tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3--mss=1000
4
5`./defaults.sh`
6
7 0 `nstat -n`
8
9// Establish a connection.
10 +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
11 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
12 +0 setsockopt(3, SOL_SOCKET, SO_RCVBUF, [10000], 4) = 0
13 +0 bind(3, ..., ...) = 0
14 +0 listen(3, 1) = 0
15
16 +0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7>
17 +0 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 0>
18 +.1 < . 1:1(0) ack 1 win 257
19
20 +0 accept(3, ..., ...) = 4
21
22 +0 < P. 1:4001(4000) ack 1 win 257
23 +0 > . 1:1(0) ack 4001 win 5000
24
25// packet in sequence : SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE / LINUX_MIB_BEYOND_WINDOW
26 +0 < P. 4001:54001(50000) ack 1 win 257
27 +0 > . 1:1(0) ack 4001 win 5000
28
29// ooo packet. : SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE / LINUX_MIB_BEYOND_WINDOW
30 +1 < P. 5001:55001(50000) ack 1 win 257
31 +0 > . 1:1(0) ack 4001 win 5000
32
33// SKB_DROP_REASON_TCP_INVALID_SEQUENCE / LINUX_MIB_BEYOND_WINDOW
34 +0 < P. 70001:80001(10000) ack 1 win 257
35 +0 > . 1:1(0) ack 4001 win 5000
36
37 +0 read(4, ..., 100000) = 4000
38
39// If queue is empty, accept a packet even if its end_seq is above wup + rcv_wnd
40 +0 < P. 4001:54001(50000) ack 1 win 257
41 +0 > . 1:1(0) ack 54001 win 0
42
43// Check LINUX_MIB_BEYOND_WINDOW has been incremented 3 times.
44+0 `nstat | grep TcpExtBeyondWindow | grep -q " 3 "`