5 files changed, 20 insertions, 2 deletions

diff --git a/include/asm-generic/socket.h b/include/asm-generic/socket.h
index d9aaac0c36d4..b1bea03274d5 100644
--- a/include/asm-generic/socket.h
+++ b/include/asm-generic/socket.h
@@ -68,4 +68,8 @@
 #define SO_WIFI_STATUS          41
 #define SCM_WIFI_STATUS SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
+
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/include/linux/if.h b/include/linux/if.h
index 06b6ef60c821..f995c663c493 100644
--- a/include/linux/if.h
+++ b/include/linux/if.h
@@ -80,6 +80,8 @@
                                          * skbs on transmit */
 #define IFF_UNICAST_FLT 0x20000         /* Supports unicast filtering   */
 #define IFF_TEAM_PORT   0x40000         /* device used as team port */
+#define IFF_SUPP_NOFCS  0x80000         /* device supports sending custom FCS */
+
 
 #define IF_GET_IFACE    0x0001          /* for querying only */
 #define IF_GET_PROTO    0x0002
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0eac07c95255..f1b7d037c2c5 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1082,7 +1082,8 @@ struct net_device {
         const struct header_ops *header_ops;
 
         unsigned int            flags;  /* interface flags (a la BSD)   */
-        unsigned int            priv_flags; /* Like 'flags' but invisible to userspace. */
+        unsigned int            priv_flags; /* Like 'flags' but invisible to userspace.
+                                             * See if.h for definitions. */
         unsigned short          gflags;
         unsigned short          padded; /* How much padding added by alloc_netdev() */
 
@@ -2650,6 +2651,11 @@ static inline int netif_is_bond_slave(struct net_device *dev)
         return dev->flags & IFF_SLAVE && dev->priv_flags & IFF_BONDING;
 }
 
+static inline bool netif_supports_nofcs(struct net_device *dev)
+{
+        return dev->priv_flags & IFF_SUPP_NOFCS;
+}
+
 extern struct pernet_operations __net_initdata loopback_net_ops;
 
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c11a44ea1bf4..06a4c0fd7bef 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -361,6 +361,7 @@ typedef unsigned char *sk_buff_data_t;
  *              ports.
  *      @wifi_acked_valid: wifi_acked was set
  *      @wifi_acked: whether frame was acked on wifi or not
+ *      @no_fcs:  Request NIC to treat last 4 bytes as Ethernet FCS
  *      @dma_cookie: a cookie to one of several possible DMA operations
  *              done by skb DMA functions
  *      @secmark: security marking
@@ -459,7 +460,8 @@ struct sk_buff {
         __u8                    l4_rxhash:1;
         __u8                    wifi_acked_valid:1;
         __u8                    wifi_acked:1;
-        /* 10/12 bit hole (depending on ndisc_nodetype presence) */
+        __u8                    no_fcs:1;
+        /* 9/11 bit hole (depending on ndisc_nodetype presence) */
         kmemcheck_bitfield_end(flags2);
 
 #ifdef CONFIG_NET_DMA
diff --git a/include/net/sock.h b/include/net/sock.h
index 9c0553b9e451..ba761e7de252 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -615,6 +615,10 @@ enum sock_flags {
         SOCK_RXQ_OVFL,
         SOCK_ZEROCOPY, /* buffers from userspace */
         SOCK_WIFI_STATUS, /* push wifi status to userspace */
+        SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
+                     * Will use last 4 bytes of packet sent from
+                     * user-space instead.
+                     */
 };
 
 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)