diff mbox series

[mptcp-next,v9,5/6] mptcp: establish subflows from either end of connection

Message ID 20220329021401.1196466-6-kishen.maloor@intel.com (mailing list archive)
State Accepted, archived
Commit 12d4f5bc7b1c06ec96abcc4e7d793739bbb2af1f
Delegated to: Matthieu Baerts
Headers show
Series mptcp: fixes and enhancements related to path management | expand

Checks

Context Check Description
matttbe/checkpatch success total: 0 errors, 0 warnings, 0 checks, 43 lines checked
matttbe/build warning Build error with: make C=1 net/mptcp/bpf.o
matttbe/KVM_Validation__normal warning Unstable: 1 failed test(s): selftest_mptcp_join
matttbe/KVM_Validation__debug warning Unstable: 2 failed test(s): selftest_mptcp_join selftest_simult_flows

Commit Message

Kishen Maloor March 29, 2022, 2:14 a.m. UTC
This change updates internal logic to permit subflows to be
established from either the client or server ends of MPTCP
connections. This symmetry and added flexibility may be
harnessed by PM implementations running on either end in
creating new subflows.

The essence of this change lies in not relying on the
"server_side" flag (which continues to be available if needed).

Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
---
 net/mptcp/options.c  | 2 +-
 net/mptcp/protocol.c | 5 +----
 net/mptcp/protocol.h | 8 ++++++--
 3 files changed, 8 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index c9625fea3ef9..e05d9458a025 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -931,7 +931,7 @@  static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk,
 		if (TCP_SKB_CB(skb)->seq == subflow->ssn_offset + 1 &&
 		    TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq &&
 		    subflow->mp_join && (mp_opt->suboptions & OPTIONS_MPTCP_MPJ) &&
-		    READ_ONCE(msk->pm.server_side))
+		    !subflow->request_join)
 			tcp_send_ack(ssk);
 		goto fully_established;
 	}
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index d3887f628b54..b2c654992de0 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3327,15 +3327,12 @@  bool mptcp_finish_join(struct sock *ssk)
 		return false;
 	}
 
-	if (!msk->pm.server_side)
+	if (!list_empty(&subflow->node))
 		goto out;
 
 	if (!mptcp_pm_allow_new_subflow(msk))
 		goto err_prohibited;
 
-	if (WARN_ON_ONCE(!list_empty(&subflow->node)))
-		goto err_prohibited;
-
 	/* active connections are already on conn_list.
 	 * If we can't acquire msk socket lock here, let the release callback
 	 * handle it
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index a762b789f5ab..187c932deef0 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -911,13 +911,17 @@  static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
 	return false;
 }
 
+static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
+{
+	return (subflow->request_mptcp || subflow->request_join);
+}
+
 static inline bool subflow_simultaneous_connect(struct sock *sk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
-	struct sock *parent = subflow->conn;
 
 	return sk->sk_state == TCP_ESTABLISHED &&
-	       !mptcp_sk(parent)->pm.server_side &&
+	       is_active_ssk(subflow) &&
 	       !subflow->conn_finished;
 }