13eb371edSSimon Baatz// SPDX-License-Identifier: GPL-2.0 2*96a584dbSSimon Baatz// Test maximum advertised window limit when rcv_nxt advances past 3*96a584dbSSimon Baatz// rcv_mwnd_seq. The "usable window" must be properly clamped to zero 4*96a584dbSSimon Baatz// rather than becoming negative. 53eb371edSSimon Baatz 63eb371edSSimon Baatz--mss=1000 73eb371edSSimon Baatz 83eb371edSSimon Baatz`./defaults.sh` 93eb371edSSimon Baatz 103eb371edSSimon Baatz// Establish a connection. 113eb371edSSimon Baatz +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 123eb371edSSimon Baatz +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 133eb371edSSimon Baatz +0 setsockopt(3, SOL_SOCKET, SO_RCVBUF, [20000], 4) = 0 143eb371edSSimon Baatz +0 bind(3, ..., ...) = 0 153eb371edSSimon Baatz +0 listen(3, 1) = 0 163eb371edSSimon Baatz 173eb371edSSimon Baatz +0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7> 183eb371edSSimon Baatz +0 > S. 0:0(0) ack 1 win 18980 <mss 1460,nop,wscale 0> 193eb371edSSimon Baatz +.1 < . 1:1(0) ack 1 win 257 203eb371edSSimon Baatz 213eb371edSSimon Baatz +0 accept(3, ..., ...) = 4 223eb371edSSimon Baatz 23*96a584dbSSimon Baatz// A too big packet is accepted if the receive queue is empty. It 24*96a584dbSSimon Baatz// does not trigger an immediate ACK. 253eb371edSSimon Baatz +0 < P. 1:20001(20000) ack 1 win 257 26*96a584dbSSimon Baatz +0 %{ assert tcpi_bytes_received == 20000, tcpi_bytes_received; }% 27*96a584dbSSimon Baatz 283eb371edSSimon Baatz// Send a RST immediately so that there is no rcv_wup/rcv_mwnd_seq update yet 293eb371edSSimon Baatz +0 < R. 20001:20001(0) ack 1 win 257 303eb371edSSimon Baatz 31*96a584dbSSimon Baatz// Verify that the RST was accepted. Indirectly this also verifies that no 32*96a584dbSSimon Baatz// immediate ACK was sent for the data packet above. 33*96a584dbSSimon Baatz +0 < . 20001:20001(0) ack 1 win 257 34*96a584dbSSimon Baatz +0 > R 1:1(0) 35