| #!/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 $? | |