[PATCH] p2p: Fix DBus crash and return additional information for P2P group properties

Angie Chinchilla angie.v.chinchilla at intel.com
Fri Feb 3 19:46:01 EST 2012


From: Todd Previte <toddx.a.previte at intel.com>

When using DBus to get group properties, a segmentation fault is generated on P2P
clients due to a NULL pointer for the ap_iface struct. The current implementation
only returns vendor extensions when called on a P2P group owner.

The code now checks the P2P role which allows for role-specific information to be
provided. This also fixes the crash issue by only looking for the correct structures
based on the current P2P role.

Signed-hostap: Todd Previte <toddx.a.previte at intel.com>
Signed-hostap: Angie Chinchilla <angie.v.chinchilla at intel.com>
---
 wpa_supplicant/dbus/dbus_new_handlers_p2p.c |   80 ++++++++++++++++++++++-----
 1 files changed, 66 insertions(+), 14 deletions(-)

diff --git a/wpa_supplicant/dbus/dbus_new_handlers_p2p.c b/wpa_supplicant/dbus/dbus_new_handlers_p2p.c
index 0f6914c..d621fb2 100644
--- a/wpa_supplicant/dbus/dbus_new_handlers_p2p.c
+++ b/wpa_supplicant/dbus/dbus_new_handlers_p2p.c
@@ -1664,14 +1664,38 @@ dbus_bool_t wpas_dbus_getter_p2p_group_properties(DBusMessageIter *iter,
 {
 	struct wpa_supplicant *wpa_s = user_data;
 	DBusMessageIter variant_iter, dict_iter;
-	struct hostapd_data *hapd = wpa_s->ap_iface->bss[0];
+	struct hostapd_data *hapd = NULL;
 	const struct wpabuf *vendor_ext[MAX_WPS_VENDOR_EXTENSIONS];
 	int num_vendor_ext = 0;
 	int i;
+	u8 role = wpas_get_p2p_role(wpa_s);
+	u16 op_freq = 0;
+	u8 *p_bssid = NULL;
+	char *role_name = NULL;
 
-	if (!hapd) {
-		dbus_set_error_const(error, DBUS_ERROR_FAILED,
-				     "internal error");
+	/* Check current role and adjust information accordingly */
+	switch (role) {
+	case WPAS_P2P_ROLE_CLIENT:
+		/* go_params is only valid for a client */
+		if (wpa_s->go_params) {
+			op_freq = wpa_s->go_params->freq;
+			p_bssid = wpa_s->current_ssid->bssid;
+			role_name = "client";
+		} else
+			return FALSE;
+		break;
+	case WPAS_P2P_ROLE_GO:
+		/* ap_iface is only valid for a GO */
+		if (wpa_s->ap_iface) {
+			hapd = wpa_s->ap_iface->bss[0];
+			p_bssid = hapd->own_addr;
+			op_freq = wpa_s->ap_iface->freq;
+			role_name = "GO";
+		} else
+			return FALSE;
+		break;
+	default:
+		/* Error condition; this should NEVER occur */
 		return FALSE;
 	}
 
@@ -1679,19 +1703,47 @@ dbus_bool_t wpas_dbus_getter_p2p_group_properties(DBusMessageIter *iter,
 					      "a{sv}", &variant_iter) ||
 	    !wpa_dbus_dict_open_write(&variant_iter, &dict_iter))
 		goto err_no_mem;
+	/* Provide the SSID */
+	if (!wpa_dbus_dict_append_byte_array(&dict_iter, "SSID",
+					(const char *)wpa_s->current_ssid->ssid,
+					wpa_s->current_ssid->ssid_len))
+		goto err_no_mem;
+	/* Provide the BSSID */
+	if (!wpa_dbus_dict_append_byte_array(&dict_iter, "BSSID",
+					(const char *)p_bssid, ETH_ALEN))
+		goto err_no_mem;
+	/* Provide the role within the group */
+	if (!wpa_dbus_dict_append_string(&dict_iter, "Role", role_name))
+		goto err_no_mem;
+	/* Provide the operational frequency */
+	if (!wpa_dbus_dict_append_uint16(&dict_iter, "Frequency", op_freq))
+		goto err_no_mem;
 
-	/* Parse WPS Vendor Extensions sent in Beacon/Probe Response */
-	for (i = 0; i < MAX_WPS_VENDOR_EXTENSIONS; i++) {
-		if (hapd->conf->wps_vendor_ext[i] == NULL)
-			continue;
-		vendor_ext[num_vendor_ext++] = hapd->conf->wps_vendor_ext[i];
+	/* Additional information for group owners */
+	if (role == WPAS_P2P_ROLE_GO) {
+		/* Provide the passphrase */
+		if (!wpa_dbus_dict_append_string(&dict_iter, "Passphrase",
+					wpa_s->current_ssid->passphrase))
+			goto err_no_mem;
+		/* Parse WPS Vendor Extensions sent in Beacon/Probe Response */
+		for (i = 0; i < MAX_WPS_VENDOR_EXTENSIONS; i++) {
+			if (hapd->conf->wps_vendor_ext[i] == NULL)
+				continue;
+			vendor_ext[num_vendor_ext++] =
+				hapd->conf->wps_vendor_ext[i];
+		}
+		if (!wpa_dbus_dict_append_wpabuf_array(&dict_iter,
+					"WPSVendorExtensions",
+					vendor_ext, num_vendor_ext))
+			goto err_no_mem;
+	} else {
+		/* If not a GO, provide the PSK */
+		if (!wpa_dbus_dict_append_byte_array(&dict_iter, "PSK",
+					(const char *)wpa_s->current_ssid->psk,
+					32))
+			goto err_no_mem;
 	}
 
-	if (!wpa_dbus_dict_append_wpabuf_array(&dict_iter,
-					       "WPSVendorExtensions",
-					       vendor_ext, num_vendor_ext))
-		goto err_no_mem;
-
 	if (!wpa_dbus_dict_close_write(&variant_iter, &dict_iter) ||
 	    !dbus_message_iter_close_container(iter, &variant_iter))
 		goto err_no_mem;
-- 
1.7.0.4



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