[Devel] [PATCH vz10 1/4] selftests: netfilter: do not inherit forwarding and redirects

[Eva Kurchatova <eva.kurchatova@virtuozzo.com>]

A new namespace takes ip_forward and send_redirects from the host, so
two tests depend on how the machine outside them is configured.

On a host that forwards, which any hypervisor does, nft_fib's ns1 and
ns2 send the test packets back at the router until their TTL runs out,
and the fib counters end at 31 or 62 packets instead of 1:

  FAIL: fibif4 not empty
    elements = { "veth1" . 10.0.1.99 . "veth0" counter packets 62 ...

Only nsrouter is meant to forward, so turn forwarding off in the
endpoints.  conntrack_icmp_related needs the opposite: images routinely
turn send_redirects off, and the router then never sends the redirect
the test waits for:

  ERROR: counter redir4 in nsclient1 has unexpected value

Set both where the test needs them rather than relying on the host.

https://virtuozzo.atlassian.net/browse/VSTOR-139651
Feature: fix selftests
Signed-off-by: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
---
 .../selftests/net/netfilter/conntrack_icmp_related.sh     | 6 ++++++
 tools/testing/selftests/net/netfilter/nft_fib.sh          | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/tools/testing/selftests/net/netfilter/conntrack_icmp_related.sh b/tools/testing/selftests/net/netfilter/conntrack_icmp_related.sh
index c63d840ead61..44a98c53d085 100755
--- a/tools/testing/selftests/net/netfilter/conntrack_icmp_related.sh
+++ b/tools/testing/selftests/net/netfilter/conntrack_icmp_related.sh
@@ -253,6 +253,12 @@ else
 fi
 
 # add 'bad' route,  expect icmp REDIRECT to be generated
+# A new namespace inherits send_redirects from the host, where it is
+# often turned off; without it the router never sends the redirect this
+# part of the test waits for.
+ip netns exec "$nsrouter1" sysctl -q net.ipv4.conf.all.send_redirects=1
+ip netns exec "$nsrouter1" sysctl -q net.ipv4.conf.default.send_redirects=1
+
 ip netns exec "${nsclient1}" ip route add 192.168.1.42 via 192.168.1.1
 ip netns exec "${nsclient1}" ip route add dead:1::42 via dead:1::1
 
diff --git a/tools/testing/selftests/net/netfilter/nft_fib.sh b/tools/testing/selftests/net/netfilter/nft_fib.sh
index 9929a9ffef65..c818b544e57b 100755
--- a/tools/testing/selftests/net/netfilter/nft_fib.sh
+++ b/tools/testing/selftests/net/netfilter/nft_fib.sh
@@ -29,6 +29,14 @@ setup_ns nsrouter ns1 ns2
 
 trap cleanup EXIT
 
+# A new namespace inherits ip_forward from the host, and on a host that
+# forwards, ns1 and ns2 bounce the test packets back at the router until
+# their TTL runs out. Only nsrouter is meant to forward here.
+for ns in "$ns1" "$ns2"; do
+	ip netns exec "$ns" sysctl -q net.ipv4.ip_forward=0
+	ip netns exec "$ns" sysctl -q net.ipv6.conf.all.forwarding=0
+done
+
 if dmesg | grep -q ' nft_rpfilter: ';then
 	dmesg -c | grep ' nft_rpfilter: '
 	echo "WARN: a previous test run has failed" 1>&2
-- 
2.55.0