can: Unify droping of invalid tx skbs and netdev stats

To prevent the CAN drivers to operate on invalid socketbuffers the skbs are
now checked and silently dropped at the xmit-function consistently.

Also the netdev stats are consistently using the CAN data length code (dlc)
for [rx|tx]_bytes now.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c
index 80ac56313981..d124d837ae58 100644
--- a/drivers/net/can/vcan.c
+++ b/drivers/net/can/vcan.c
@@ -47,6 +47,7 @@
 #include <linux/if_arp.h>
 #include <linux/if_ether.h>
 #include <linux/can.h>
+#include <linux/can/dev.h>
 #include <net/rtnetlink.h>
 
 static __initdata const char banner[] =
@@ -70,10 +71,11 @@ MODULE_PARM_DESC(echo, "Echo sent frames (for testing). Default: 0 (Off)");
 
 static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
 {
+        struct can_frame *cf = (struct can_frame *)skb->data;
         struct net_device_stats *stats = &dev->stats;
 
         stats->rx_packets++;
-        stats->rx_bytes += skb->len;
+        stats->rx_bytes += cf->can_dlc;
 
         skb->protocol  = htons(ETH_P_CAN);
         skb->pkt_type  = PACKET_BROADCAST;
@@ -85,11 +87,15 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
 
 static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
 {
+        struct can_frame *cf = (struct can_frame *)skb->data;
         struct net_device_stats *stats = &dev->stats;
         int loop;
 
+        if (can_dropped_invalid_skb(dev, skb))
+                return NETDEV_TX_OK;
+
         stats->tx_packets++;
-        stats->tx_bytes += skb->len;
+        stats->tx_bytes += cf->can_dlc;
 
         /* set flag whether this packet has to be looped back */
         loop = skb->pkt_type == PACKET_LOOPBACK;
@@ -103,7 +109,7 @@ static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
                          * CAN core already did the echo for us
                          */
                         stats->rx_packets++;
-                        stats->rx_bytes += skb->len;
+                        stats->rx_bytes += cf->can_dlc;
                 }
                 kfree_skb(skb);
                 return NETDEV_TX_OK;