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