net: Add Software fallback infrastructure for socket dependent offloads

With socket dependent offloads we rely on the netdev to transform
the transmitted packets before sending them to the wire.
When a packet from an offloaded socket is rerouted to a different
device we need to detect it and do the transformation in software.

Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sock.h b/include/net/sock.h
index 74d725f..3c568b3 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -481,6 +481,11 @@ struct sock {
        void                    (*sk_error_report)(struct sock *sk);
        int                     (*sk_backlog_rcv)(struct sock *sk,
                                                  struct sk_buff *skb);
+#ifdef CONFIG_SOCK_VALIDATE_XMIT
+       struct sk_buff*         (*sk_validate_xmit_skb)(struct sock *sk,
+                                                       struct net_device *dev,
+                                                       struct sk_buff *skb);
+#endif
        void                    (*sk_destruct)(struct sock *sk);
        struct sock_reuseport __rcu     *sk_reuseport_cb;
        struct rcu_head         sk_rcu;
@@ -2332,6 +2337,22 @@ static inline bool sk_fullsock(const struct sock *sk)
        return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
 }
 
+/* Checks if this SKB belongs to an HW offloaded socket
+ * and whether any SW fallbacks are required based on dev.
+ */
+static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
+                                                  struct net_device *dev)
+{
+#ifdef CONFIG_SOCK_VALIDATE_XMIT
+       struct sock *sk = skb->sk;
+
+       if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb)
+               skb = sk->sk_validate_xmit_skb(sk, dev, skb);
+#endif
+
+       return skb;
+}
+
 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
  */

diff --git a/net/Kconfig b/net/Kconfig
index 6fa1a44..b62089f 100644 (file)
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -407,6 +407,9 @@ config GRO_CELLS
        bool
        default n
 
+config SOCK_VALIDATE_XMIT
+       bool
+
 config NET_DEVLINK
        tristate "Network physical/parent device Netlink interface"
        help

diff --git a/net/core/dev.c b/net/core/dev.c
index e01c21a..8944e1e 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3112,6 +3112,10 @@ static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device
        if (unlikely(!skb))
                goto out_null;
 
+       skb = sk_validate_xmit_skb(skb, dev);
+       if (unlikely(!skb))
+               goto out_null;
+
        if (netif_needs_gso(skb, features)) {
                struct sk_buff *segs;