| #!/bin/bash |
| # SPDX-License-Identifier: GPL-2.0 |
| # |
| # Ensures broadcast route MTU is respected |
| |
| CLIENT_NS=$(mktemp -u client-XXXXXXXX) |
| CLIENT_IP4="192.168.0.1/24" |
| CLIENT_BROADCAST_ADDRESS="192.168.0.255" |
| |
| SERVER_NS=$(mktemp -u server-XXXXXXXX) |
| SERVER_IP4="192.168.0.2/24" |
| |
| setup() { |
| ip netns add "${CLIENT_NS}" |
| ip netns add "${SERVER_NS}" |
| |
| ip -net "${SERVER_NS}" link add link1 type veth peer name link0 netns "${CLIENT_NS}" |
| |
| ip -net "${CLIENT_NS}" link set link0 up |
| ip -net "${CLIENT_NS}" link set link0 mtu 9000 |
| ip -net "${CLIENT_NS}" addr add "${CLIENT_IP4}" dev link0 |
| |
| ip -net "${SERVER_NS}" link set link1 up |
| ip -net "${SERVER_NS}" link set link1 mtu 1500 |
| ip -net "${SERVER_NS}" addr add "${SERVER_IP4}" dev link1 |
| |
| read -r -a CLIENT_BROADCAST_ENTRY <<< "$(ip -net "${CLIENT_NS}" route show table local type broadcast)" |
| ip -net "${CLIENT_NS}" route del "${CLIENT_BROADCAST_ENTRY[@]}" |
| ip -net "${CLIENT_NS}" route add "${CLIENT_BROADCAST_ENTRY[@]}" mtu 1500 |
| |
| ip net exec "${SERVER_NS}" sysctl -wq net.ipv4.icmp_echo_ignore_broadcasts=0 |
| } |
| |
| cleanup() { |
| ip -net "${SERVER_NS}" link del link1 |
| ip netns del "${CLIENT_NS}" |
| ip netns del "${SERVER_NS}" |
| } |
| |
| trap cleanup EXIT |
| |
| setup && |
| echo "Testing for broadcast route MTU" && |
| ip net exec "${CLIENT_NS}" ping -f -M want -q -c 1 -s 8000 -w 1 -b "${CLIENT_BROADCAST_ADDRESS}" > /dev/null 2>&1 |
| |
| exit $? |
| |
