[PATCH v2] platform: ignore permanent MAC addresses of all ones (FF:FF:FF:FF:FF:FF)

[Dan Williams <dcbw redhat com>]

Drivers are stupid, and just like the platform ignores an all zeros
permanent address, so should it ignore all ones.

NetworkManager[509]: <debug> [1453743778.854919] [devices/nm-device.c:8885] nm_device_update_hw_address(): 
[0x190370] (eth0): hardware address now 86:18:52:xx:xx:xx
NetworkManager[509]: <debug> [1453743778.855438] [devices/nm-device.c:9138] constructed(): [0x190370] (eth0): 
read initial MAC address 86:18:52:xx:xx:xx
NetworkManager[509]: <debug> [1453743778.861602] [devices/nm-device.c:9148] constructed(): [0x190370] (eth0): 
read permanent MAC address FF:FF:FF:FF:FF:FF
---
 src/platform/nm-platform-utils.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/platform/nm-platform-utils.c b/src/platform/nm-platform-utils.c
index 953ac8c..b0b0b56 100644
--- a/src/platform/nm-platform-utils.c
+++ b/src/platform/nm-platform-utils.c
@@ -142,7 +142,8 @@ nmp_utils_ethtool_get_permanent_address (const char *ifname,
                struct ethtool_perm_addr e;
                guint8 _extra_data[NM_UTILS_HWADDR_LEN_MAX + 1];
        } edata;
-       guint zeros[NM_UTILS_HWADDR_LEN_MAX] = { 0 };
+       static const guint8 zeros[NM_UTILS_HWADDR_LEN_MAX] = { 0 };
+       static guint8 ones[NM_UTILS_HWADDR_LEN_MAX] = { 0 };
 
        if (!ifname)
                return FALSE;
@@ -161,6 +162,12 @@ nmp_utils_ethtool_get_permanent_address (const char *ifname,
        if (memcmp (edata.e.data, zeros, edata.e.size) == 0)
                return FALSE;
 
+       /* Some drivers return a permanent address of all ones. Reject that too */
+       if (G_UNLIKELY (ones[0] != 0xFF))
+               memset (ones, 0xFF, sizeof (ones));
+       if (memcmp (edata.e.data, ones, edata.e.size) == 0)
+               return FALSE;
+
        memcpy (buf, edata.e.data, edata.e.size);
        *length = edata.e.size;
        return TRUE;
-- 
2.4.3