wifi: cfg80211: tests: add some scanning related tests

This adds some scanning related tests, mainly exercising the ML element
parsing and inheritance.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://msgid.link/20231220151952.415232-7-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/core.h

@@ -3,7 +3,7 @@
  * Wireless configuration interface internals.
  *
  * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>
- * Copyright (C) 2018-2022 Intel Corporation
+ * Copyright (C) 2018-2023 Intel Corporation
  */
 #ifndef __NET_WIRELESS_CORE_H
 #define __NET_WIRELESS_CORE_H
@@ -549,4 +549,15 @@ int cfg80211_remove_virtual_intf(struct cfg80211_registered_device *rdev,
 				 struct wireless_dev *wdev);
 void cfg80211_wdev_release_link_bsses(struct wireless_dev *wdev, u16 link_mask);
 
+#if IS_ENABLED(CONFIG_CFG80211_KUNIT_TEST)
+#define EXPORT_SYMBOL_IF_CFG80211_KUNIT(sym) EXPORT_SYMBOL_IF_KUNIT(sym)
+#define VISIBLE_IF_CFG80211_KUNIT
+size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
+			   const u8 *subie, size_t subie_len,
+			   u8 *new_ie, size_t new_ie_len);
+#else
+#define EXPORT_SYMBOL_IF_CFG80211_KUNIT(sym)
+#define VISIBLE_IF_CFG80211_KUNIT static
+#endif /* IS_ENABLED(CONFIG_CFG80211_KUNIT_TEST) */
+
 #endif /* __NET_WIRELESS_CORE_H */

net/wireless/scan.c

@@ -20,6 +20,7 @@
 #include <net/cfg80211.h>
 #include <net/cfg80211-wext.h>
 #include <net/iw_handler.h>
+#include <kunit/visibility.h>
 #include "core.h"
 #include "nl80211.h"
 #include "wext-compat.h"
@@ -303,9 +304,10 @@ static size_t cfg80211_copy_elem_with_frags(const struct element *elem,
 	return *pos - buf;
 }
 
-static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
-				  const u8 *subie, size_t subie_len,
-				  u8 *new_ie, size_t new_ie_len)
+VISIBLE_IF_CFG80211_KUNIT size_t
+cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
+		    const u8 *subie, size_t subie_len,
+		    u8 *new_ie, size_t new_ie_len)
 {
 	const struct element *non_inherit_elem, *parent, *sub;
 	u8 *pos = new_ie;
@@ -413,6 +415,7 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
 
 	return pos - new_ie;
 }
+EXPORT_SYMBOL_IF_CFG80211_KUNIT(cfg80211_gen_new_ie);
 
 static bool is_bss(struct cfg80211_bss *a, const u8 *bssid,
 		   const u8 *ssid, size_t ssid_len)

net/wireless/tests/Makefile

@@ -1,3 +1,3 @@
-cfg80211-tests-y += module.o fragmentation.o
+cfg80211-tests-y += module.o fragmentation.o scan.o util.o
 
 obj-$(CONFIG_CFG80211_KUNIT_TEST) += cfg80211-tests.o

net/wireless/tests/util.c

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KUnit fixture to have a (configurable) wiphy
+ *
+ * Copyright (C) 2023 Intel Corporation
+ */
+#include <linux/ieee80211.h>
+#include <net/cfg80211.h>
+#include <kunit/test.h>
+#include <kunit/test-bug.h>
+#include "util.h"
+
+int t_wiphy_init(struct kunit_resource *resource, void *ctx)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct cfg80211_ops *ops;
+	struct wiphy *wiphy;
+	struct t_wiphy_priv *priv;
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ops);
+
+	wiphy = wiphy_new_nm(ops, sizeof(*priv), "kunit");
+	KUNIT_ASSERT_NOT_NULL(test, wiphy);
+
+	priv = wiphy_priv(wiphy);
+	priv->ctx = ctx;
+	priv->ops = ops;
+
+	/* Initialize channels, feel free to add more here channels/bands */
+	memcpy(priv->channels_2ghz, channels_2ghz, sizeof(channels_2ghz));
+	wiphy->bands[NL80211_BAND_2GHZ] = &priv->band_2ghz;
+	priv->band_2ghz.channels = priv->channels_2ghz;
+	priv->band_2ghz.n_channels = ARRAY_SIZE(channels_2ghz);
+
+	resource->data = wiphy;
+	resource->name = "wiphy";
+
+	return 0;
+}
+
+void t_wiphy_exit(struct kunit_resource *resource)
+{
+	struct t_wiphy_priv *priv;
+	struct cfg80211_ops *ops;
+
+	priv = wiphy_priv(resource->data);
+	ops = priv->ops;
+
+	/* Should we ensure anything about the state here?
+	 * e.g. full destruction or no calls to any ops on destruction?
+	 */
+
+	wiphy_free(resource->data);
+	kfree(ops);
+}

net/wireless/tests/util.h

@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Utilities for cfg80211 unit testing
+ *
+ * Copyright (C) 2023 Intel Corporation
+ */
+#ifndef __CFG80211_UTILS_H
+#define __CFG80211_UTILS_H
+
+#define CHAN2G(_freq)  { \
+	.band = NL80211_BAND_2GHZ, \
+	.center_freq = (_freq), \
+	.hw_value = (_freq), \
+}
+
+static const struct ieee80211_channel channels_2ghz[] = {
+	CHAN2G(2412), /* Channel 1 */
+	CHAN2G(2417), /* Channel 2 */
+	CHAN2G(2422), /* Channel 3 */
+	CHAN2G(2427), /* Channel 4 */
+	CHAN2G(2432), /* Channel 5 */
+	CHAN2G(2437), /* Channel 6 */
+	CHAN2G(2442), /* Channel 7 */
+	CHAN2G(2447), /* Channel 8 */
+	CHAN2G(2452), /* Channel 9 */
+	CHAN2G(2457), /* Channel 10 */
+	CHAN2G(2462), /* Channel 11 */
+	CHAN2G(2467), /* Channel 12 */
+	CHAN2G(2472), /* Channel 13 */
+	CHAN2G(2484), /* Channel 14 */
+};
+
+struct t_wiphy_priv {
+	struct kunit *test;
+	struct cfg80211_ops *ops;
+
+	void *ctx;
+
+	struct ieee80211_supported_band band_2ghz;
+	struct ieee80211_channel channels_2ghz[ARRAY_SIZE(channels_2ghz)];
+};
+
+#define T_WIPHY(test, ctx) ({						\
+		struct wiphy *__wiphy =					\
+			kunit_alloc_resource(test, t_wiphy_init,	\
+					     t_wiphy_exit,		\
+					     GFP_KERNEL, &(ctx));	\
+									\
+		KUNIT_ASSERT_NOT_NULL(test, __wiphy);			\
+		__wiphy;						\
+	})
+#define t_wiphy_ctx(wiphy) (((struct t_wiphy_priv *)wiphy_priv(wiphy))->ctx)
+
+int t_wiphy_init(struct kunit_resource *resource, void *data);
+void t_wiphy_exit(struct kunit_resource *resource);
+
+#define t_skb_remove_member(skb, type, member)	do {				\
+		memmove((skb)->data + (skb)->len - sizeof(type) +		\
+			offsetof(type, member),					\
+			(skb)->data + (skb)->len - sizeof(type) +		\
+			offsetofend(type, member),				\
+			offsetofend(type, member));				\
+		skb_trim(skb, (skb)->len - sizeof_field(type, member));		\
+	} while (0)
+
+#endif /* __CFG80211_UTILS_H */