[v16,11/17] Add a hook to intercept external buffers from NIC driver.

Commit Message

Xin, Xiaohui Dec. 1, 2010, 8:08 a.m. UTC

None

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 84fbb83..bdad1c8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2814,6 +2814,40 @@  int __skb_bond_should_drop(struct sk_buff *skb, struct net_device *master)
 }
 EXPORT_SYMBOL(__skb_bond_should_drop);
 
+#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE)
+/* Add a hook to intercept mediate passthru(zero-copy) packets,
+ * and insert it to the socket queue owned by mp_port specially.
+ */
+static inline struct sk_buff *handle_mpassthru(struct sk_buff *skb,
+					       struct packet_type **pt_prev,
+					       int *ret,
+					       struct net_device *orig_dev)
+{
+	struct mp_port *mp_port = NULL;
+	struct sock *sk = NULL;
+
+	if (!dev_is_mpassthru(skb->dev) && !dev_is_mpassthru(orig_dev))
+		return skb;
+	if (dev_is_mpassthru(skb->dev))
+		mp_port = skb->dev->mp_port;
+	else if (orig_dev->master == skb->dev && dev_is_mpassthru(orig_dev))
+		mp_port = orig_dev->mp_port;
+
+	if (*pt_prev) {
+		*ret = deliver_skb(skb, *pt_prev, orig_dev);
+		*pt_prev = NULL;
+	}
+
+	sk = mp_port->sock->sk;
+	skb_queue_tail(&sk->sk_receive_queue, skb);
+	sk->sk_state_change(sk);
+
+	return NULL;
+}
+#else
+#define handle_mpassthru(skb, pt_prev, ret, orig_dev)     (skb)
+#endif
+
 static int __netif_receive_skb(struct sk_buff *skb)
 {
 	struct packet_type *ptype, *pt_prev;
@@ -2891,6 +2925,11 @@  static int __netif_receive_skb(struct sk_buff *skb)
 ncls:
 #endif
 
+	/* To intercept mediate passthru(zero-copy) packets here */
+	skb = handle_mpassthru(skb, &pt_prev, &ret, orig_dev);
+	if (!skb)
+		goto out;
+
 	/* Handle special case of bridge or macvlan */
 	rx_handler = rcu_dereference(skb->dev->rx_handler);
 	if (rx_handler) {
@@ -2983,6 +3022,7 @@  err:
 EXPORT_SYMBOL(netdev_mp_port_prep);
 #endif
 
+
 /**
  *	netif_receive_skb - process receive buffer from network
  *	@skb: buffer to process