2 files changed, 12 insertions, 1 deletions

diff --git a/include/linux/sockios.h b/include/linux/sockios.h
index 241f179347d9..7997a506ad41 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 a17a5a72b98d..b22d45010545 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;
         }