[DCCP]: Implement SIOCINQ/FIONREAD

Just like UDP.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Leandro Melo de Sales <leandroal@gmail.com>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 31 insertions, 2 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index cc9bf1cb2646..d84973928033 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -26,6 +26,7 @@
 #include <net/sock.h>
 #include <net/xfrm.h>
 
+#include <asm/ioctls.h>
 #include <asm/semaphore.h>
 #include <linux/spinlock.h>
 #include <linux/timer.h>
@@ -378,8 +379,36 @@ EXPORT_SYMBOL_GPL(dccp_poll);
 
 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 {
-        dccp_pr_debug("entry\n");
-        return -ENOIOCTLCMD;
+        int rc = -ENOTCONN;
+
+        lock_sock(sk);
+
+        if (sk->sk_state == DCCP_LISTEN)
+                goto out;
+
+        switch (cmd) {
+        case SIOCINQ: {
+                struct sk_buff *skb;
+                unsigned long amount = 0;
+
+                skb = skb_peek(&sk->sk_receive_queue);
+                if (skb != NULL) {
+                        /*
+                         * We will only return the amount of this packet since
+                         * that is all that will be read.
+                         */
+                        amount = skb->len;
+                }
+                rc = put_user(amount, (int __user *)arg);
+        }
+                break;
+        default:
+                rc = -ENOIOCTLCMD;
+                break;
+        }
+out:
+        release_sock(sk);
+        return rc;
 }
 
 EXPORT_SYMBOL_GPL(dccp_ioctl);