diff mbox series

[mptcp-net,3/4] mptcp: fix more tx path fields initialization

Message ID 2ebb639a44ec33784f79c0b2dcdfc688d3afb868.1705331716.git.pabeni@redhat.com (mailing list archive)
State Accepted, archived
Commit a6f5bfc5abf70ade9a64cd51963d563f19d6d339
Delegated to: Matthieu Baerts
Headers show
Series mptcp: locking cleanup | expand

Checks

Context Check Description
matttbe/checkpatch success total: 0 errors, 0 warnings, 0 checks, 35 lines checked
matttbe/build success Build and static analysis OK
matttbe/KVM_Validation__debug__except_selftest_mptcp_join_ warning Unstable: 1 failed test(s): selftest_diag
matttbe/KVM_Validation__debug__only_selftest_mptcp_join_ success Success! ✅
matttbe/KVM_Validation__normal warning Unstable: 2 failed test(s): packetdrill_regressions selftest_mptcp_join

Commit Message

Paolo Abeni Jan. 15, 2024, 3:16 p.m. UTC 
The 'msk->write_seq' and 'msk->snd_nxt' are always updated under
the msk socket lock, except at MPC handshake completiont time.

Builds-up on the previous commit to move such init under the relevant
lock.

There are no known problems caused by the potential race, the
primary goal is consistency.

Fixes: 6d0060f600ad ("mptcp: Write MPTCP DSS headers to outgoing data packets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/mptcp/protocol.c |  6 ++----
 net/mptcp/subflow.c  | 13 +++++++++++--
 2 files changed, 13 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index c41f49532a0a..b7d1da7bcb50 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3481,10 +3481,8 @@  void mptcp_finish_connect(struct sock *ssk)
 	 * accessing the field below
 	 */
 	WRITE_ONCE(msk->local_key, subflow->local_key);
-	WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
-	WRITE_ONCE(msk->snd_nxt, msk->write_seq);
-	WRITE_ONCE(msk->snd_una, msk->write_seq);
-	WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);
+	WRITE_ONCE(msk->snd_una, subflow->idsn + 1);
+	WRITE_ONCE(msk->wnd_end, subflow->idsn + 1 + tcp_sk(ssk)->snd_wnd);
 
 	mptcp_pm_new_connection(msk, ssk, 0);
 }
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 23f639e0d8c3..fe5334cee477 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -421,12 +421,21 @@  static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct soc
 
 void __mptcp_sync_state(struct sock *sk, int state)
 {
+	struct mptcp_subflow_context *subflow;
 	struct mptcp_sock *msk = mptcp_sk(sk);
+	struct sock *ssk = msk->first;
 
-	__mptcp_propagate_sndbuf(sk, msk->first);
+	subflow = mptcp_subflow_ctx(ssk);
+	__mptcp_propagate_sndbuf(sk, ssk);
 	if (!msk->rcvspace_init)
-		mptcp_rcv_space_init(msk, msk->first);
+		mptcp_rcv_space_init(msk, ssk);
+
 	if (sk->sk_state == TCP_SYN_SENT) {
+		/* subflow->idsn is always available is TCP_SYN_SENT state,
+		 * even for the FASTOPEN scenarios
+		 */
+		WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
+		WRITE_ONCE(msk->snd_nxt, msk->write_seq);
 		mptcp_set_state(sk, state);
 		sk->sk_state_change(sk);
 	}