1// SPDX-License-Identifier: GPL-2.0 2// Test shifting of newly-SACKed ranges onto the previous already-SACKed skb. 3// This variant tests the case where we mark packets 0-4 lost, then 4// get a SACK for 5, and then a SACK for 6. 5 6`./defaults.sh` 7 8// Establish a connection and send 10 MSS. 9 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 10 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 11 +0 bind(3, ..., ...) = 0 12 +0 listen(3, 1) = 0 13 14 +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> 15 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 16 +.1 < . 1:1(0) ack 1 win 1024 17 +0 accept(3, ..., ...) = 4 18 19 +0 write(4, ..., 10000) = 10000 20 +0 > P. 1:10001(10000) ack 1 21 22// SACK for 7001:8001. Using RACK we delay a fast retransmit. 23 +.1 < . 1:1(0) ack 1 win 257 <sack 7001:8001,nop,nop> 24+.027 > . 1:1001(1000) ack 1 25 +0 %{ 26assert tcpi_ca_state == TCP_CA_Recovery, tcpi_ca_state 27assert tcpi_lost == 7,tcpi_lost # RACK thinks 1:7001 are lost 28assert tcpi_reordering == 3, tcpi_reordering 29}% 30 31// SACK for 5001:6001. 32 +0 < . 1:1(0) ack 1 win 257 <sack 5001:6001 7001:8001,nop,nop> 33 +0 > . 1001:2001(1000) ack 1 34 +0 %{ 35assert tcpi_lost == 6, tcpi_lost 36assert tcpi_reordering == 3, tcpi_reordering # 7001:8001 -> 5001:6001 is 3 37}% 38 39// SACK for 6001:7001. 40// This SACK for an adjacent range causes the sender to 41// shift the newly-SACKed range onto the previous skb. 42 +0 < . 1:1(0) ack 1 win 257 <sack 5001:8001,nop,nop> 43 +0 > . 2001:3001(1000) ack 1 44 +0 %{ assert tcpi_lost == 5, tcpi_lost }% 45 46// SACK for 8001:9001. 47 +0 < . 1:1(0) ack 1 win 257 <sack 5001:9001,nop,nop> 48 +0 > . 3001:4001(1000) ack 1 49 50// SACK for 9001:10001. 51 +0 < . 1:1(0) ack 1 win 257 <sack 5001:10001,nop,nop> 52 +0 > . 4001:5001(1000) ack 1 53 54// To simplify clean-up, say we get an ACK for all data. 55 +.1 < . 1:1(0) ack 10001 win 257 56 +0 %{ 57assert tcpi_ca_state == TCP_CA_Open, tcpi_ca_state 58assert tcpi_unacked == 0, tcpi_unacked 59assert tcpi_sacked == 0, tcpi_sacked 60assert tcpi_lost == 0, tcpi_lost 61assert tcpi_retrans == 0, tcpi_retrans 62}% 63