This is a small cleanup, just to avoid duplicating the whole function
for v4 and v6 while the only difference between the two is one call to a
different send_synack() function.

Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
---
 net/mptcp/subflow.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 05099b3760b5..2ff3840fc058 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -307,12 +307,9 @@ static struct dst_entry *subflow_v4_route_req(const struct sock *sk,
 	return NULL;
 }
 
-static int subflow_v4_send_synack(const struct sock *sk, struct dst_entry *dst,
-				  struct flowi *fl,
-				  struct request_sock *req,
-				  struct tcp_fastopen_cookie *foc,
-				  enum tcp_synack_type synack_type,
-				  struct sk_buff *syn_skb)
+static void subflow_send_synack(const struct sock *sk, struct request_sock *req,
+				struct tcp_fastopen_cookie *foc,
+				enum tcp_synack_type synack_type)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 	struct inet_request_sock *ireq = inet_rsk(req);
@@ -323,8 +320,19 @@ static int subflow_v4_send_synack(const struct sock *sk, struct dst_entry *dst,
 
 	if (synack_type == TCP_SYNACK_FASTOPEN)
 		mptcp_fastopen_subflow_synack_set_params(subflow, req);
+}
+
+static int subflow_v4_send_synack(const struct sock *sk, struct dst_entry *dst,
+				  struct flowi *fl,
+				  struct request_sock *req,
+				  struct tcp_fastopen_cookie *foc,
+				  enum tcp_synack_type synack_type,
+				  struct sk_buff *syn_skb)
+{
+	subflow_send_synack(sk, req, foc, synack_type);
 
-	return tcp_request_sock_ipv4_ops.send_synack(sk, dst, fl, req, foc, synack_type, syn_skb);
+	return tcp_request_sock_ipv4_ops.send_synack(sk, dst, fl, req, foc,
+						     synack_type, syn_skb);
 }
 
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
@@ -335,17 +343,10 @@ static int subflow_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 				  enum tcp_synack_type synack_type,
 				  struct sk_buff *syn_skb)
 {
-	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
-	struct inet_request_sock *ireq = inet_rsk(req);
-
-	/* clear tstamp_ok, as needed depending on cookie */
-	if (foc && foc->len > -1)
-		ireq->tstamp_ok = 0;
-
-	if (synack_type == TCP_SYNACK_FASTOPEN)
-		mptcp_fastopen_subflow_synack_set_params(subflow, req);
+	subflow_send_synack(sk, req, foc, synack_type);
 
-	return tcp_request_sock_ipv6_ops.send_synack(sk, dst, fl, req, foc, synack_type, syn_skb);
+	return tcp_request_sock_ipv6_ops.send_synack(sk, dst, fl, req, foc,
+						     synack_type, syn_skb);
 }
 
 static struct dst_entry *subflow_v6_route_req(const struct sock *sk,

base-commit: 5d9ac522aceb69b5b524d330b6ecdbaff61decdc
-- 
2.37.2

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal:
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/6342328210685952
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/6342328210685952/summary/summary.txt

- KVM Validation: debug:
  - Unstable: 1 failed test(s): selftest_mptcp_join 🔴:
  - Task: https://cirrus-ci.com/task/4934953327132672
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/4934953327132672/summary/summary.txt

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/bfd8d2dba6d0


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-debug

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (Tessares)

Hello,

On 25/11/2022 22:20, Matthieu Baerts wrote:
> This is a small cleanup, just to avoid duplicating the whole function
> for v4 and v6 while the only difference between the two is one call to a
> different send_synack() function.
> 
> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> ---
>  net/mptcp/subflow.c | 35 ++++++++++++++++++-----------------
>  1 file changed, 18 insertions(+), 17 deletions(-)
> 
> diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
> index 05099b3760b5..2ff3840fc058 100644
> --- a/net/mptcp/subflow.c
> +++ b/net/mptcp/subflow.c
> @@ -307,12 +307,9 @@ static struct dst_entry *subflow_v4_route_req(const struct sock *sk,
>  	return NULL;
>  }
>  
> -static int subflow_v4_send_synack(const struct sock *sk, struct dst_entry *dst,
> -				  struct flowi *fl,
> -				  struct request_sock *req,
> -				  struct tcp_fastopen_cookie *foc,
> -				  enum tcp_synack_type synack_type,
> -				  struct sk_buff *syn_skb)
> +static void subflow_send_synack(const struct sock *sk, struct request_sock *req,

I just applied this patch with a small change:

    s/subflow_send_synack/subflow_prep_synack/

- 61e817662ce3: "squashed" in "mptcp: add subflow_v(4,6)_send_synack()"
- Results: 2deca8211919..ace83548981f (export)

Tests are now in progress:

https://cirrus-ci.com/github/multipath-tcp/mptcp_net-next/export/20221125T222831

Cheers,
Matt
-- 
Tessares | Belgium | Hybrid Access Solutions
www.tessares.net