git: 685fb4253819 - main - pf: Log the intended action when a NAT rule matches a packet

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=685fb42538199fb03a4cf0f3763c69f146366794

commit 685fb42538199fb03a4cf0f3763c69f146366794
Author:     Franco Fichtner <franco@opnsense.org>
AuthorDate: 2025-02-14 15:14:27 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2025-02-14 15:24:15 +0000

    pf: Log the intended action when a NAT rule matches a packet
    
    When a packet matches a binat/nat/rdr rule, pf logs the match.  The log
    metadata includes the rule's action on the packet, e.g., PF_PASS.  NAT
    rules have their own actions: PF_BINAT, PF_NAT, PF_RDR.
    
    Before commit 948e8413aba0 ("pflog: pass the action to pflog directly"),
    pflog_packet() would obtain the action from the rule definition, whereas
    after that commit the action is passed as a parameter.  When a NAT rule
    matches, we want to log the rule action, but after that commit, PF_PASS
    is hard-coded.  Restore the previous behaviour.
    
    Add a regression test which installs a redirect, logs packets matching
    the redirect rule, and verifies that the corresponding pflog entry
    includes the correct action.
    
    Reviewed by:    kp
    Fixes:          948e8413aba0 ("pflog: pass the action to pflog directly")
    MFC after:      2 weeks
    Sponsored by:   Klara, Inc.
    Sponsored by:   OPNsense
    Differential Revision:  https://reviews.freebsd.org/D48911
---
 sys/netpfil/pf/pf.c           |  2 +-
 tests/sys/netpfil/pf/pflog.sh | 59 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
index c5042a7685c2..236e68457e81 100644
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -5535,7 +5535,7 @@ pf_test_rule(struct pf_krule **rm, struct pf_kstate **sm,
 		KASSERT(nk != NULL, ("%s: null nk", __func__));
 
 		if (nr->log) {
-			PFLOG_PACKET(PF_PASS, PFRES_MATCH, nr, a,
+			PFLOG_PACKET(nr->action, PFRES_MATCH, nr, a,
 			    ruleset, pd, 1);
 		}
 
diff --git a/tests/sys/netpfil/pf/pflog.sh b/tests/sys/netpfil/pf/pflog.sh
index 8288d1d263e8..d885364e0df7 100644
--- a/tests/sys/netpfil/pf/pflog.sh
+++ b/tests/sys/netpfil/pf/pflog.sh
@@ -264,10 +264,69 @@ unspecified_v6_cleanup()
 	pft_cleanup
 }
 
+atf_test_case "rdr_action" "cleanup"
+rdr_head()
+{
+	atf_set descr 'Ensure that NAT rule actions are logged correctly'
+	atf_set require.user root
+}
+
+rdr_action_body()
+{
+	j="pflog:rdr_action"
+	epair_c=$(vnet_mkepair)
+	epair_srv=$(vnet_mkepair)
+
+	vnet_mkjail ${j}srv ${epair_srv}a
+	vnet_mkjail ${j}gw ${epair_srv}b ${epair_c}a
+	vnet_mkjail ${j}c ${epair_c}b
+
+	jexec ${j}srv ifconfig ${epair_srv}a 198.51.100.1/24 up
+	# No default route in srv jail, to ensure we're NAT-ing
+	jexec ${j}gw ifconfig ${epair_srv}b 198.51.100.2/24 up
+	jexec ${j}gw ifconfig ${epair_c}a 192.0.2.1/24 up
+	jexec ${j}gw sysctl net.inet.ip.forwarding=1
+	jexec ${j}c ifconfig ${epair_c}b 192.0.2.2/24 up
+	jexec ${j}c route add default 192.0.2.1
+
+	jexec ${j}gw pfctl -e
+	jexec ${j}gw ifconfig pflog0 up
+	pft_set_rules ${j}gw \
+		"rdr log on ${epair_srv}b proto tcp from 198.51.100.0/24 to any port 1234 -> 192.0.2.2 port 1234" \
+		"block quick inet6" \
+		"pass in log"
+
+	jexec ${j}gw tcpdump -n -e -ttt --immediate-mode -l -U -i pflog0 >> ${PWD}/pflog.txt &
+	sleep 1 # Wait for tcpdump to start
+
+	# send a SYN to catch in the log
+	jexec ${j}srv nc -N -w 0 198.51.100.2 1234
+
+	echo "Log"
+	cat ${PWD}/pflog.txt
+
+	# log line generated for rdr hit (pre-NAT)
+	atf_check -o match:".*.*rule 0/0\(match\): rdr in on ${epair_srv}b: 198.51.100.1.[0-9]* > 198.51.100.2.1234: Flags \[S\].*" \
+	    cat pflog.txt
+
+	# log line generated for pass hit (post-NAT)
+	atf_check -o match:".*.*rule 1/0\(match\): pass in on ${epair_srv}b: 198.51.100.1.[0-9]* > 192.0.2.2.1234: Flags \[S\].*" \
+	    cat pflog.txt
+
+	# only two log lines shall be written
+	atf_check -o match:2 grep -c . pflog.txt
+}
+
+rdr_action_cleanup()
+{
+	pft_cleanup
+}
+
 atf_init_test_cases()
 {
 	atf_add_test_case "malformed"
 	atf_add_test_case "matches"
+	atf_add_test_case "rdr_action"
 	atf_add_test_case "state_max"
 	atf_add_test_case "unspecified_v4"
 	atf_add_test_case "unspecified_v6"