[PATCH v3 mptcp-next 1/3] Squash-to: "mptcp: move drop_other_suboptions check under pm lock"

[Paolo Abeni <pabeni@redhat.com>]

Commit message to be updated appending:

"""
Additionally, always drop the other suboption for TCP pure ack:
that makes both the code simpler and the MPTCP behaviour more
consistent.
"""


Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/mptcp/pm.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 4d1828fd2482..cd2323e5ccdc 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -266,10 +266,11 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb,
 	if (!mptcp_pm_should_add_signal(msk))
 		goto out_unlock;
 
-	if (((msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_ECHO)) ||
-	     ((msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL)) &&
-	      (msk->pm.local.family == AF_INET6 || msk->pm.local.port))) &&
-	    skb && skb_is_tcp_pure_ack(skb)) {
+	/* always drop every other options for pure ack ADD_ADDR; this is a
+	 * plain dup-ack from TCP perspective. The other MPTCP-relevant info,
+	 * if any, will be carried by the 'original' TCP ack
+	 */
+	if (skb && skb_is_tcp_pure_ack(skb)) {
 		remaining += opt_size;
 		*drop_other_suboptions = true;
 	}
-- 
2.26.3