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>
This commit is contained in:
Oliver Hartkopp 2010-01-12 02:00:46 -08:00 committed by David S. Miller
parent d218d11133
commit 3ccd4c6167
9 changed files with 41 additions and 13 deletions

View file

@ -342,6 +342,9 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
unsigned int mb, prio;
u32 reg_mid, reg_mcr;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
mb = get_tx_next_mb(priv);
prio = get_tx_next_prio(priv);

View file

@ -318,6 +318,9 @@ static int bfin_can_start_xmit(struct sk_buff *skb, struct net_device *dev)
u16 val;
int i;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
/* fill id */

View file

@ -494,12 +494,8 @@ static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
return NETDEV_TX_BUSY;
}
if (skb->len != sizeof(struct can_frame)) {
dev_err(&spi->dev, "dropping packet - bad length\n");
dev_kfree_skb(skb);
net->stats.tx_dropped++;
if (can_dropped_invalid_skb(net, skb))
return NETDEV_TX_OK;
}
netif_stop_queue(net);
priv->tx_skb = skb;

View file

@ -204,11 +204,8 @@ static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
int i, rtr, buf_id;
u32 can_id;
if (skb->len != sizeof(*frame) || frame->can_dlc > 8) {
kfree_skb(skb);
dev->stats.tx_dropped++;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
}
out_8(&regs->cantier, 0);

View file

@ -249,6 +249,9 @@ static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
uint8_t dreg;
int i;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
fi = dlc = cf->can_dlc;

View file

@ -477,6 +477,9 @@ static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
u32 mbxno, mbx_mask, data;
unsigned long flags;
if (can_dropped_invalid_skb(ndev, skb))
return NETDEV_TX_OK;
mbxno = get_tx_head_mb(priv);
mbx_mask = BIT(mbxno);
spin_lock_irqsave(&priv->mbx_lock, flags);
@ -491,7 +494,6 @@ static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
spin_unlock_irqrestore(&priv->mbx_lock, flags);
/* Prepare mailbox for transmission */
data = min_t(u8, cf->can_dlc, 8);
if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
data |= HECC_CANMCF_RTR;
data |= get_tx_head_prio(priv) << 8;

View file

@ -767,6 +767,9 @@ static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *ne
size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
+ sizeof(struct cpc_can_msg);
if (can_dropped_invalid_skb(netdev, skb))
return NETDEV_TX_OK;
/* create a URB, and a buffer for it, and copy the data to the URB */
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb) {

View file

@ -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;

View file

@ -60,6 +60,21 @@ struct can_priv {
*/
#define get_can_dlc(i) (min_t(__u8, (i), 8))
/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
static inline int can_dropped_invalid_skb(struct net_device *dev,
struct sk_buff *skb)
{
const struct can_frame *cf = (struct can_frame *)skb->data;
if (unlikely(skb->len != sizeof(*cf) || cf->can_dlc > 8)) {
kfree_skb(skb);
dev->stats.tx_dropped++;
return 1;
}
return 0;
}
struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
void free_candev(struct net_device *dev);