P2P: Adding option to manage device drivers creating random MAC addresses

Add option 2 to the p2p_device_random_mac_addr configuration option to
support device drivers which use by default random MAC adresses when
creating a new P2P Device interface (for instance, the BCM2711 80211
wireless device driver included in Raspberry Pi 4 Model B). In such
case, this option allows to create the P2P Device interface correctly
when using P2P permanent groups, enabling wpa_supplicant to reuse the
same MAC address when re-invoking a P2P permanent group.

update_config=1 is required.

Signed-off-by: Ircama <amacri@tiscali.it>

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index a137ba293186698e317a32a8b71ebb3863ad8cf4..fe07f58284587023bca368240120ad6cb0764bc0 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -5261,6 +5261,10 @@ static int nl80211_create_iface_once(struct wpa_driver_nl80211_data *drv,
        if (nla_put_flag(msg, NL80211_ATTR_IFACE_SOCKET_OWNER))
                goto fail;
 
+       if ((addr && iftype == NL80211_IFTYPE_P2P_DEVICE) &&
+           nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, addr))
+               goto fail;
+
        ret = send_and_recv_msgs(drv, msg, handler, arg, NULL, NULL);
        msg = NULL;
        if (ret) {

diff --git a/wpa_supplicant/config.h b/wpa_supplicant/config.h
index 6ce737c03a24bb3875ccd12e9db4e51bbbd3207f..c902ffbfa93b367744012591957c03f4fca9adf5 100644 (file)
--- a/wpa_supplicant/config.h
+++ b/wpa_supplicant/config.h
@@ -1554,9 +1554,31 @@ struct wpa_config {
        /**
         * p2p_device_random_mac_addr - P2P Device MAC address policy default
         *
-        * 0 = use permanent MAC address
+        * 0 = use permanent MAC address (the one set by default by the device
+        *     driver). Notice that, if the device driver is configured to
+        *     always use random MAC addresses, this flag breaks reinvoking a
+        *     persistent group, so flags 1 or 2 should be used instead with
+        *     such drivers if persistent groups are used.
         * 1 = use random MAC address on creating the interface if there is no
-        * persistent groups.
+        *     persistent group. Besides, if a persistent group is created,
+        *     p2p_device_persistent_mac_addr is set to the MAC address of the
+        *     P2P Device interface, so that this address will be subsequently
+        *     used to change the MAC address of the P2P Device interface. With
+        *     no persistent group, the random MAC address is created by
+        *     wpa_supplicant, changing the one set by the device driver.
+        *     The device driver shall support SIOCGIFFLAGS/SIOCSIFFLAGS ioctl
+        *     interface control operations.
+        * 2 = this flag should be used when the device driver uses random MAC
+        *     addresses by default when a P2P Device interface is created.
+        *     If p2p_device_persistent_mac_addr is set, use this MAC address
+        *     on creating the P2P Device interface. If not set, use the
+        *     default method adopted by the device driver (e.g., random MAC
+        *     address). Besides, if a persistent group is created,
+        *     p2p_device_persistent_mac_addr is set to the MAC address of the
+        *     P2P Device interface, so that this address will be subsequently
+        *     used in place of the default address set by the device driver.
+        *     (This option does not need support of SIOCGIFFLAGS/SIOCSIFFLAGS
+        *     ioctl interface control operations and uses NL80211_ATTR_MAC).
         *
         * By default, permanent MAC address is used.
         */

diff --git a/wpa_supplicant/p2p_supplicant.c b/wpa_supplicant/p2p_supplicant.c
index 62a3ea691a9b8750fd9bffe9b79e0d0079ee2ae2..c04e8ec71a15094591ce14f1ef7207103237c7f4 100644 (file)
--- a/wpa_supplicant/p2p_supplicant.c
+++ b/wpa_supplicant/p2p_supplicant.c
@@ -3980,6 +3980,7 @@ int wpas_p2p_add_p2pdev_interface(struct wpa_supplicant *wpa_s,
        char ifname[100];
        char force_name[100];
        int ret;
+       const u8 *if_addr = NULL;
 
        ret = os_snprintf(ifname, sizeof(ifname), P2P_MGMT_DEVICE_PREFIX "%s",
                          wpa_s->ifname);
@@ -3991,7 +3992,12 @@ int wpas_p2p_add_p2pdev_interface(struct wpa_supplicant *wpa_s,
        ifname[IFNAMSIZ - 1] = '\0';
        force_name[0] = '\0';
        wpa_s->pending_interface_type = WPA_IF_P2P_DEVICE;
-       ret = wpa_drv_if_add(wpa_s, WPA_IF_P2P_DEVICE, ifname, NULL, NULL,
+
+       if (wpa_s->conf->p2p_device_random_mac_addr == 2 &&
+           !is_zero_ether_addr(wpa_s->conf->p2p_device_persistent_mac_addr))
+               if_addr = wpa_s->conf->p2p_device_persistent_mac_addr;
+
+       ret = wpa_drv_if_add(wpa_s, WPA_IF_P2P_DEVICE, ifname, if_addr, NULL,
                             force_name, wpa_s->pending_interface_addr, NULL);
        if (ret < 0) {
                wpa_printf(MSG_DEBUG, "P2P: Failed to create P2P Device interface");
@@ -4568,6 +4574,16 @@ int wpas_p2p_mac_setup(struct wpa_supplicant *wpa_s)
        if (wpa_s->conf->p2p_device_random_mac_addr == 0)
                return 0;
 
+       if (wpa_s->conf->p2p_device_random_mac_addr == 2) {
+               if (is_zero_ether_addr(
+                           wpa_s->conf->p2p_device_persistent_mac_addr) &&
+                   !is_zero_ether_addr(wpa_s->own_addr)) {
+                       os_memcpy(wpa_s->conf->p2p_device_persistent_mac_addr,
+                                 wpa_s->own_addr, ETH_ALEN);
+               }
+               return 0;
+       }
+
        if (!wpa_s->conf->ssid) {
                if (random_mac_addr(addr) < 0) {
                        wpa_msg(wpa_s, MSG_INFO,