >  #define TCSETXW		0x5435
> >  #define TIOCSIG		_IOW('T', 0x36, int)  /* pty: generate signal */
> > +#define TIOCOUTQNSD	0x5437

These are tty not socket ioctl codes. For various historical reasons some
of them got sort of emulated by the socket layer in Unix and thus in
Linux.

If you plan to add one to Linux then please post the accompanying *tty
layer* patches and reasoning, otherwise if it is socket only please stick
to the socket ioctl.

Alan