+static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
+{
+ struct sock *sk = &po->sk;
+ bool has_room;
+
+ if (po->prot_hook.func != tpacket_rcv)
+ return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
+ <= sk->sk_rcvbuf;
+
+ spin_lock(&sk->sk_receive_queue.lock);
+ if (po->tp_version == TPACKET_V3)
+ has_room = prb_lookup_block(po, &po->rx_ring,
+ po->rx_ring.prb_bdqc.kactive_blk_num,
+ TP_STATUS_KERNEL);
+ else
+ has_room = packet_lookup_frame(po, &po->rx_ring,
+ po->rx_ring.head,
+ TP_STATUS_KERNEL);
+ spin_unlock(&sk->sk_receive_queue.lock);
+
+ return has_room;
+}
+