atm: Allow MSG_PEEK for atm sockets
Now that the vcc backends do the right thing with respect the receive
queue on registration, allow MSK_PEEK for atm sockets.
This allows a userspace program to inspect the packets and decide what
backend to use to handle them.
Signed-off-by: Jorge Boncompte [DTI2] <jorge@dti2.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/atm/common.c b/net/atm/common.c
index 0b4c58fe..b4b44db 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -522,8 +522,11 @@
if (sock->state != SS_CONNECTED)
return -ENOTCONN;
- if (flags & ~MSG_DONTWAIT) /* only handle MSG_DONTWAIT */
+
+ /* only handle MSG_DONTWAIT and MSG_PEEK */
+ if (flags & ~(MSG_DONTWAIT | MSG_PEEK))
return -EOPNOTSUPP;
+
vcc = ATM_SD(sock);
if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
test_bit(ATM_VF_CLOSE, &vcc->flags) ||
@@ -544,8 +547,13 @@
if (error)
return error;
sock_recv_ts_and_drops(msg, sk, skb);
- pr_debug("%d -= %d\n", atomic_read(&sk->sk_rmem_alloc), skb->truesize);
- atm_return(vcc, skb->truesize);
+
+ if (!(flags & MSG_PEEK)) {
+ pr_debug("%d -= %d\n", atomic_read(&sk->sk_rmem_alloc),
+ skb->truesize);
+ atm_return(vcc, skb->truesize);
+ }
+
skb_free_datagram(sk, skb);
return copied;
}