udp: expose inet cork to udp

UDP segmentation offload needs access to inet_cork in the udp layer.
Pass the struct to ip(6)_make_skb instead of allocating it on the
stack in that function itself.

This patch is a noop otherwise.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -171,7 +171,7 @@ struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
 					int len, int odd, struct sk_buff *skb),
 			    void *from, int length, int transhdrlen,
 			    struct ipcm_cookie *ipc, struct rtable **rtp,
-			    unsigned int flags);
+			    struct inet_cork *cork, unsigned int flags);
 
 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
 {

include/net/ipv6.h

@@ -950,6 +950,7 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 			     void *from, int length, int transhdrlen,
 			     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
 			     struct rt6_info *rt, unsigned int flags,
+			     struct inet_cork_full *cork,
 			     const struct sockcm_cookie *sockc);
 
 static inline struct sk_buff *ip6_finish_skb(struct sock *sk)

net/ipv4/ip_output.c

@@ -1470,9 +1470,8 @@ struct sk_buff *ip_make_skb(struct sock *sk,
 					int len, int odd, struct sk_buff *skb),
 			    void *from, int length, int transhdrlen,
 			    struct ipcm_cookie *ipc, struct rtable **rtp,
-			    unsigned int flags)
+			    struct inet_cork *cork, unsigned int flags)
 {
-	struct inet_cork cork;
 	struct sk_buff_head queue;
 	int err;
 
@@ -1481,22 +1480,22 @@ struct sk_buff *ip_make_skb(struct sock *sk,
 
 	__skb_queue_head_init(&queue);
 
-	cork.flags = 0;
-	cork.addr = 0;
-	cork.opt = NULL;
-	err = ip_setup_cork(sk, &cork, ipc, rtp);
+	cork->flags = 0;
+	cork->addr = 0;
+	cork->opt = NULL;
+	err = ip_setup_cork(sk, cork, ipc, rtp);
 	if (err)
 		return ERR_PTR(err);
 
-	err = __ip_append_data(sk, fl4, &queue, &cork,
+	err = __ip_append_data(sk, fl4, &queue, cork,
 			       &current->task_frag, getfrag,
 			       from, length, transhdrlen, flags);
 	if (err) {
-		__ip_flush_pending_frames(sk, &queue, &cork);
+		__ip_flush_pending_frames(sk, &queue, cork);
 		return ERR_PTR(err);
 	}
 
-	return __ip_make_skb(sk, fl4, &queue, &cork);
+	return __ip_make_skb(sk, fl4, &queue, cork);
 }
 
 /*

net/ipv4/udp.c

@@ -1030,9 +1030,11 @@ back_from_confirm:
 
 	/* Lockless fast path for the non-corking case. */
 	if (!corkreq) {
+		struct inet_cork cork;
+
 		skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
 				  sizeof(struct udphdr), &ipc, &rt,
-				  msg->msg_flags);
+				  &cork, msg->msg_flags);
 		err = PTR_ERR(skb);
 		if (!IS_ERR_OR_NULL(skb))
 			err = udp_send_skb(skb, fl4);

net/ipv6/ip6_output.c

@@ -1755,9 +1755,9 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 			     void *from, int length, int transhdrlen,
 			     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
 			     struct rt6_info *rt, unsigned int flags,
+			     struct inet_cork_full *cork,
 			     const struct sockcm_cookie *sockc)
 {
-	struct inet_cork_full cork;
 	struct inet6_cork v6_cork;
 	struct sk_buff_head queue;
 	int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
@@ -1768,27 +1768,27 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 
 	__skb_queue_head_init(&queue);
 
-	cork.base.flags = 0;
-	cork.base.addr = 0;
-	cork.base.opt = NULL;
-	cork.base.dst = NULL;
+	cork->base.flags = 0;
+	cork->base.addr = 0;
+	cork->base.opt = NULL;
+	cork->base.dst = NULL;
 	v6_cork.opt = NULL;
-	err = ip6_setup_cork(sk, &cork, &v6_cork, ipc6, rt, fl6);
+	err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6);
 	if (err) {
-		ip6_cork_release(&cork, &v6_cork);
+		ip6_cork_release(cork, &v6_cork);
 		return ERR_PTR(err);
 	}
 	if (ipc6->dontfrag < 0)
 		ipc6->dontfrag = inet6_sk(sk)->dontfrag;
 
-	err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork,
+	err = __ip6_append_data(sk, fl6, &queue, &cork->base, &v6_cork,
 				&current->task_frag, getfrag, from,
 				length + exthdrlen, transhdrlen + exthdrlen,
 				flags, ipc6, sockc);
 	if (err) {
-		__ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork);
+		__ip6_flush_pending_frames(sk, &queue, cork, &v6_cork);
 		return ERR_PTR(err);
 	}
 
-	return __ip6_make_skb(sk, &queue, &cork, &v6_cork);
+	return __ip6_make_skb(sk, &queue, cork, &v6_cork);
 }

net/ipv6/udp.c

@@ -1324,12 +1324,13 @@ back_from_confirm:
 
 	/* Lockless fast path for the non-corking case */
 	if (!corkreq) {
+		struct inet_cork_full cork;
 		struct sk_buff *skb;
 
 		skb = ip6_make_skb(sk, getfrag, msg, ulen,
 				   sizeof(struct udphdr), &ipc6,
 				   &fl6, (struct rt6_info *)dst,
-				   msg->msg_flags, &sockc);
+				   msg->msg_flags, &cork, &sockc);
 		err = PTR_ERR(skb);
 		if (!IS_ERR_OR_NULL(skb))
 			err = udp_v6_send_skb(skb, &fl6);