On Mon, Mar 9, 2026 at 9:03 AM Simon Baatz via B4 Relay <[email protected]> wrote: > > From: Simon Baatz <[email protected]> > > This test verifies > - the sequence number checks using the maximum advertised window > sequence number and > - the logic for handling received data in tcp_data_queue() > > for the cases: > > 1. The window is reduced to zero because of memory > > 2. The window grows again but still does not reach the originally > advertised window > > Signed-off-by: Simon Baatz <[email protected]> > ---
Reviewed-by: Eric Dumazet <[email protected]> Thanks ! > +// Ooo partial segment, in adv. window -> accept > + +0 < P. 1040001:1042001(2000) ack 2001 win 257 > + +0 > . 2001:2001(0) ack 1042001 <nop,nop,sack 1040001:1041001> > + > +// Ooo segment, in max adv. window, beyond adv. window -> drop > (SKB_DROP_REASON_TCP_OVERWINDOW) > + +0 < P. 1105001:1106001(1000) ack 2001 win 257 > + +0 > . 2001:2001(0) ack 1042001 > +// Ooo segment, beyond max adv. window, beyond adv. window -> drop > (SKB_DROP_REASON_TCP_INVALID_SEQUENCE) > + +0 < P. 2000001:2001001(1000) ack 2001 win 257 > + +0 > . 2001:2001(0) ack 1042001 > +// Check LINUX_MIB_BEYOND_WINDOW has been incremented twice > + +0 `nstat -s | grep TcpExtBeyondWindow | grep -q " 4 "` > + > +// We are allowed to go beyond the window and buffer with one packet > + +0 < P. 1042001:1062001(20000) ack 2001 win 257 > + * > . 2001:2001(0) ack 1062001 > + +0 < P. 1062001:1082001(20000) ack 2001 win 257 > + * > . 2001:2001(0) ack 1082001 win 0 > + > +// But not more: In order segment, in max adv. window -> drop > (SKB_DROP_REASON_TCP_ZEROWINDOW) > + +0 < P. 1082001:1083001(1000) ack 2001 win 257 > + * > . 2001:2001(0) ack 1082001 > +// Check LINUX_MIB_TCPZEROWINDOWDROP has been incremented again > + +0 `nstat -s | grep TcpExtTCPZeroWindowDrop| grep -q " 3 "` > > -- > 2.53.0 > >
