1 files changed, 28 insertions, 4 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2dbb32b988c4..ae2d484416dd 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1459,6 +1459,7 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
         struct net_device *dev;
         __be16 proto = 0;
         int err;
+        int extra_len = 0;
 
         /*
          *      Get and verify the address.
@@ -1493,8 +1494,16 @@ retry:
          * raw protocol and you must do your own fragmentation at this level.
          */
 
+        if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
+                if (!netif_supports_nofcs(dev)) {
+                        err = -EPROTONOSUPPORT;
+                        goto out_unlock;
+                }
+                extra_len = 4; /* We're doing our own CRC */
+        }
+
         err = -EMSGSIZE;
-        if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN)
+        if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
                 goto out_unlock;
 
         if (!skb) {
@@ -1526,7 +1535,7 @@ retry:
                 goto retry;
         }
 
-        if (len > (dev->mtu + dev->hard_header_len)) {
+        if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
                 /* Earlier code assumed this would be a VLAN pkt,
                  * double-check this now that we have the actual
                  * packet in hand.
@@ -1548,6 +1557,9 @@ retry:
         if (err < 0)
                 goto out_unlock;
 
+        if (unlikely(extra_len == 4))
+                skb->no_fcs = 1;
+
         dev_queue_xmit(skb);
         rcu_read_unlock();
         return len;
@@ -2209,6 +2221,7 @@ static int packet_snd(struct socket *sock,
         struct packet_sock *po = pkt_sk(sk);
         unsigned short gso_type = 0;
         int hlen, tlen;
+        int extra_len = 0;
 
         /*
          *      Get and verify the address.
@@ -2288,8 +2301,16 @@ static int packet_snd(struct socket *sock,
                 }
         }
 
+        if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
+                if (!netif_supports_nofcs(dev)) {
+                        err = -EPROTONOSUPPORT;
+                        goto out_unlock;
+                }
+                extra_len = 4; /* We're doing our own CRC */
+        }
+
         err = -EMSGSIZE;
-        if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN))
+        if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
                 goto out_unlock;
 
         err = -ENOBUFS;
@@ -2315,7 +2336,7 @@ static int packet_snd(struct socket *sock,
         if (err < 0)
                 goto out_free;
 
-        if (!gso_type && (len > dev->mtu + reserve)) {
+        if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
                 /* Earlier code assumed this would be a VLAN pkt,
                  * double-check this now that we have the actual
                  * packet in hand.
@@ -2353,6 +2374,9 @@ static int packet_snd(struct socket *sock,
                 len += vnet_hdr_len;
         }
 
+        if (unlikely(extra_len == 4))
+                skb->no_fcs = 1;
+
         /*
          *      Now send it
          */