Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3#
4# Ensures broadcast route MTU is respected
5
6CLIENT_NS=$(mktemp -u client-XXXXXXXX)
7CLIENT_IP4="192.168.0.1/24"
8CLIENT_BROADCAST_ADDRESS="192.168.0.255"
9
10SERVER_NS=$(mktemp -u server-XXXXXXXX)
11SERVER_IP4="192.168.0.2/24"
12
13setup() {
14 ip netns add "${CLIENT_NS}"
15 ip netns add "${SERVER_NS}"
16
17 ip -net "${SERVER_NS}" link add link1 type veth peer name link0 netns "${CLIENT_NS}"
18
19 ip -net "${CLIENT_NS}" link set link0 up
20 ip -net "${CLIENT_NS}" link set link0 mtu 9000
21 ip -net "${CLIENT_NS}" addr add "${CLIENT_IP4}" dev link0
22
23 ip -net "${SERVER_NS}" link set link1 up
24 ip -net "${SERVER_NS}" link set link1 mtu 1500
25 ip -net "${SERVER_NS}" addr add "${SERVER_IP4}" dev link1
26
27 read -r -a CLIENT_BROADCAST_ENTRY <<< "$(ip -net "${CLIENT_NS}" route show table local type broadcast)"
28 ip -net "${CLIENT_NS}" route del "${CLIENT_BROADCAST_ENTRY[@]}"
29 ip -net "${CLIENT_NS}" route add "${CLIENT_BROADCAST_ENTRY[@]}" mtu 1500
30
31 ip net exec "${SERVER_NS}" sysctl -wq net.ipv4.icmp_echo_ignore_broadcasts=0
32}
33
34cleanup() {
35 ip -net "${SERVER_NS}" link del link1
36 ip netns del "${CLIENT_NS}"
37 ip netns del "${SERVER_NS}"
38}
39
40trap cleanup EXIT
41
42setup &&
43 echo "Testing for broadcast route MTU" &&
44 ip net exec "${CLIENT_NS}" ping -f -M want -q -c 1 -s 8000 -w 1 -b "${CLIENT_BROADCAST_ADDRESS}" > /dev/null 2>&1
45
46exit $?
47