[PATCH net-next v3 5/6] mptcp: support rstreason for passive reset

[Jason Xing]

From: Jason Xing <kernelx...@tencent.com>

It relys on what reset options in the skb are as rfc8684 says. Reusing
this logic can save us much energy. This patch replaces most of the prior
NOT_SPECIFIED reasons.

Signed-off-by: Jason Xing <kernelx...@tencent.com>
---
 net/mptcp/subflow.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index ba0a252c113f..4f2be72d5b02 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -308,8 +308,11 @@ static struct dst_entry *subflow_v4_route_req(const struct 
sock *sk,
                return dst;
 
        dst_release(dst);
-       if (!req->syncookie)
-               tcp_request_sock_ops.send_reset(sk, skb, 
SK_RST_REASON_NOT_SPECIFIED);
+       if (!req->syncookie) {
+               struct mptcp_ext *mpext = mptcp_get_ext(skb);
+
+               tcp_request_sock_ops.send_reset(sk, skb, mpext->reset_reason);
+       }
        return NULL;
 }
 
@@ -375,8 +378,11 @@ static struct dst_entry *subflow_v6_route_req(const struct 
sock *sk,
                return dst;
 
        dst_release(dst);
-       if (!req->syncookie)
-               tcp6_request_sock_ops.send_reset(sk, skb, 
SK_RST_REASON_NOT_SPECIFIED);
+       if (!req->syncookie) {
+               struct mptcp_ext *mpext = mptcp_get_ext(skb);
+
+               tcp6_request_sock_ops.send_reset(sk, skb, mpext->reset_reason);
+       }
        return NULL;
 }
 #endif
@@ -783,6 +789,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock 
*sk,
        bool fallback, fallback_is_fatal;
        struct mptcp_sock *owner;
        struct sock *child;
+       int reason;
 
        pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn);
 
@@ -911,7 +918,8 @@ static struct sock *subflow_syn_recv_sock(const struct sock 
*sk,
        tcp_rsk(req)->drop_req = true;
        inet_csk_prepare_for_destroy_sock(child);
        tcp_done(child);
-       req->rsk_ops->send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED);
+       reason = mptcp_get_ext(skb)->reset_reason;
+       req->rsk_ops->send_reset(sk, skb, convert_mptcp_reason(reason));
 
        /* The last child reference will be released by the caller */
        return child;
-- 
2.37.3