pf: fix 'no rdr'

Ensure we always have a non-NULL rule pointer (ctx.rm).
It might have gotten set to NULL by pf_get_translation().

While here also restore the previous rdr behaviour be re-adding the incorrectly
removed 'break' in pf_match_translation_rule.

Approved by:	re (cperciva)
PR:		290177
MFC after:	3 days
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D53191

(cherry picked from commit cb36bfe)
(cherry picked from commit 536b075)

Author: kprovost

sys/netpfil/pf/pf.c

@@ -5939,6 +5939,7 @@ pf_test_rule(struct pf_krule **rm, struct pf_kstate **sm,
 		ctx.nat_pool = &(ctx.nr->rdr);
 	}
 
+	*ctx.rm = &V_pf_default_rule;
 	if (ctx.nr && ctx.nr->natpass) {
 		r = ctx.nr;
 		ruleset = *ctx.rsm;

sys/netpfil/pf/pf_lb.c

@@ -216,6 +216,7 @@ pf_match_translation_rule(int rs_num, struct pf_test_ctx *ctx, struct pf_krulese
 				 */
 				ctx->arsm = ctx->aruleset;
 			}
+			break;
 		} else {
 			ctx->a = r;			/* remember anchor */
 			ctx->aruleset = ruleset;	/* and its ruleset */

tests/sys/netpfil/pf/rdr.sh

@@ -338,11 +338,62 @@ natpass_cleanup()
 	pft_cleanup
 }
 
+atf_test_case "pr290177" "cleanup"
+pr290177_head()
+{
+	atf_set descr 'Test PR290177'
+	atf_set require.user root
+}
+
+pr290177_body()
+{
+	pft_init
+
+	epair=$(vnet_mkepair)
+
+	ifconfig ${epair}a 192.0.2.2/24 up
+	ifconfig ${epair}a inet alias 192.0.2.3/24 up
+
+	vnet_mkjail alcatraz ${epair}b
+	jexec alcatraz ifconfig ${epair}b 192.0.2.1/24 up
+	jexec alcatraz ifconfig lo0 127.0.0.1/8 up
+
+	# Sanity check
+	atf_check -s exit:0 -o ignore \
+	    ping -c 1 192.0.2.1
+
+	jexec alcatraz pfctl -e
+	pft_set_rules alcatraz \
+	    "table <white> { 192.0.2.2 }" \
+	    "no rdr inet proto tcp from <white> to any port 25" \
+	    "rdr pass inet proto tcp from any to any port 25 -> 127.0.0.1 port 2500"
+
+	echo foo | jexec alcatraz nc -N -l 2500 &
+	sleep 1
+
+	reply=$(nc -w 3 -s 192.0.2.2 192.0.2.1 25)
+	if [ "${reply}" == "foo" ]
+	then
+		atf_fail "no rdr rule failed"
+	fi
+	reply=$(nc -w 3 -s 192.0.2.3 192.0.2.1 25)
+	if [ "${reply}" != "foo" ]
+	then
+		atf_fail "rdr rule failed"
+	fi
+}
+
+pr290177_cleanup()
+{
+	pft_cleanup
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case "natpass"
 	atf_add_test_case "tcp_v6_compat"
 	atf_add_test_case "tcp_v6_pass"
 	atf_add_test_case "srcport_compat"
 	atf_add_test_case "srcport_pass"
+	atf_add_test_case "pr290177"
 }