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// Test TCP_INQ and TCP_CM_INQ on the server side.
3
4--mss=1000
5
6`./defaults.sh
7`
8
9// Initialize connection
10 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
11 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
12 +0 bind(3, ..., ...) = 0
13 +0 listen(3, 1) = 0
14
15 +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 10>
16 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
17 +.01 < . 1:1(0) ack 1 win 514
18
19// Accept the connection and enable TCP_INQ.
20 +0 accept(3, ..., ...) = 4
21 +0 setsockopt(4, SOL_TCP, TCP_INQ, [1], 4) = 0
22
23// Now we have 10K of data ready on the socket.
24 +0 < . 1:10001(10000) ack 1 win 514
25 +0 > . 1:1(0) ack 10001
26
27// We read 2K and we should have 8K ready to read.
28 +0 recvmsg(4, {msg_name(...)=...,
29 msg_iov(1)=[{..., 2000}],
30 msg_flags=0,
31 msg_control=[{cmsg_level=SOL_TCP,
32 cmsg_type=TCP_CM_INQ,
33 cmsg_data=8000}]}, 0) = 2000
34// We read 8K and we should have no further data ready to read.
35 +0 recvmsg(4, {msg_name(...)=...,
36 msg_iov(1)=[{..., 8000}],
37 msg_flags=0,
38 msg_control=[{cmsg_level=SOL_TCP,
39 cmsg_type=TCP_CM_INQ,
40 cmsg_data=0}]}, 0) = 8000
41// Client sends more data and closes the connections.
42 +0 < F. 10001:20001(10000) ack 1 win 514
43 +0 > . 1:1(0) ack 20002
44
45// We read 10K and we should have one "fake" byte because the connection is
46// closed.
47 +0 recvmsg(4, {msg_name(...)=...,
48 msg_iov(1)=[{..., 10000}],
49 msg_flags=0,
50 msg_control=[{cmsg_level=SOL_TCP,
51 cmsg_type=TCP_CM_INQ,
52 cmsg_data=1}]}, 0) = 10000
53// Now, receive error.
54 +0 read(3, ..., 2000) = -1 ENOTCONN (Transport endpoint is not connected)