nl80211: Skip interface down/up when setting MAC address

A driver may not support setting MAC address when interface is UP, so
wpa_supplicant used to always sets the interface down for MAC address
change.

Try to change the address first without setting the interface down and
then fall back to DOWN/set addr/UP if the first attempt failed. This can
reduce the interface setup time for time-critical use cases.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index a375c74f7410dea0d9e17f6b238d2069c21819e6..25bae2805cdee1d3171090653fc1257d8a9b92cb 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -11609,6 +11609,15 @@ static int nl80211_set_mac_addr(void *priv, const u8 *addr)
        if (!addr)
                addr = drv->perm_addr;
 
+       /*
+        * Try to change the address first without setting the interface
+        * down and then fall back to DOWN/set addr/UP if the first
+        * attempt failed. This can reduce the interface setup time
+        * significantly with some drivers.
+        */
+       if (!linux_set_ifhwaddr(drv->global->ioctl_sock, bss->ifname, addr))
+               goto done;
+
        if (linux_set_iface_flags(drv->global->ioctl_sock, bss->ifname, 0) < 0)
                return -1;
 
@@ -11625,18 +11634,19 @@ static int nl80211_set_mac_addr(void *priv, const u8 *addr)
                return -1;
        }
 
-       wpa_printf(MSG_DEBUG, "nl80211: set_mac_addr for %s to " MACSTR,
-                  bss->ifname, MAC2STR(addr));
-       drv->addr_changed = new_addr;
-       os_memcpy(bss->prev_addr, bss->addr, ETH_ALEN);
-       os_memcpy(bss->addr, addr, ETH_ALEN);
-
        if (linux_set_iface_flags(drv->global->ioctl_sock, bss->ifname, 1) < 0)
        {
                wpa_printf(MSG_DEBUG,
                           "nl80211: Could not restore interface UP after set_mac_addr");
        }
 
+done:
+       wpa_printf(MSG_DEBUG, "nl80211: set_mac_addr for %s to " MACSTR,
+                  bss->ifname, MAC2STR(addr));
+       drv->addr_changed = new_addr;
+       os_memcpy(bss->prev_addr, bss->addr, ETH_ALEN);
+       os_memcpy(bss->addr, addr, ETH_ALEN);
+
        return 0;
 }