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