diff options
Diffstat (limited to 'tools/testing')
-rwxr-xr-x | tools/testing/selftests/net/icmp.sh | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/icmp.sh b/tools/testing/selftests/net/icmp.sh new file mode 100755 index 000000000000..e4b04cd1644a --- /dev/null +++ b/tools/testing/selftests/net/icmp.sh @@ -0,0 +1,74 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +# Test for checking ICMP response with dummy address instead of 0.0.0.0. +# Sets up two namespaces like: +# +----------------------+ +--------------------+ +# | ns1 | v4-via-v6 routes: | ns2 | +# | | ' | | +# | +--------+ -> 172.16.1.0/24 -> +--------+ | +# | | veth0 +--------------------------+ veth0 | | +# | +--------+ <- 172.16.0.0/24 <- +--------+ | +# | 172.16.0.1 | | 2001:db8:1::2/64 | +# | 2001:db8:1::2/64 | | | +# +----------------------+ +--------------------+ +# +# And then tries to ping 172.16.1.1 from ns1. This results in a "net +# unreachable" message being sent from ns2, but there is no IPv4 address set in +# that address space, so the kernel should substitute the dummy address +# 192.0.0.8 defined in RFC7600. + +NS1=ns1 +NS2=ns2 +H1_IP=172.16.0.1/32 +H1_IP6=2001:db8:1::1 +RT1=172.16.1.0/24 +PINGADDR=172.16.1.1 +RT2=172.16.0.0/24 +H2_IP6=2001:db8:1::2 + +TMPFILE=$(mktemp) + +cleanup() +{ + rm -f "$TMPFILE" + ip netns del $NS1 + ip netns del $NS2 +} + +trap cleanup EXIT + +# Namespaces +ip netns add $NS1 +ip netns add $NS2 + +# Connectivity +ip -netns $NS1 link add veth0 type veth peer name veth0 netns $NS2 +ip -netns $NS1 link set dev veth0 up +ip -netns $NS2 link set dev veth0 up +ip -netns $NS1 addr add $H1_IP dev veth0 +ip -netns $NS1 addr add $H1_IP6/64 dev veth0 nodad +ip -netns $NS2 addr add $H2_IP6/64 dev veth0 nodad +ip -netns $NS1 route add $RT1 via inet6 $H2_IP6 +ip -netns $NS2 route add $RT2 via inet6 $H1_IP6 + +# Make sure ns2 will respond with ICMP unreachable +ip netns exec $NS2 sysctl -qw net.ipv4.icmp_ratelimit=0 net.ipv4.ip_forward=1 + +# Run the test - a ping runs in the background, and we capture ICMP responses +# with tcpdump; -c 1 means it should exit on the first ping, but add a timeout +# in case something goes wrong +ip netns exec $NS1 ping -w 3 -i 0.5 $PINGADDR >/dev/null & +ip netns exec $NS1 timeout 10 tcpdump -tpni veth0 -c 1 'icmp and icmp[icmptype] != icmp-echo' > $TMPFILE 2>/dev/null + +# Parse response and check for dummy address +# tcpdump output looks like: +# IP 192.0.0.8 > 172.16.0.1: ICMP net 172.16.1.1 unreachable, length 92 +RESP_IP=$(awk '{print $2}' < $TMPFILE) +if [[ "$RESP_IP" != "192.0.0.8" ]]; then + echo "FAIL - got ICMP response from $RESP_IP, should be 192.0.0.8" + exit 1 +else + echo "OK" + exit 0 +fi |