git: 820804014074 - stable/15 - pf: first-match-wins for nat rules, even in anchors

The branch stable/15 has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=820804014074cdc4f56dca7a3966019b8aa172ae

commit 820804014074cdc4f56dca7a3966019b8aa172ae
Author:     Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2026-10-13 12:40:58 +0000
Commit:     Kristof Provost <kp@FreeBSD.org>
CommitDate: 2026-10-20 13:53:41 +0000

    pf: first-match-wins for nat rules, even in anchors
    
    Ensure we stop evaluating nat rules if we find a match in a nat-anchor.
    
    PR:             299320
    MFC after:      1 week
    Sponsored by:   Rubicon Communications, LLC ("Netgate")
    
    (cherry picked from commit b5219c068fbc133dde91d5cf48423e34ce27bd4f)
---
 sys/netpfil/pf/pf_lb.c      |  4 ++
 tests/sys/netpfil/pf/nat.sh | 91 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 95 insertions(+)

diff --git a/sys/netpfil/pf/pf_lb.c b/sys/netpfil/pf/pf_lb.c
index cb99038a07fa..eecb14149dfd 100644
--- a/sys/netpfil/pf/pf_lb.c
+++ b/sys/netpfil/pf/pf_lb.c
@@ -224,6 +224,10 @@ pf_match_translation_rule(int rs_num, struct pf_test_ctx *ctx, struct pf_krulese
 			    r) != PF_TEST_OK) {
 				break;
 			}
+			/* If we found a match in the anchor we're done. */
+			if (ctx->tr != NULL) {
+				break;
+			}
 		}
 		r = TAILQ_NEXT(r, entries);
 	}
diff --git a/tests/sys/netpfil/pf/nat.sh b/tests/sys/netpfil/pf/nat.sh
index 1355da83d2f3..47292b1c7642 100644
--- a/tests/sys/netpfil/pf/nat.sh
+++ b/tests/sys/netpfil/pf/nat.sh
@@ -916,6 +916,95 @@ empty_pool_cleanup()
 	pft_cleanup
 }
 
+atf_test_case "first_match" "cleanup"
+first_match_head()
+{
+	atf_set descr 'Test that NAT rules are first match'
+	atf_set require.user root
+}
+
+first_match_body()
+{
+	pft_init
+
+	epair_nat=$(vnet_mkepair)
+	epair_echo=$(vnet_mkepair)
+
+	vnet_mkjail nat ${epair_nat}b ${epair_echo}a
+	vnet_mkjail echo ${epair_echo}b
+
+	ifconfig ${epair_nat}a 192.0.2.2/24 up
+	route add -net 198.51.100.0/24 192.0.2.1
+
+	jexec nat ifconfig ${epair_nat}b 192.0.2.1/24 up
+	jexec nat ifconfig ${epair_echo}a 198.51.100.1/24 up
+	jexec nat sysctl net.inet.ip.forwarding=1
+
+	jexec echo ifconfig ${epair_echo}b 198.51.100.2/24 up
+
+	# Enable pf!
+	jexec nat pfctl -e
+	pft_set_rules nat \
+		"table <foo> { 192.0.2.0/24 }" \
+		"nat on ${epair_echo}a inet from <foo> to any -> 198.51.100.1" \
+		"nat on ${epair_echo}a inet from 192.0.2.0/24 to any -> 198.51.100.3"
+
+	atf_check -s exit:0 -o ignore ping -c 3 198.51.100.2
+	atf_check -s exit:0 -e ignore \
+	    -o match:"all icmp 198.51.100.1:.*(192.0.2.2:.*) -> 198.51.100.2:8.*" \
+		jexec nat pfctl -ss
+}
+
+first_match_cleanup()
+{
+	pft_cleanup
+}
+
+atf_test_case "first_match_anchor" "cleanup"
+first_match_anchor_head()
+{
+	atf_set descr 'Test that NAT matches within an anchor are final (PR 299320)'
+	atf_set require.user root
+}
+
+first_match_anchor_body()
+{
+	pft_init
+
+	epair_nat=$(vnet_mkepair)
+	epair_echo=$(vnet_mkepair)
+
+	vnet_mkjail nat ${epair_nat}b ${epair_echo}a
+	vnet_mkjail echo ${epair_echo}b
+
+	ifconfig ${epair_nat}a 192.0.2.2/24 up
+	route add -net 198.51.100.0/24 192.0.2.1
+
+	jexec nat ifconfig ${epair_nat}b 192.0.2.1/24 up
+	jexec nat ifconfig ${epair_echo}a 198.51.100.1/24 up
+	jexec nat sysctl net.inet.ip.forwarding=1
+
+	jexec echo ifconfig ${epair_echo}b 198.51.100.2/24 up
+
+	# Enable pf!
+	jexec nat pfctl -e
+	pft_set_rules nat \
+		"nat-anchor \"foo\"" \
+		"nat on ${epair_echo}a inet from 192.0.2.0/24 to any -> 198.51.100.3"
+
+	echo "nat on ${epair_echo}a inet from 192.0.2.0/24 to any -> 198.51.100.1" | jexec nat pfctl -g -f - -a "foo"
+
+	atf_check -s exit:0 -o ignore ping -c 3 198.51.100.2
+	atf_check -s exit:0 -e ignore \
+	    -o match:"all icmp 198.51.100.1:.*(192.0.2.2:.*) -> 198.51.100.2:8.*" \
+		jexec nat pfctl -ss
+}
+
+first_match_anchor_cleanup()
+{
+	pft_cleanup
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case "exhaust"
@@ -937,4 +1026,6 @@ atf_init_test_cases()
 	atf_add_test_case "binat_compat"
 	atf_add_test_case "binat_match"
 	atf_add_test_case "empty_pool"
+	atf_add_test_case "first_match"
+	atf_add_test_case "first_match_anchor"
 }