Merge branch 'mptcp-various-fixes'

Matthieu Baerts says:

====================
mptcp: various fixes

The different patches here are some unrelated fixes for MPTCP:

- Patch 1 ensures 'snd_una' is initialised on connect in case of MPTCP
  fallback to TCP followed by retransmissions before the processing of
  any other incoming packets. A fix for v5.9+.

- Patch 2 makes sure the RmAddr MIB counter is incremented, and only
  once per ID, upon the reception of a RM_ADDR. A fix for v5.10+.

- Patch 3 doesn't update 'add addr' related counters if the connect()
  was not possible. A fix for v5.7+.

- Patch 4 updates the mailmap file to add Geliang's new email address.
====================

Link: https://lore.kernel.org/r/20240607-upstream-net-20240607-misc-fixes-v1-0-1ab9ddfa3d00@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 15 insertions, 7 deletions

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 7f53e022e27e..ea9e5817b9e9 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -677,6 +677,7 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 	unsigned int add_addr_accept_max;
 	struct mptcp_addr_info remote;
 	unsigned int subflows_max;
+	bool sf_created = false;
 	int i, nr;
 
 	add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
@@ -704,15 +705,18 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 	if (nr == 0)
 		return;
 
-	msk->pm.add_addr_accepted++;
-	if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
-	    msk->pm.subflows >= subflows_max)
-		WRITE_ONCE(msk->pm.accept_addr, false);
-
 	spin_unlock_bh(&msk->pm.lock);
 	for (i = 0; i < nr; i++)
-		__mptcp_subflow_connect(sk, &addrs[i], &remote);
+		if (__mptcp_subflow_connect(sk, &addrs[i], &remote) == 0)
+			sf_created = true;
 	spin_lock_bh(&msk->pm.lock);
+
+	if (sf_created) {
+		msk->pm.add_addr_accepted++;
+		if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
+		    msk->pm.subflows >= subflows_max)
+			WRITE_ONCE(msk->pm.accept_addr, false);
+	}
 }
 
 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
@@ -814,10 +818,13 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 			spin_lock_bh(&msk->pm.lock);
 
 			removed = true;
-			__MPTCP_INC_STATS(sock_net(sk), rm_type);
+			if (rm_type == MPTCP_MIB_RMSUBFLOW)
+				__MPTCP_INC_STATS(sock_net(sk), rm_type);
 		}
 		if (rm_type == MPTCP_MIB_RMSUBFLOW)
 			__set_bit(rm_id ? rm_id : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap);
+		else if (rm_type == MPTCP_MIB_RMADDR)
+			__MPTCP_INC_STATS(sock_net(sk), rm_type);
 		if (!removed)
 			continue;
 
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 96b113854bd3..bb7dca8aa2d9 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3740,6 +3740,7 @@ static int mptcp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 
 	WRITE_ONCE(msk->write_seq, subflow->idsn);
 	WRITE_ONCE(msk->snd_nxt, subflow->idsn);
+	WRITE_ONCE(msk->snd_una, subflow->idsn);
 	if (likely(!__mptcp_check_fallback(msk)))
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVE);