scan: Refactor bss_get_supported_ciphers

In many cases the pairwise and group cipher information is not the only
information needed from the BSS RSN/WPA elements in order to make a
decision.  For example, th MFPC/MFPR bits might be needed, or
pre-authentication capability bits, group management ciphers, etc.

This patch refactors bss_get_supported_ciphers into the more general
scan_bss_get_rsn_info function

src/device.c

@@ -220,6 +220,8 @@ static void process_bss(struct device *device, struct scan_bss *bss,
 			struct timespec *timestamp)
 {
 	struct network *network;
+	struct ie_rsn_info info;
+	int r;
 	enum security security;
 	const char *path;
 	double rankmod;
@@ -240,41 +242,20 @@ static void process_bss(struct device *device, struct scan_bss *bss,
 	memcpy(ssid, bss->ssid, bss->ssid_len);
 	ssid[bss->ssid_len] = '\0';
 
-	/*
+	memset(&info, 0, sizeof(info));
-	 * If both an RSN and a WPA elements are present currently
+	r = scan_bss_get_rsn_info(bss, &info);
-	 * RSN takes priority and the WPA IE is ignored.
+	if (r < 0) {
-	 */
+		if (r != -ENOENT)
-	if (bss->rsne) {
-		struct ie_rsn_info rsne;
-		int res = ie_parse_rsne_from_data(bss->rsne, bss->rsne[1] + 2,
-							&rsne);
-		if (res < 0) {
-			l_debug("Cannot parse RSN field (%d, %s)",
-					res, strerror(-res));
 			return;
-		}
 
-		security = scan_get_security(bss->capability, &rsne);
-
-		if (security == SECURITY_PSK)
-			bss->sha256 =
-				rsne.akm_suites & IE_RSN_AKM_SUITE_PSK_SHA256;
-		else if (security == SECURITY_8021X)
-			bss->sha256 =
-				rsne.akm_suites & IE_RSN_AKM_SUITE_8021X_SHA256;
-	} else if (bss->wpa) {
-		struct ie_rsn_info wpa;
-		int res = ie_parse_wpa_from_data(bss->wpa, bss->wpa[1] + 2,
-									&wpa);
-		if (res < 0) {
-			l_debug("Cannot parse WPA IE (%d, %s)",
-						res, strerror(-res));
-			return;
-		}
-
-		security = scan_get_security(bss->capability, &wpa);
-	} else
 		security = scan_get_security(bss->capability, NULL);
+	} else
+		security = scan_get_security(bss->capability, &info);
+
+	if (security == SECURITY_PSK)
+		bss->sha256 = info.akm_suites & IE_RSN_AKM_SUITE_PSK_SHA256;
+	else if (security == SECURITY_8021X)
+		bss->sha256 = info.akm_suites & IE_RSN_AKM_SUITE_8021X_SHA256;
 
 	path = iwd_network_get_path(device, ssid, security);
 
@@ -664,7 +645,7 @@ void device_connect_network(struct device *device, struct network *network,
 	struct eapol_sm *sm = NULL;
 
 	if (security == SECURITY_PSK || security == SECURITY_8021X) {
-		uint16_t pairwise_ciphers, group_ciphers;
+		struct ie_rsn_info bss_info;
 		uint8_t rsne_buf[256];
 		struct ie_rsn_info info;
 
@@ -685,12 +666,13 @@ void device_connect_network(struct device *device, struct network *network,
 				bss->sha256 ? IE_RSN_AKM_SUITE_8021X_SHA256 :
 						IE_RSN_AKM_SUITE_8021X;
 
-		bss_get_supported_ciphers(bss,
+		memset(&bss_info, 0, sizeof(bss_info));
-					&pairwise_ciphers, &group_ciphers);
+		scan_bss_get_rsn_info(bss, &bss_info);
 
 		info.pairwise_ciphers = wiphy_select_cipher(wiphy,
-							pairwise_ciphers);
+						bss_info.pairwise_ciphers);
-		info.group_cipher = wiphy_select_cipher(wiphy, group_ciphers);
+		info.group_cipher = wiphy_select_cipher(wiphy,
+						bss_info.group_cipher);
 
 		/* RSN takes priority */
 		if (bss->rsne) {

src/network.c

@@ -378,15 +378,15 @@ int network_autoconnect(struct network *network, struct scan_bss *bss)
 		break;
 	case SECURITY_PSK:
 	{
-		uint16_t pairwise_ciphers, group_ciphers;
+		struct ie_rsn_info rsn;
 		const char *psk;
 		size_t len;
 
-		bss_get_supported_ciphers(bss,
+		memset(&rsn, 0, sizeof(rsn));
-					&pairwise_ciphers, &group_ciphers);
+		scan_bss_get_rsn_info(bss, &rsn);
 
-		if (!wiphy_select_cipher(wiphy, pairwise_ciphers) ||
+		if (!wiphy_select_cipher(wiphy, rsn.pairwise_ciphers) ||
-				!wiphy_select_cipher(wiphy, group_ciphers)) {
+				!wiphy_select_cipher(wiphy, rsn.group_cipher)) {
 			l_debug("Cipher mis-match");
 			return -ENETUNREACH;
 		}
@@ -487,14 +487,14 @@ struct scan_bss *network_bss_select(struct network *network)
 		for (bss_entry = l_queue_get_entries(bss_list); bss_entry;
 				bss_entry = bss_entry->next) {
 			struct scan_bss *bss = bss_entry->data;
-			uint16_t pairwise_ciphers, group_ciphers;
+			struct ie_rsn_info rsn;
 
-			bss_get_supported_ciphers(bss, &pairwise_ciphers,
+			memset(&rsn, 0, sizeof(rsn));
-							&group_ciphers);
+			scan_bss_get_rsn_info(bss, &rsn);
 
-			if (wiphy_select_cipher(wiphy, pairwise_ciphers) &&
+			if (wiphy_select_cipher(wiphy, rsn.pairwise_ciphers) &&
 					wiphy_select_cipher(wiphy,
-							group_ciphers))
+							rsn.group_cipher))
 				return bss;
 		}
 

src/scan.c

@@ -794,36 +794,32 @@ void scan_bss_free(struct scan_bss *bss)
 	l_free(bss);
 }
 
-void bss_get_supported_ciphers(struct scan_bss *bss,
+int scan_bss_get_rsn_info(struct scan_bss *bss, struct ie_rsn_info *info)
-				uint16_t *pairwise_ciphers,
-				uint16_t *group_ciphers)
 {
-	struct ie_rsn_info ie;
+	/*
-
+	 * If both an RSN and a WPA elements are present currently
-	*pairwise_ciphers = 0;
+	 * RSN takes priority and the WPA IE is ignored.
-	*group_ciphers = 0;
+	 */
-
 	if (bss->rsne) {
 		int res = ie_parse_rsne_from_data(bss->rsne, bss->rsne[1] + 2,
-							&ie);
+							info);
 		if (res < 0) {
 			l_debug("Cannot parse RSN field (%d, %s)",
 					res, strerror(-res));
-			return;
+			return res;
 		}
 	} else if (bss->wpa) {
 		int res = ie_parse_wpa_from_data(bss->wpa, bss->wpa[1] + 2,
-							&ie);
+							info);
 		if (res < 0) {
 			l_debug("Cannot parse WPA IE (%d, %s)",
 					res, strerror(-res));
-			return;
+			return res;
 		}
 	} else
-		return;
+		return -ENOENT;
 
-	*pairwise_ciphers = ie.pairwise_ciphers;
+	return 0;
-	*group_ciphers = ie.group_cipher;
 }
 
 int scan_bss_rank_compare(const void *a, const void *b, void *user_data)

src/scan.h

@@ -82,9 +82,7 @@ enum security scan_get_security(enum ie_bss_capability bss_cap,
 void scan_bss_free(struct scan_bss *bss);
 int scan_bss_rank_compare(const void *a, const void *b, void *user);
 
-void bss_get_supported_ciphers(struct scan_bss *bss,
+int scan_bss_get_rsn_info(struct scan_bss *bss, struct ie_rsn_info *info);
-				uint16_t *pairwise_ciphers,
-				uint16_t *group_ciphers);
 
 uint8_t scan_freq_to_channel(uint32_t freq, enum scan_band *out_band);
 uint32_t scan_channel_to_freq(uint8_t channel, enum scan_band band);