Merge branch 'mptcp-sdeq-fixes'

Mat Martineau says:

====================
mptcp: 32-bit sequence number improvements

MPTCP-level sequence numbers are 64 bits, but RFC 8684 allows use of
32-bit sequence numbers in the DSS option to save header space. Those
32-bit numbers are the least significant bits of the full 64-bit
sequence number, so the receiver must infer the correct upper 32 bits.

These two patches improve the logic for determining the full 64-bit
sequence numbers when the 32-bit truncated version has wrapped around.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 385796f0ef19..5d7c44028e47 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -593,6 +593,14 @@ int mptcp_setsockopt(struct sock *sk, int level, int optname,
 int mptcp_getsockopt(struct sock *sk, int level, int optname,
 		     char __user *optval, int __user *option);
 
+u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
+static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
+{
+	if (use_64bit)
+		return cur_seq;
+
+	return __mptcp_expand_seq(old_seq, cur_seq);
+}
 void __mptcp_check_push(struct sock *sk, struct sock *ssk);
 void __mptcp_data_acked(struct sock *sk);
 void __mptcp_error_report(struct sock *sk);