ipv6: use indirect call wrappers for {tcp, udpv6}_{recv, send}msg()

This avoids an indirect call per syscall for common ipv6 transports
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/af_inet6.c

@@ -564,6 +564,8 @@ int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 }
 EXPORT_SYMBOL(inet6_ioctl);
 
+INDIRECT_CALLABLE_DECLARE(int udpv6_sendmsg(struct sock *, struct msghdr *,
+					    size_t));
 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 {
 	struct sock *sk = sock->sk;
@@ -571,9 +573,12 @@ int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 	if (unlikely(inet_send_prepare(sk)))
 		return -EAGAIN;
 
-	return sk->sk_prot->sendmsg(sk, msg, size);
+	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udpv6_sendmsg,
+			       sk, msg, size);
 }
 
+INDIRECT_CALLABLE_DECLARE(int udpv6_recvmsg(struct sock *, struct msghdr *,
+					    size_t, int, int, int *));
 int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		  int flags)
 {
@@ -584,8 +589,9 @@ int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	if (likely(!(flags & MSG_ERRQUEUE)))
 		sock_rps_record_flow(sk);
 
-	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
-				   flags & ~MSG_DONTWAIT, &addr_len);
+	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udpv6_recvmsg,
+			      sk, msg, size, flags & MSG_DONTWAIT,
+			      flags & ~MSG_DONTWAIT, &addr_len);
 	if (err >= 0)
 		msg->msg_namelen = addr_len;
 	return err;