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

[Steffen Sledz <sledz@dresearch.de>]

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

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