1*88395c07SSoham Chakradeo// SPDX-License-Identifier: GPL-2.0 2*88395c07SSoham Chakradeo// Test shifting of newly-SACKed ranges onto the previous already-SACKed skb. 3*88395c07SSoham Chakradeo// This variant tests the case where we mark packets 0-4 lost, then 4*88395c07SSoham Chakradeo// get a SACK for 3, and then a SACK for 4. 5*88395c07SSoham Chakradeo 6*88395c07SSoham Chakradeo`./defaults.sh` 7*88395c07SSoham Chakradeo 8*88395c07SSoham Chakradeo// Establish a connection and send 10 MSS. 9*88395c07SSoham Chakradeo 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 10*88395c07SSoham Chakradeo +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 11*88395c07SSoham Chakradeo +0 bind(3, ..., ...) = 0 12*88395c07SSoham Chakradeo +0 listen(3, 1) = 0 13*88395c07SSoham Chakradeo 14*88395c07SSoham Chakradeo +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> 15*88395c07SSoham Chakradeo +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 16*88395c07SSoham Chakradeo +.1 < . 1:1(0) ack 1 win 1024 17*88395c07SSoham Chakradeo +0 accept(3, ..., ...) = 4 18*88395c07SSoham Chakradeo 19*88395c07SSoham Chakradeo +0 write(4, ..., 10000) = 10000 20*88395c07SSoham Chakradeo +0 > P. 1:10001(10000) ack 1 21*88395c07SSoham Chakradeo 22*88395c07SSoham Chakradeo// SACK for 7001:8001. Using RACK we delay the fast retransmit. 23*88395c07SSoham Chakradeo +.1 < . 1:1(0) ack 1 win 257 <sack 7001:8001,nop,nop> 24*88395c07SSoham Chakradeo// RACK reordering timer 25*88395c07SSoham Chakradeo+.027 > . 1:1001(1000) ack 1 26*88395c07SSoham Chakradeo +0 %{ 27*88395c07SSoham Chakradeoassert tcpi_ca_state == TCP_CA_Recovery, tcpi_ca_state 28*88395c07SSoham Chakradeoassert tcpi_lost == 7, tcpi_lost # RACK thinks 1:7001 are lost 29*88395c07SSoham Chakradeoassert tcpi_reordering == 3, tcpi_reordering 30*88395c07SSoham Chakradeo}% 31*88395c07SSoham Chakradeo 32*88395c07SSoham Chakradeo// SACK for 3001:4001. 33*88395c07SSoham Chakradeo+.002 < . 1:1(0) ack 1 win 257 <sack 3001:4001 7001:8001,nop,nop> 34*88395c07SSoham Chakradeo +0 > . 1001:2001(1000) ack 1 35*88395c07SSoham Chakradeo +0 %{ 36*88395c07SSoham Chakradeoassert tcpi_lost == 6, tcpi_lost # since 3001:4001 is no longer lost 37*88395c07SSoham Chakradeoassert tcpi_reordering == 5, tcpi_reordering # 7001:8001 -> 3001:4001 38*88395c07SSoham Chakradeo}% 39*88395c07SSoham Chakradeo 40*88395c07SSoham Chakradeo// SACK for 4001:5001. 41*88395c07SSoham Chakradeo// This SACK for an adjacent range causes the sender to 42*88395c07SSoham Chakradeo// shift the newly-SACKed range onto the previous skb. 43*88395c07SSoham Chakradeo// It uses the RFC3517 algorithm to mark 1:3001 lost 44*88395c07SSoham Chakradeo// because >=3 higher-sequence packets are SACKed. 45*88395c07SSoham Chakradeo+.002 < . 1:1(0) ack 1 win 257 <sack 3001:5001 7001:8001,nop,nop> 46*88395c07SSoham Chakradeo +0 > . 2001:3001(1000) ack 1 47*88395c07SSoham Chakradeo +0 %{ 48*88395c07SSoham Chakradeoassert tcpi_lost == 5,tcpi_lost # SACK/RFC3517 thinks 1:3001 are lost 49*88395c07SSoham Chakradeo}% 50*88395c07SSoham Chakradeo 51*88395c07SSoham Chakradeo// SACK for 8001:9001. 52*88395c07SSoham Chakradeo+.002 < . 1:1(0) ack 1 win 257 <sack 3001:5001 7001:9001,nop,nop> 53*88395c07SSoham Chakradeo 54*88395c07SSoham Chakradeo// SACK for 9001:10001. 55*88395c07SSoham Chakradeo+.002 < . 1:1(0) ack 1 win 257 <sack 3001:5001 7001:10001,nop,nop> 56*88395c07SSoham Chakradeo +0 > . 5001:6001(1000) ack 1 57*88395c07SSoham Chakradeo 58*88395c07SSoham Chakradeo// To simplify clean-up, say we get an ACK for all data. 59*88395c07SSoham Chakradeo +.1 < . 1:1(0) ack 10001 win 257 60*88395c07SSoham Chakradeo +0 %{ 61*88395c07SSoham Chakradeoassert tcpi_ca_state == TCP_CA_Open, tcpi_ca_state 62*88395c07SSoham Chakradeoassert tcpi_unacked == 0, tcpi_unacked 63*88395c07SSoham Chakradeoassert tcpi_sacked == 0, tcpi_sacked 64*88395c07SSoham Chakradeoassert tcpi_lost == 0, tcpi_lost 65*88395c07SSoham Chakradeoassert tcpi_retrans == 0, tcpi_retrans 66*88395c07SSoham Chakradeo}% 67