selftests: netfilter: add meta iif/oif match test

simple test case, but would have caught this:

FAIL: iifgroupcount, want "packets 2", got
table inet filter {
        counter iifgroupcount {
                packets 0 bytes 0
        }
}
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

tools/testing/selftests/netfilter/Makefile

@@ -4,7 +4,7 @@
 TEST_PROGS := nft_trans_stress.sh nft_nat.sh bridge_brouter.sh \
 	conntrack_icmp_related.sh nft_flowtable.sh ipvs.sh \
 	nft_concat_range.sh nft_conntrack_helper.sh \
-	nft_queue.sh
+	nft_queue.sh nft_meta.sh
 
 LDLIBS = -lmnl
 TEST_GEN_FILES =  nf-queue

tools/testing/selftests/netfilter/nft_meta.sh

+#!/bin/bash
+
+# check iif/iifname/oifgroup/iiftype match.
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+sfx=$(mktemp -u "XXXXXXXX")
+ns0="ns0-$sfx"
+
+nft --version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not run test without nft tool"
+	exit $ksft_skip
+fi
+
+cleanup()
+{
+	ip netns del "$ns0"
+}
+
+ip netns add "$ns0"
+ip -net "$ns0" link set lo up
+ip -net "$ns0" addr add 127.0.0.1 dev lo
+
+trap cleanup EXIT
+
+ip netns exec "$ns0" nft -f /dev/stdin <<EOF
+table inet filter {
+	counter iifcount {}
+	counter iifnamecount {}
+	counter iifgroupcount {}
+	counter iiftypecount {}
+	counter infproto4count {}
+	counter il4protocounter {}
+	counter imarkcounter {}
+
+	counter oifcount {}
+	counter oifnamecount {}
+	counter oifgroupcount {}
+	counter oiftypecount {}
+	counter onfproto4count {}
+	counter ol4protocounter {}
+	counter oskuidcounter {}
+	counter oskgidcounter {}
+	counter omarkcounter {}
+
+	chain input {
+		type filter hook input priority 0; policy accept;
+
+		meta iif lo counter name "iifcount"
+		meta iifname "lo" counter name "iifnamecount"
+		meta iifgroup "default" counter name "iifgroupcount"
+		meta iiftype "loopback" counter name "iiftypecount"
+		meta nfproto ipv4 counter name "infproto4count"
+		meta l4proto icmp counter name "il4protocounter"
+		meta mark 42 counter name "imarkcounter"
+	}
+
+	chain output {
+		type filter hook output priority 0; policy accept;
+		meta oif lo counter name "oifcount" counter
+		meta oifname "lo" counter name "oifnamecount"
+		meta oifgroup "default" counter name "oifgroupcount"
+		meta oiftype "loopback" counter name "oiftypecount"
+		meta nfproto ipv4 counter name "onfproto4count"
+		meta l4proto icmp counter name "ol4protocounter"
+		meta skuid 0 counter name "oskuidcounter"
+		meta skgid 0 counter name "oskgidcounter"
+		meta mark 42 counter name "omarkcounter"
+	}
+}
+EOF
+
+if [ $? -ne 0 ]; then
+	echo "SKIP: Could not add test ruleset"
+	exit $ksft_skip
+fi
+
+ret=0
+
+check_one_counter()
+{
+	local cname="$1"
+	local want="packets $2"
+	local verbose="$3"
+
+	cnt=$(ip netns exec "$ns0" nft list counter inet filter $cname | grep -q "$want")
+	if [ $? -ne 0 ];then
+		echo "FAIL: $cname, want \"$want\", got"
+		ret=1
+		ip netns exec "$ns0" nft list counter inet filter $counter
+	fi
+}
+
+check_lo_counters()
+{
+	local want="$1"
+	local verbose="$2"
+	local counter
+
+	for counter in iifcount iifnamecount iifgroupcount iiftypecount infproto4count \
+		       oifcount oifnamecount oifgroupcount oiftypecount onfproto4count \
+		       il4protocounter \
+		       ol4protocounter \
+	     ; do
+		check_one_counter "$counter" "$want" "$verbose"
+	done
+}
+
+check_lo_counters "0" false
+ip netns exec "$ns0" ping -q -c 1 127.0.0.1 -m 42 > /dev/null
+
+check_lo_counters "2" true
+
+check_one_counter oskuidcounter "1" true
+check_one_counter oskgidcounter "1" true
+check_one_counter imarkcounter "1" true
+check_one_counter omarkcounter "1" true
+
+if [ $ret -eq 0 ];then
+	echo "OK: nftables meta iif/oif counters at expected values"
+fi
+
+exit $ret