[PATCH net-next 1/3] selftests: packetdrill: stop pinning rwnd in tcp_ooo_rcv_mss

From: Wesley Atwell

Date: Tue Mar 17 2026 - 02:54:21 EST


tcp_ooo_rcv_mss.pkt cares about the OOO SACK state and the resulting
tcpi_rcv_mss update.

Its exact advertised receive-window value is incidental to that test and
can legitimately move when unrelated rwnd accounting changes adjust the
ACK window.

Drop the hard-coded win 81 checks and keep only the ACK/SACK shape and
the tcpi_rcv_mss assertion.

Signed-off-by: Wesley Atwell <atwellwea@xxxxxxxxx>
---
tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt b/tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt
index 7e6bc5fb0c8d78f36dc3d18842ff11d938c4e41b..0b19de9f9307b3d0ee579bc9e3a2b9219a88cd8a 100644
--- a/tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt
+++ b/tools/testing/selftests/net/packetdrill/tcp_ooo_rcv_mss.pkt
@@ -17,11 +17,13 @@ sysctl -q net.ipv4.tcp_rmem="4096 131072 $((32*1024*1024))"`
+0 accept(3, ..., ...) = 4

+0 < . 2001:11001(9000) ack 1 win 257
- +0 > . 1:1(0) ack 1 win 81 <nop,nop,sack 2001:11001>
+// This test cares about the OOO SACK state and the resulting tcpi_rcv_mss.
+// Keep the ACK/SACK shape exact, but do not pin the precise advertised
+// receive window here because unrelated rwnd accounting changes can adjust it.
+ +0 > . 1:1(0) ack 1 <nop,nop,sack 2001:11001>

// check that ooo packet properly updates tcpi_rcv_mss
+0 %{ assert tcpi_rcv_mss == 1000, tcpi_rcv_mss }%

+0 < . 11001:21001(10000) ack 1 win 257
- +0 > . 1:1(0) ack 1 win 81 <nop,nop,sack 2001:21001>
-
+ +0 > . 1:1(0) ack 1 <nop,nop,sack 2001:21001>
--
2.43.0