net: indirect call helpers for ipv4/ipv6 dst_check functions

This patch avoids the indirect call for the common case:
ip6_dst_check and ipv4_dst_check

Signed-off-by: Brian Vazquez <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

include/net/dst.h

···
 				  ip6_input, ip_local_deliver, skb);
 }
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
+							  u32));
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
 {
 	if (dst->obsolete)
-		dst = dst->ops->check(dst, cookie);
+		dst = INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check,
+					 ipv4_dst_check, dst, cookie);
 	return dst;
 }
 

net/core/sock.c

···
 }
 EXPORT_SYMBOL(__sk_receive_skb);
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
+							  u32));
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
 {
 	struct dst_entry *dst = __sk_dst_get(sk);
 
-	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+	if (dst && dst->obsolete &&
+	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
+			       dst, cookie) == NULL) {
 		sk_tx_queue_clear(sk);
 		sk->sk_dst_pending_confirm = 0;
 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
···
 {
 	struct dst_entry *dst = sk_dst_get(sk);
 
-	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+	if (dst && dst->obsolete &&
+	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
+			       dst, cookie) == NULL) {
 		sk_dst_reset(sk);
 		dst_release(dst);
 		return NULL;

net/ipv4/route.c

···
  *	Interface to generic destination cache.
  */
 
-static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
+INDIRECT_CALLABLE_SCOPE
+struct dst_entry	*ipv4_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ipv4_default_advmss(const struct dst_entry *dst);
 INDIRECT_CALLABLE_SCOPE
 unsigned int		ipv4_mtu(const struct dst_entry *dst);
···
 }
 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
 
-static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
+INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst,
+							 u32 cookie)
 {
 	struct rtable *rt = (struct rtable *) dst;
 
···
 		return NULL;
 	return dst;
 }
+EXPORT_SYMBOL(ipv4_dst_check);
 
 static void ipv4_send_dest_unreach(struct sk_buff *skb)
 {

net/ipv4/tcp_ipv4.c

···
 	return mss;
 }
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 /* The socket must have it's spinlock held when we get
  * here, unless it is a TCP_LISTEN socket.
  *
···
 		sk_mark_napi_id(sk, skb);
 		if (dst) {
 			if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
-			    !dst->ops->check(dst, 0)) {
+			    !INDIRECT_CALL_1(dst->ops->check, ipv4_dst_check,
+					     dst, 0)) {
 				dst_release(dst);
 				sk->sk_rx_dst = NULL;
 			}

net/ipv6/route.c

···
 	RT6_NUD_SUCCEED = 1
 };
 
-static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
+INDIRECT_CALLABLE_SCOPE
+struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
 INDIRECT_CALLABLE_SCOPE
 unsigned int		ip6_mtu(const struct dst_entry *dst);
···
 		return NULL;
 }
 
-static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
+INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
+							u32 cookie)
 {
 	struct dst_entry *dst_ret;
 	struct fib6_info *from;
···
 
 	return dst_ret;
 }
+EXPORT_SYMBOL(ip6_dst_check);
 
 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
 {

net/ipv6/tcp_ipv6.c

···
 	return NULL;
 }
 
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+							   u32));
 /* The socket must have it's spinlock held when we get
  * here, unless it is a TCP_LISTEN socket.
  *
···
 		sk_mark_napi_id(sk, skb);
 		if (dst) {
 			if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
-			    dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
+			    INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
+					    dst, np->rx_dst_cookie) == NULL) {
 				dst_release(dst);
 				sk->sk_rx_dst = NULL;
 			}