tcp: ioctl type SIOCOUTQNSD returns amount of data not sent

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>
Signed-off-by: Steffen Sledz <sledz@dresearch.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mario Schuknecht 2011-03-09 14:08:09 -08:00 committed by David S. Miller
parent ee3f1aaf93
commit 2f4e1b3970
2 changed files with 12 additions and 1 deletions

View file

@ -22,7 +22,7 @@
/* Linux-specific socket ioctls */
#define SIOCINQ FIONREAD
#define SIOCOUTQ TIOCOUTQ
#define SIOCOUTQ TIOCOUTQ /* output queue size (not sent + not acked) */
/* Routing table calls. */
#define SIOCADDRT 0x890B /* add routing table entry */
@ -83,6 +83,8 @@
#define SIOCWANDEV 0x894A /* get/set netdev parameters */
#define SIOCOUTQNSD 0x894B /* output queue size (not sent only) */
/* ARP cache control calls. */
/* 0x8950 - 0x8952 * obsolete calls, don't re-use */
#define SIOCDARP 0x8953 /* delete ARP table entry */

View file

@ -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;
}