tcp, ulp: Add clone operation to tcp_ulp_ops
If ULP is used on a listening socket, icsk_ulp_ops and icsk_ulp_data are
copied when the listener is cloned. Sometimes the clone is immediately
deleted, which will invoke the release op on the clone and likely
corrupt the listening socket's icsk_ulp_data.
The clone operation is invoked immediately after the clone is copied and
gives the ULP type an opportunity to set up the clone socket and its
icsk_ulp_data.
The MPTCP ULP clone will silently fallback to plain TCP on allocation
failure, so 'clone()' does not need to return an error code.
v6 -> v7:
- move and rename ulp clone helper to make it inline-friendly
v5 -> v6:
- clarified MPTCP clone usage in commit message
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 85f1d7f..ac52633 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2154,6 +2154,9 @@ struct tcp_ulp_ops {
/* diagnostic */
int (*get_info)(const struct sock *sk, struct sk_buff *skb);
size_t (*get_info_size)(const struct sock *sk);
+ /* clone ulp */
+ void (*clone)(const struct request_sock *req, struct sock *newsk,
+ const gfp_t priority);
char name[TCP_ULP_NAME_MAX];
struct module *owner;
