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authorMario Schuknecht <m.schuknecht@dresearch.de>2011-03-09 14:08:09 -0800
committerDavid S. Miller <davem@davemloft.net>2011-03-09 14:08:09 -0800
commit2f4e1b3970973bbb57cc3a3b9d67e67c1c648c37 (patch)
treed7b4d7d64ed8a02c3cd10064eb9d8e177d2be5c3
parentee3f1aaf930b7cfbf3d34eff1e5e076393227e90 (diff)
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>
-rw-r--r--include/linux/sockios.h4
-rw-r--r--net/ipv4/tcp.c9
2 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/sockios.h b/include/linux/sockios.h
index 241f179347d..7997a506ad4 100644
--- a/include/linux/sockios.h
+++ b/include/linux/sockios.h
@@ -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 */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index a17a5a72b98..b22d4501054 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;
}