tcp: export timestamp helpers for mptcp

MPTCP is builtin, so no need to add EXPORT_SYMBOL()s.

It will be used to support SO_TIMESTAMP(NS) ancillary
messages in the mptcp receive path.
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tcp.h

@@ -412,6 +412,10 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 		int flags, int *addr_len);
 int tcp_set_rcvlowat(struct sock *sk, int val);
 int tcp_set_window_clamp(struct sock *sk, int val);
+void tcp_update_recv_tstamps(struct sk_buff *skb,
+			     struct scm_timestamping_internal *tss);
+void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
+			struct scm_timestamping_internal *tss);
 void tcp_data_ready(struct sock *sk);
 #ifdef CONFIG_MMU
 int tcp_mmap(struct file *file, struct socket *sock,

net/ipv4/tcp.c

@@ -1738,8 +1738,8 @@ int tcp_set_rcvlowat(struct sock *sk, int val)
 }
 EXPORT_SYMBOL(tcp_set_rcvlowat);
 
-static void tcp_update_recv_tstamps(struct sk_buff *skb,
-				    struct scm_timestamping_internal *tss)
+void tcp_update_recv_tstamps(struct sk_buff *skb,
+			     struct scm_timestamping_internal *tss)
 {
 	if (skb->tstamp)
 		tss->ts[0] = ktime_to_timespec64(skb->tstamp);
@@ -2024,8 +2024,6 @@ static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma,
 }
 
 #define TCP_VALID_ZC_MSG_FLAGS   (TCP_CMSG_TS)
-static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
-			       struct scm_timestamping_internal *tss);
 static void tcp_zc_finalize_rx_tstamp(struct sock *sk,
 				      struct tcp_zerocopy_receive *zc,
 				      struct scm_timestamping_internal *tss)
@@ -2197,8 +2195,8 @@ static int tcp_zerocopy_receive(struct sock *sk,
 #endif
 
 /* Similar to __sock_recv_timestamp, but does not require an skb */
-static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
-			       struct scm_timestamping_internal *tss)
+void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
+			struct scm_timestamping_internal *tss)
 {
 	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
 	bool has_timestamping = false;