net: introduce device min_header_len

[mirror_ubuntu-zesty-kernel.git] / include / linux / netdevice.h

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 70ad0291d517b41cd1d4a3c2c7fc046f13e27980..27914672602d9d573e6a3da271cec33ccef51b16 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1511,6 +1511,7 @@ enum netdev_priv_flags {
  *     @max_mtu:       Interface Maximum MTU value
  *     @type:          Interface hardware type
  *     @hard_header_len: Maximum hardware header length.
+ *     @min_header_len:  Minimum hardware header length
  *
  *     @needed_headroom: Extra headroom the hardware may need, but not in all
  *                       cases can this be guaranteed
@@ -1728,6 +1729,7 @@ struct net_device {
        unsigned int            max_mtu;
        unsigned short          type;
        unsigned short          hard_header_len;
+       unsigned short          min_header_len;
 
        unsigned short          needed_headroom;
        unsigned short          needed_tailroom;
@@ -2694,6 +2696,8 @@ static inline bool dev_validate_header(const struct net_device *dev,
 {
        if (likely(len >= dev->hard_header_len))
                return true;
+       if (len < dev->min_header_len)
+               return false;
 
        if (capable(CAP_SYS_RAWIO)) {
                memset(ll_header + len, 0, dev->hard_header_len - len);