wifi: mac80211: add kunit tests for public action handling

Check the logic in ieee80211_drop_unencrypted_mgmt()
according to a list of test cases derived from the
spec.
Reviewed-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://msgid.link/20231220151952.415232-4-benjamin@sipsolutions.netSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/ieee80211_i.h

@@ -2608,4 +2608,14 @@ void ieee80211_check_wbrf_support(struct ieee80211_local *local);
 void ieee80211_add_wbrf(struct ieee80211_local *local, struct cfg80211_chan_def *chandef);
 void ieee80211_remove_wbrf(struct ieee80211_local *local, struct cfg80211_chan_def *chandef);
 
+#if IS_ENABLED(CONFIG_MAC80211_KUNIT_TEST)
+#define EXPORT_SYMBOL_IF_MAC80211_KUNIT(sym) EXPORT_SYMBOL_IF_KUNIT(sym)
+#define VISIBLE_IF_MAC80211_KUNIT
+ieee80211_rx_result
+ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx);
+#else
+#define EXPORT_SYMBOL_IF_MAC80211_KUNIT(sym)
+#define VISIBLE_IF_MAC80211_KUNIT static
+#endif
+
 #endif /* IEEE80211_I_H */

net/mac80211/rx.c

@@ -19,6 +19,7 @@
 #include <linux/export.h>
 #include <linux/kcov.h>
 #include <linux/bitops.h>
+#include <kunit/visibility.h>
 #include <net/mac80211.h>
 #include <net/ieee80211_radiotap.h>
 #include <asm/unaligned.h>
@@ -2414,7 +2415,7 @@ static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
 	return 0;
 }
 
-static ieee80211_rx_result
+VISIBLE_IF_MAC80211_KUNIT ieee80211_rx_result
 ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
 {
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
@@ -2493,6 +2494,7 @@ ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
 
 	return RX_CONTINUE;
 }
+EXPORT_SYMBOL_IF_MAC80211_KUNIT(ieee80211_drop_unencrypted_mgmt);
 
 static ieee80211_rx_result
 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)

net/mac80211/tests/Makefile

-mac80211-tests-y += module.o elems.o
+mac80211-tests-y += module.o elems.o mfp.o
 
 obj-$(CONFIG_MAC80211_KUNIT_TEST) += mac80211-tests.o

net/mac80211/tests/mfp.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KUnit tests for management frame acceptance
+ *
+ * Copyright (C) 2023 Intel Corporation
+ */
+#include <kunit/test.h>
+#include <kunit/skbuff.h>
+#include "../ieee80211_i.h"
+#include "../sta_info.h"
+
+MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING);
+
+static const struct mfp_test_case {
+	const char *desc;
+	bool sta, mfp, decrypted, unicast, protected_dual;
+	ieee80211_rx_result result;
+} accept_public_action_cases[] = {
+	/* regular public action */
+	{
+		.desc = "public action: accept unicast from unknown peer",
+		.unicast = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: accept multicast from unknown peer",
+		.unicast = false,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: accept unicast without MFP",
+		.unicast = true,
+		.sta = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: accept multicast without MFP",
+		.unicast = false,
+		.sta = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "public action: drop unicast with MFP",
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_UNICAST_PUB_ACTION,
+	},
+	{
+		.desc = "public action: accept multicast with MFP",
+		.unicast = false,
+		.sta = true,
+		.mfp = true,
+		.result = RX_CONTINUE,
+	},
+	/* protected dual of public action */
+	{
+		.desc = "protected dual: drop unicast from unknown peer",
+		.protected_dual = true,
+		.unicast = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop multicast from unknown peer",
+		.protected_dual = true,
+		.unicast = false,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop unicast without MFP",
+		.protected_dual = true,
+		.unicast = true,
+		.sta = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop multicast without MFP",
+		.protected_dual = true,
+		.unicast = false,
+		.sta = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop undecrypted unicast with MFP",
+		.protected_dual = true,
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: drop undecrypted multicast with MFP",
+		.protected_dual = true,
+		.unicast = false,
+		.sta = true,
+		.mfp = true,
+		.result = RX_DROP_U_UNPROT_DUAL,
+	},
+	{
+		.desc = "protected dual: accept unicast with MFP",
+		.protected_dual = true,
+		.decrypted = true,
+		.unicast = true,
+		.sta = true,
+		.mfp = true,
+		.result = RX_CONTINUE,
+	},
+	{
+		.desc = "protected dual: accept multicast with MFP",
+		.protected_dual = true,
+		.decrypted = true,
+		.unicast = false,
+		.sta = true,
+		.mfp = true,
+		.result = RX_CONTINUE,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(accept_public_action,
+		       accept_public_action_cases,
+		       desc);
+
+static void accept_public_action(struct kunit *test)
+{
+	static struct sta_info sta = {};
+	const struct mfp_test_case *params = test->param_value;
+	struct ieee80211_rx_data rx = {
+		.sta = params->sta ? &sta : NULL,
+	};
+	struct ieee80211_rx_status *status;
+	struct ieee80211_hdr_3addr hdr = {
+		.frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+					     IEEE80211_STYPE_ACTION),
+		.addr1 = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff },
+		.addr2 = { 0x12, 0x22, 0x33, 0x44, 0x55, 0x66 },
+		/* A3/BSSID doesn't matter here */
+	};
+
+	if (!params->sta) {
+		KUNIT_ASSERT_FALSE(test, params->mfp);
+		KUNIT_ASSERT_FALSE(test, params->decrypted);
+	}
+
+	if (params->mfp)
+		set_sta_flag(&sta, WLAN_STA_MFP);
+
+	rx.skb = kunit_zalloc_skb(test, 128, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, rx.skb);
+	status = IEEE80211_SKB_RXCB(rx.skb);
+
+	if (params->decrypted) {
+		status->flag |= RX_FLAG_DECRYPTED;
+		if (params->unicast)
+			hdr.frame_control |=
+				cpu_to_le16(IEEE80211_FCTL_PROTECTED);
+	}
+
+	if (params->unicast)
+		hdr.addr1[0] = 0x02;
+
+	skb_put_data(rx.skb, &hdr, sizeof(hdr));
+
+	if (params->protected_dual)
+		skb_put_u8(rx.skb, WLAN_CATEGORY_PROTECTED_DUAL_OF_ACTION);
+	else
+		skb_put_u8(rx.skb, WLAN_CATEGORY_PUBLIC);
+	skb_put_u8(rx.skb, WLAN_PUB_ACTION_DSE_ENABLEMENT);
+
+	KUNIT_EXPECT_EQ(test,
+			ieee80211_drop_unencrypted_mgmt(&rx),
+			params->result);
+}
+
+static struct kunit_case mfp_test_cases[] = {
+	KUNIT_CASE_PARAM(accept_public_action, accept_public_action_gen_params),
+	{}
+};
+
+static struct kunit_suite mfp = {
+	.name = "mac80211-mfp",
+	.test_cases = mfp_test_cases,
+};
+
+kunit_test_suite(mfp);