wifi: cfg80211: add a kunit test for 6 GHz colocated AP parsing

Test a few things around parsing of 6 GHz colocated APs to e.g. ensure
that we are not going to scan for a disabled (affiliated) AP.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://msgid.link/20240129220918.079dc50ab43b.Ide898d9f1d4c26d7e774d6fd0ec57766967d6572@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/core.h

@@ -550,9 +550,53 @@ 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);
 
+/**
+ * struct cfg80211_colocated_ap - colocated AP information
+ *
+ * @list: linked list to all colocated APs
+ * @bssid: BSSID of the reported AP
+ * @ssid: SSID of the reported AP
+ * @ssid_len: length of the ssid
+ * @center_freq: frequency the reported AP is on
+ * @unsolicited_probe: the reported AP is part of an ESS, where all the APs
+ *	that operate in the same channel as the reported AP and that might be
+ *	detected by a STA receiving this frame, are transmitting unsolicited
+ *	Probe Response frames every 20 TUs
+ * @oct_recommended: OCT is recommended to exchange MMPDUs with the reported AP
+ * @same_ssid: the reported AP has the same SSID as the reporting AP
+ * @multi_bss: the reported AP is part of a multiple BSSID set
+ * @transmitted_bssid: the reported AP is the transmitting BSSID
+ * @colocated_ess: all the APs that share the same ESS as the reported AP are
+ *	colocated and can be discovered via legacy bands.
+ * @short_ssid_valid: short_ssid is valid and can be used
+ * @short_ssid: the short SSID for this SSID
+ * @psd_20: The 20MHz PSD EIRP of the primary 20MHz channel for the reported AP
+ */
+struct cfg80211_colocated_ap {
+	struct list_head list;
+	u8 bssid[ETH_ALEN];
+	u8 ssid[IEEE80211_MAX_SSID_LEN];
+	size_t ssid_len;
+	u32 short_ssid;
+	u32 center_freq;
+	u8 unsolicited_probe:1,
+	   oct_recommended:1,
+	   same_ssid:1,
+	   multi_bss:1,
+	   transmitted_bssid:1,
+	   colocated_ess:1,
+	   short_ssid_valid:1;
+	s8 psd_20;
+};
+
 #if IS_ENABLED(CONFIG_CFG80211_KUNIT_TEST)
 #define EXPORT_SYMBOL_IF_CFG80211_KUNIT(sym) EXPORT_SYMBOL_IF_KUNIT(sym)
 #define VISIBLE_IF_CFG80211_KUNIT
+void cfg80211_free_coloc_ap_list(struct list_head *coloc_ap_list);
+
+int cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies,
+				struct list_head *list);
+
 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);

net/wireless/scan.c

@@ -77,45 +77,6 @@ MODULE_PARM_DESC(bss_entries_limit,
 
 #define IEEE80211_SCAN_RESULT_EXPIRE	(30 * HZ)
 
-/**
- * struct cfg80211_colocated_ap - colocated AP information
- *
- * @list: linked list to all colocated aPS
- * @bssid: BSSID of the reported AP
- * @ssid: SSID of the reported AP
- * @ssid_len: length of the ssid
- * @center_freq: frequency the reported AP is on
- * @unsolicited_probe: the reported AP is part of an ESS, where all the APs
- *	that operate in the same channel as the reported AP and that might be
- *	detected by a STA receiving this frame, are transmitting unsolicited
- *	Probe Response frames every 20 TUs
- * @oct_recommended: OCT is recommended to exchange MMPDUs with the reported AP
- * @same_ssid: the reported AP has the same SSID as the reporting AP
- * @multi_bss: the reported AP is part of a multiple BSSID set
- * @transmitted_bssid: the reported AP is the transmitting BSSID
- * @colocated_ess: all the APs that share the same ESS as the reported AP are
- *	colocated and can be discovered via legacy bands.
- * @short_ssid_valid: short_ssid is valid and can be used
- * @short_ssid: the short SSID for this SSID
- * @psd_20: The 20MHz PSD EIRP of the primary 20MHz channel for the reported AP
- */
-struct cfg80211_colocated_ap {
-	struct list_head list;
-	u8 bssid[ETH_ALEN];
-	u8 ssid[IEEE80211_MAX_SSID_LEN];
-	size_t ssid_len;
-	u32 short_ssid;
-	u32 center_freq;
-	u8 unsolicited_probe:1,
-	   oct_recommended:1,
-	   same_ssid:1,
-	   multi_bss:1,
-	   transmitted_bssid:1,
-	   colocated_ess:1,
-	   short_ssid_valid:1;
-	s8 psd_20;
-};
-
 static void bss_free(struct cfg80211_internal_bss *bss)
 {
 	struct cfg80211_bss_ies *ies;
@@ -566,7 +527,8 @@ static int cfg80211_calc_short_ssid(const struct cfg80211_bss_ies *ies,
 	return 0;
 }
 
-static void cfg80211_free_coloc_ap_list(struct list_head *coloc_ap_list)
+VISIBLE_IF_CFG80211_KUNIT void
+cfg80211_free_coloc_ap_list(struct list_head *coloc_ap_list)
 {
 	struct cfg80211_colocated_ap *ap, *tmp_ap;
 
@@ -575,6 +537,7 @@ static void cfg80211_free_coloc_ap_list(struct list_head *coloc_ap_list)
 		kfree(ap);
 	}
 }
+EXPORT_SYMBOL_IF_KUNIT(cfg80211_free_coloc_ap_list);
 
 static int cfg80211_parse_ap_info(struct cfg80211_colocated_ap *entry,
 				  const u8 *pos, u8 length,
@@ -648,8 +611,9 @@ static int cfg80211_parse_ap_info(struct cfg80211_colocated_ap *entry,
 	return 0;
 }
 
-static int cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies,
+VISIBLE_IF_CFG80211_KUNIT int
-				       struct list_head *list)
+cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies,
+			    struct list_head *list)
 {
 	struct ieee80211_neighbor_ap_info *ap_info;
 	const struct element *elem, *ssid_elem;
@@ -746,6 +710,7 @@ error:
 	list_splice_tail(&ap_list, list);
 	return n_coloc;
 }
+EXPORT_SYMBOL_IF_KUNIT(cfg80211_parse_colocated_ap);
 
 static  void cfg80211_scan_req_add_chan(struct cfg80211_scan_request *request,
 					struct ieee80211_channel *chan,

net/wireless/tests/scan.c

@@ -628,6 +628,172 @@ static void test_inform_bss_ml_sta(struct kunit *test)
 	cfg80211_put_bss(wiphy, link_bss);
 }
 
+static struct cfg80211_parse_colocated_ap_case {
+	const char *desc;
+	u8 op_class;
+	u8 channel;
+	struct ieee80211_neighbor_ap_info info;
+	union {
+		struct ieee80211_tbtt_info_ge_11 tbtt_long;
+		struct ieee80211_tbtt_info_7_8_9 tbtt_short;
+	};
+	bool add_junk;
+	bool same_ssid;
+	bool valid;
+} cfg80211_parse_colocated_ap_cases[] = {
+	{
+		.desc = "wrong_band",
+		.info.op_class = 81,
+		.info.channel = 11,
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "wrong_type",
+		/* IEEE80211_AP_INFO_TBTT_HDR_TYPE is in the least significant bits */
+		.info.tbtt_info_hdr = IEEE80211_TBTT_INFO_TYPE_MLD,
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "colocated_invalid_len_short",
+		.info.tbtt_info_len = 6,
+		.tbtt_short = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP |
+				      IEEE80211_RNR_TBTT_PARAMS_SAME_SSID,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "colocated_invalid_len_short_mld",
+		.info.tbtt_info_len = 10,
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = false,
+	},
+	{
+		.desc = "colocated_non_mld",
+		.info.tbtt_info_len = sizeof(struct ieee80211_tbtt_info_7_8_9),
+		.tbtt_short = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP |
+				      IEEE80211_RNR_TBTT_PARAMS_SAME_SSID,
+		},
+		.same_ssid = true,
+		.valid = true,
+	},
+	{
+		.desc = "colocated_non_mld_invalid_bssid",
+		.info.tbtt_info_len = sizeof(struct ieee80211_tbtt_info_7_8_9),
+		.tbtt_short = {
+			.bssid = { 0xff, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP |
+				      IEEE80211_RNR_TBTT_PARAMS_SAME_SSID,
+		},
+		.same_ssid = true,
+		.valid = false,
+	},
+	{
+		.desc = "colocated_mld",
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.valid = true,
+	},
+	{
+		.desc = "colocated_mld",
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+		},
+		.add_junk = true,
+		.valid = false,
+	},
+	{
+		.desc = "colocated_disabled_mld",
+		.tbtt_long = {
+			.bssid = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 },
+			.bss_params = IEEE80211_RNR_TBTT_PARAMS_COLOC_AP,
+			.mld_params.params = cpu_to_le16(IEEE80211_RNR_MLD_PARAMS_DISABLED_LINK),
+		},
+		.valid = false,
+	},
+};
+KUNIT_ARRAY_PARAM_DESC(cfg80211_parse_colocated_ap, cfg80211_parse_colocated_ap_cases, desc)
+
+static void test_cfg80211_parse_colocated_ap(struct kunit *test)
+{
+	const struct cfg80211_parse_colocated_ap_case *params = test->param_value;
+	struct sk_buff *input = kunit_zalloc_skb(test, 1024, GFP_KERNEL);
+	struct cfg80211_bss_ies *ies;
+	struct ieee80211_neighbor_ap_info info;
+	LIST_HEAD(coloc_ap_list);
+	int count;
+
+	KUNIT_ASSERT_NOT_NULL(test, input);
+
+	info = params->info;
+
+	/* Reasonable values for a colocated AP */
+	if (!info.tbtt_info_len)
+		info.tbtt_info_len = sizeof(params->tbtt_long);
+	if (!info.op_class)
+		info.op_class = 131;
+	if (!info.channel)
+		info.channel = 33;
+	/* Zero is the correct default for .btt_info_hdr (one entry, TBTT type) */
+
+	skb_put_u8(input, WLAN_EID_SSID);
+	skb_put_u8(input, 4);
+	skb_put_data(input, "TEST", 4);
+
+	skb_put_u8(input, WLAN_EID_REDUCED_NEIGHBOR_REPORT);
+	skb_put_u8(input, sizeof(info) + info.tbtt_info_len + (params->add_junk ? 3 : 0));
+	skb_put_data(input, &info, sizeof(info));
+	skb_put_data(input, &params->tbtt_long, info.tbtt_info_len);
+
+	if (params->add_junk)
+		skb_put_data(input, "123", 3);
+
+	ies = kunit_kzalloc(test, struct_size(ies, data, input->len), GFP_KERNEL);
+	ies->len = input->len;
+	memcpy(ies->data, input->data, input->len);
+
+	count = cfg80211_parse_colocated_ap(ies, &coloc_ap_list);
+
+	KUNIT_EXPECT_EQ(test, count, params->valid);
+	KUNIT_EXPECT_EQ(test, list_count_nodes(&coloc_ap_list), params->valid);
+
+	if (params->valid && !list_empty(&coloc_ap_list)) {
+		struct cfg80211_colocated_ap *ap;
+
+		ap = list_first_entry(&coloc_ap_list, typeof(*ap), list);
+		if (info.tbtt_info_len <= sizeof(params->tbtt_short))
+			KUNIT_EXPECT_MEMEQ(test, ap->bssid, params->tbtt_short.bssid, ETH_ALEN);
+		else
+			KUNIT_EXPECT_MEMEQ(test, ap->bssid, params->tbtt_long.bssid, ETH_ALEN);
+
+		if (params->same_ssid) {
+			KUNIT_EXPECT_EQ(test, ap->ssid_len, 4);
+			KUNIT_EXPECT_MEMEQ(test, ap->ssid, "TEST", 4);
+		} else {
+			KUNIT_EXPECT_EQ(test, ap->ssid_len, 0);
+		}
+	}
+
+	cfg80211_free_coloc_ap_list(&coloc_ap_list);
+}
+
 static struct kunit_case gen_new_ie_test_cases[] = {
 	KUNIT_CASE_PARAM(test_gen_new_ie, gen_new_ie_gen_params),
 	KUNIT_CASE(test_gen_new_ie_malformed),
@@ -653,3 +819,16 @@ static struct kunit_suite inform_bss = {
 };
 
 kunit_test_suite(inform_bss);
+
+static struct kunit_case scan_6ghz_cases[] = {
+	KUNIT_CASE_PARAM(test_cfg80211_parse_colocated_ap,
+			 cfg80211_parse_colocated_ap_gen_params),
+	{}
+};
+
+static struct kunit_suite scan_6ghz = {
+	.name = "cfg80211-scan-6ghz",
+	.test_cases = scan_6ghz_cases,
+};
+
+kunit_test_suite(scan_6ghz);