udp: move gro declarations to net/udp.h

This removes following warnings :
  CC      net/ipv4/udp_offload.o
net/ipv4/udp_offload.c:504:17: warning: no previous prototype for 'udp4_gro_receive' [-Wmissing-prototypes]
  504 | struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb)
      |                 ^~~~~~~~~~~~~~~~
net/ipv4/udp_offload.c:584:29: warning: no previous prototype for 'udp4_gro_complete' [-Wmissing-prototypes]
  584 | INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff)
      |                             ^~~~~~~~~~~~~~~~~

  CHECK   net/ipv6/udp_offload.c
net/ipv6/udp_offload.c:115:16: warning: symbol 'udp6_gro_receive' was not declared. Should it be static?
net/ipv6/udp_offload.c:148:29: warning: symbol 'udp6_gro_complete' was not declared. Should it be static?
  CC      net/ipv6/udp_offload.o
net/ipv6/udp_offload.c:115:17: warning: no previous prototype for 'udp6_gro_receive' [-Wmissing-prototypes]
  115 | struct sk_buff *udp6_gro_receive(struct list_head *head, struct sk_buff *skb)
      |                 ^~~~~~~~~~~~~~~~
net/ipv6/udp_offload.c:148:29: warning: no previous prototype for 'udp6_gro_complete' [-Wmissing-prototypes]
  148 | INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff)
      |                             ^~~~~~~~~~~~~~~~~
Signed-off-by: Eric Dumazet <edumazet@google.com>

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

include/net/udp.h

@@ -27,6 +27,7 @@
 #include <linux/ipv6.h>
 #include <linux/seq_file.h>
 #include <linux/poll.h>
+#include <linux/indirect_call_wrapper.h>
 
 /**
  *	struct udp_skb_cb  -  UDP(-Lite) private variables
@@ -166,6 +167,12 @@ static inline void udp_csum_pull_header(struct sk_buff *skb)
 typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport,
 				     __be16 dport);
 
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
+							   struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
+							   struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));
 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
 				struct udphdr *uh, struct sock *sk);
 int udp_gro_complete(struct sk_buff *skb, int nhoff, udp_lookup_t lookup);

net/ipv4/af_inet.c

@@ -1432,8 +1432,6 @@ static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
 	return inet_gso_segment(skb, features);
 }
 
-INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
-							   struct sk_buff *));
 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
 {
 	const struct net_offload *ops;
@@ -1606,7 +1604,6 @@ int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 	return -EINVAL;
 }
 
-INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
 int inet_gro_complete(struct sk_buff *skb, int nhoff)
 {
 	__be16 newlen = htons(skb->len - nhoff);

net/ipv6/ip6_offload.c

@@ -14,6 +14,7 @@
 #include <net/ipv6.h>
 #include <net/inet_common.h>
 #include <net/tcp.h>
+#include <net/udp.h>
 
 #include "ip6_offload.h"
 
@@ -178,8 +179,6 @@ static int ipv6_exthdrs_len(struct ipv6hdr *iph,
 	return len;
 }
 
-INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp6_gro_receive(struct list_head *,
-							   struct sk_buff *));
 INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
 							 struct sk_buff *skb)
 {
@@ -318,7 +317,6 @@ static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
 	return inet_gro_receive(head, skb);
 }
 
-INDIRECT_CALLABLE_DECLARE(int udp6_gro_complete(struct sk_buff *, int));
 INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
 {
 	const struct net_offload *ops;