selftests: netfilter: run conntrack_dump_flush in netns

This test will fail if the initial namespace has conntrack
active due to unexpected number of flows returned on dump:

  conntrack_dump_flush.c:451:test_flush_by_zone:Expected ret (7) == 2 (2)
  test_flush_by_zone: Test failed
  FAIL  conntrack_dump_flush.test_flush_by_zone
  not ok 2 conntrack_dump_flush.test_flush_by_zone

Add a wrapper that unshares this program to avoid this problem.

Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://patch.msgid.link/20241104142529.2352-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Florian Westphal

tools/testing/selftests/net/netfilter/Makefile

@@ -8,6 +8,7 @@ MNL_LDLIBS := $(shell $(HOSTPKG_CONFIG) --libs libmnl 2>/dev/null || echo -lmnl)
 
 TEST_PROGS := br_netfilter.sh bridge_brouter.sh
 TEST_PROGS += br_netfilter_queue.sh
+TEST_PROGS += conntrack_dump_flush.sh
 TEST_PROGS += conntrack_icmp_related.sh
 TEST_PROGS += conntrack_ipip_mtu.sh
 TEST_PROGS += conntrack_tcp_unreplied.sh
@@ -36,10 +37,9 @@ TEST_PROGS += xt_string.sh
 
 TEST_PROGS_EXTENDED = nft_concat_range_perf.sh
 
-TEST_GEN_PROGS = conntrack_dump_flush
-
 TEST_GEN_FILES = audit_logread
 TEST_GEN_FILES += connect_close nf_queue
+TEST_GEN_FILES += conntrack_dump_flush
 TEST_GEN_FILES += conntrack_reverse_clash
 TEST_GEN_FILES += sctp_collision
 

tools/testing/selftests/net/netfilter/conntrack_dump_flush.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+exec unshare -n ./conntrack_dump_flush