Merge branch 'gro-in-udp'

Tom Herbert says:

====================
udp: GRO in UDP sockets

This patch set adds GRO functions (gro_receive and gro_complete) to UDP
sockets and removes udp_offload infrastructure.

Add GRO functions (gro_receive and gro_complete) to UDP sockets. In
udp_gro_receive and udp_gro_complete a socket lookup is done instead of
looking up the port number in udp_offloads.  If a socket is found and
there are GRO functions for it then those are called. This feature
allows binding GRO functions to more than just a port number.
Eventually, we will be able to use this technique to allow application
defined GRO for an application protocol by attaching BPF porgrams to UDP
sockets for doing GRO.

In order to implement these functions, we added exported
udp6_lib_lookup_skb and udp4_lib_lookup_skb functions in ipv4/udp.c and
ipv6/udp.c. Also, inet_iif and references to skb_dst() were changed to
check that dst is set in skbuf before derefencing. In the GRO path there
is now a UDP socket lookup performed before dst is set, to the get the
device in that case we simply use skb->dev.

Tested:

Ran various combinations of VXLAN and GUE TCP_STREAM and TCP_RR tests.
Did not see any material regression.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 94 deletions

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 0ed2dafb7cc4..6230cf4b0d2d 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -14,18 +14,6 @@
 #include <net/udp.h>
 #include <net/protocol.h>
 
-static DEFINE_SPINLOCK(udp_offload_lock);
-static struct udp_offload_priv __rcu *udp_offload_base __read_mostly;
-
-#define udp_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&udp_offload_lock))
-
-struct udp_offload_priv {
-	struct udp_offload	*offload;
-	possible_net_t	net;
-	struct rcu_head		rcu;
-	struct udp_offload_priv __rcu *next;
-};
-
 static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
 	netdev_features_t features,
 	struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
@@ -179,6 +167,7 @@ out_unlock:
 
 	return segs;
 }
+EXPORT_SYMBOL(skb_udp_tunnel_segment);
 
 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
 					 netdev_features_t features)
@@ -253,64 +242,14 @@ out:
 	return segs;
 }
 
-int udp_add_offload(struct net *net, struct udp_offload *uo)
-{
-	struct udp_offload_priv *new_offload = kzalloc(sizeof(*new_offload), GFP_ATOMIC);
-
-	if (!new_offload)
-		return -ENOMEM;
-
-	write_pnet(&new_offload->net, net);
-	new_offload->offload = uo;
-
-	spin_lock(&udp_offload_lock);
-	new_offload->next = udp_offload_base;
-	rcu_assign_pointer(udp_offload_base, new_offload);
-	spin_unlock(&udp_offload_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL(udp_add_offload);
-
-static void udp_offload_free_routine(struct rcu_head *head)
-{
-	struct udp_offload_priv *ou_priv = container_of(head, struct udp_offload_priv, rcu);
-	kfree(ou_priv);
-}
-
-void udp_del_offload(struct udp_offload *uo)
-{
-	struct udp_offload_priv __rcu **head = &udp_offload_base;
-	struct udp_offload_priv *uo_priv;
-
-	spin_lock(&udp_offload_lock);
-
-	uo_priv = udp_deref_protected(*head);
-	for (; uo_priv != NULL;
-	     uo_priv = udp_deref_protected(*head)) {
-		if (uo_priv->offload == uo) {
-			rcu_assign_pointer(*head,
-					   udp_deref_protected(uo_priv->next));
-			goto unlock;
-		}
-		head = &uo_priv->next;
-	}
-	pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo->port));
-unlock:
-	spin_unlock(&udp_offload_lock);
-	if (uo_priv)
-		call_rcu(&uo_priv->rcu, udp_offload_free_routine);
-}
-EXPORT_SYMBOL(udp_del_offload);
-
 struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
-				 struct udphdr *uh)
+				 struct udphdr *uh, udp_lookup_t lookup)
 {
-	struct udp_offload_priv *uo_priv;
 	struct sk_buff *p, **pp = NULL;
 	struct udphdr *uh2;
 	unsigned int off = skb_gro_offset(skb);
 	int flush = 1;
+	struct sock *sk;
 
 	if (NAPI_GRO_CB(skb)->encap_mark ||
 	    (skb->ip_summed != CHECKSUM_PARTIAL &&
@@ -322,13 +261,10 @@ struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
 	NAPI_GRO_CB(skb)->encap_mark = 1;
 
 	rcu_read_lock();
-	uo_priv = rcu_dereference(udp_offload_base);
-	for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
-		if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) &&
-		    uo_priv->offload->port == uh->dest &&
-		    uo_priv->offload->callbacks.gro_receive)
-			goto unflush;
-	}
+	sk = (*lookup)(skb, uh->source, uh->dest);
+
+	if (sk && udp_sk(sk)->gro_receive)
+		goto unflush;
 	goto out_unlock;
 
 unflush:
@@ -352,9 +288,7 @@ unflush:
 
 	skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
 	skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
-	NAPI_GRO_CB(skb)->proto = uo_priv->offload->ipproto;
-	pp = uo_priv->offload->callbacks.gro_receive(head, skb,
-						     uo_priv->offload);
+	pp = udp_sk(sk)->gro_receive(sk, head, skb);
 
 out_unlock:
 	rcu_read_unlock();
@@ -362,6 +296,7 @@ out:
 	NAPI_GRO_CB(skb)->flush |= flush;
 	return pp;
 }
+EXPORT_SYMBOL(udp_gro_receive);
 
 static struct sk_buff **udp4_gro_receive(struct sk_buff **head,
 					 struct sk_buff *skb)
@@ -383,39 +318,28 @@ static struct sk_buff **udp4_gro_receive(struct sk_buff **head,
 					     inet_gro_compute_pseudo);
 skip:
 	NAPI_GRO_CB(skb)->is_ipv6 = 0;
-	return udp_gro_receive(head, skb, uh);
+	return udp_gro_receive(head, skb, uh, udp4_lib_lookup_skb);
 
 flush:
 	NAPI_GRO_CB(skb)->flush = 1;
 	return NULL;
 }
 
-int udp_gro_complete(struct sk_buff *skb, int nhoff)
+int udp_gro_complete(struct sk_buff *skb, int nhoff,
+		     udp_lookup_t lookup)
 {
-	struct udp_offload_priv *uo_priv;
 	__be16 newlen = htons(skb->len - nhoff);
 	struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
 	int err = -ENOSYS;
+	struct sock *sk;
 
 	uh->len = newlen;
 
 	rcu_read_lock();
-
-	uo_priv = rcu_dereference(udp_offload_base);
-	for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
-		if (net_eq(read_pnet(&uo_priv->net), dev_net(skb->dev)) &&
-		    uo_priv->offload->port == uh->dest &&
-		    uo_priv->offload->callbacks.gro_complete)
-			break;
-	}
-
-	if (uo_priv) {
-		NAPI_GRO_CB(skb)->proto = uo_priv->offload->ipproto;
-		err = uo_priv->offload->callbacks.gro_complete(skb,
-				nhoff + sizeof(struct udphdr),
-				uo_priv->offload);
-	}
-
+	sk = (*lookup)(skb, uh->source, uh->dest);
+	if (sk && udp_sk(sk)->gro_complete)
+		err = udp_sk(sk)->gro_complete(sk, skb,
+				nhoff + sizeof(struct udphdr));
 	rcu_read_unlock();
 
 	if (skb->remcsum_offload)
@@ -426,6 +350,7 @@ int udp_gro_complete(struct sk_buff *skb, int nhoff)
 
 	return err;
 }
+EXPORT_SYMBOL(udp_gro_complete);
 
 static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
 {
@@ -440,7 +365,7 @@ static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
 		skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
 	}
 
-	return udp_gro_complete(skb, nhoff);
+	return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb);
 }
 
 static const struct net_offload udpv4_offload = {