pf tests: Test the match keyword

The new match keyword can currently only assign queues, so we can only
test it with ALTQ.
Set up a basic scenario where we use 'match' to assign ICMP traffic to a
slow queue, and confirm that it's really getting slowed down.

MFC after:	2 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D31116

tests/sys/netpfil/pf/altq.sh

@@ -42,8 +42,53 @@ hfsc_cleanup()
 	altq_cleanup
 }
 
+atf_test_case "match" "cleanup"
+match_head()
+{
+	atf_set descr 'Basic match keyword test'
+	atf_set require.user root
+}
+
+match_body()
+{
+	altq_init
+	is_altq_supported hfsc
+
+	epair=$(vnet_mkepair)
+	vnet_mkjail altq_match ${epair}b
+
+	ifconfig ${epair}a 192.0.2.1/24 up
+	jexec altq_match ifconfig ${epair}b 192.0.2.2/24 up
+
+	# Sanity check
+	atf_check -s exit:0 -o ignore ping -i .1 -c 3 -s 1200 192.0.2.2
+
+	jexec altq_match pfctl -e
+	pft_set_rules altq_match \
+	    "altq on ${epair}b bandwidth 100000000b hfsc queue { default, slow }" \
+	    "queue default hfsc(default linkshare 80000000b)" \
+	    "queue slow hfsc(linkshare 80b upperlimit 80b)" \
+	    "match proto icmp queue slow" \
+	    "pass"
+
+	# single ping succeeds just fine
+	atf_check -s exit:0 -o ignore ping -c 1 192.0.2.2
+
+	# "Saturate the link"
+	ping -i .1 -c 5 -s 1200 192.0.2.2
+
+	# We should now be hitting the limits and get this packet dropped.
+	atf_check -s exit:2 -o ignore ping -c 1 -s 1200 192.0.2.2
+}
+
+match_cleanup()
+{
+	altq_cleanup
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case "hfsc"
+	atf_add_test_case "match"
 }