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can: provide library functions for skb allocation

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This patch makes the private functions alloc_can_skb() and
alloc_can_err_skb() of the at91_can driver public and adapts all
drivers to use these. While making the patch I realized, that
the skb's are *not* setup consistently. It's now done as shown
below:

  skb->protocol = htons(ETH_P_CAN);
  skb->pkt_type = PACKET_BROADCAST;
  skb->ip_summed = CHECKSUM_UNNECESSARY;
  *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
  memset(*cf, 0, sizeof(struct can_frame));

The frame is zeroed out to avoid uninitialized data to be passed to
user space. Some drivers or library code did not set "pkt_type" or
"ip_summed". Also,  "__constant_htons()" should not be used for
runtime invocations, as pointed out by David Miller.

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wolfgang Grandegger 2009-10-20 00:08:01 -07:00 • committed by David S. Miller
commit 7b6856a029
6 changed files with 47 additions and 76 deletions
Download patch file Download diff file Expand all files Collapse all files

32
drivers/net/can/at91_can.c
View file

@ -221,38 +221,6 @@ static inline void set_mb_mode(const struct at91_priv *priv, unsigned int mb,
set_mb_mode_prio(priv, mb, mode, 0);
}
static struct sk_buff *alloc_can_skb(struct net_device *dev,
struct can_frame **cf)
{
struct sk_buff *skb;
skb = netdev_alloc_skb(dev, sizeof(struct can_frame));
if (unlikely(!skb))
return NULL;
skb->protocol = htons(ETH_P_CAN);
skb->ip_summed = CHECKSUM_UNNECESSARY;
*cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
return skb;
}
static struct sk_buff *alloc_can_err_skb(struct net_device *dev,
struct can_frame **cf)
{
struct sk_buff *skb;
skb = alloc_can_skb(dev, cf);
if (unlikely(!skb))
return NULL;
memset(*cf, 0, sizeof(struct can_frame));
(*cf)->can_id = CAN_ERR_FLAG;
(*cf)->can_dlc = CAN_ERR_DLC;
return skb;
}
/*
* Swtich transceiver on or off
*/

42
drivers/net/can/dev.c
View file

@ -366,17 +366,12 @@ void can_restart(unsigned long data)
can_flush_echo_skb(dev);
/* send restart message upstream */
skb = dev_alloc_skb(sizeof(struct can_frame));
skb = alloc_can_err_skb(dev, &cf);
if (skb == NULL) {
err = -ENOMEM;
goto restart;
}
skb->dev = dev;
skb->protocol = htons(ETH_P_CAN);
cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
memset(cf, 0, sizeof(struct can_frame));
cf->can_id = CAN_ERR_FLAG | CAN_ERR_RESTARTED;
cf->can_dlc = CAN_ERR_DLC;
cf->can_id |= CAN_ERR_RESTARTED;
netif_rx(skb);
@ -449,6 +444,39 @@ static void can_setup(struct net_device *dev)
dev->features = NETIF_F_NO_CSUM;
}
struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
{
struct sk_buff *skb;
skb = netdev_alloc_skb(dev, sizeof(struct can_frame));
if (unlikely(!skb))
return NULL;
skb->protocol = htons(ETH_P_CAN);
skb->pkt_type = PACKET_BROADCAST;
skb->ip_summed = CHECKSUM_UNNECESSARY;
*cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
memset(*cf, 0, sizeof(struct can_frame));
return skb;
}
EXPORT_SYMBOL_GPL(alloc_can_skb);
struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
{
struct sk_buff *skb;
skb = alloc_can_skb(dev, cf);
if (unlikely(!skb))
return NULL;
(*cf)->can_id = CAN_ERR_FLAG;
(*cf)->can_dlc = CAN_ERR_DLC;
return skb;
}
EXPORT_SYMBOL_GPL(alloc_can_err_skb);
/*
* Allocate and setup space for the CAN network device
*/

12
drivers/net/can/sja1000/sja1000.c
View file

@ -296,11 +296,9 @@ static void sja1000_rx(struct net_device *dev)
uint8_t dlc;
int i;
skb = dev_alloc_skb(sizeof(struct can_frame));
skb = alloc_can_skb(dev, &cf);
if (skb == NULL)
return;
skb->dev = dev;
skb->protocol = htons(ETH_P_CAN);
fi = priv->read_reg(priv, REG_FI);
dlc = fi & 0x0F;
@ -351,15 +349,9 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
enum can_state state = priv->can.state;
uint8_t ecc, alc;
skb = dev_alloc_skb(sizeof(struct can_frame));
skb = alloc_can_err_skb(dev, &cf);
if (skb == NULL)
return -ENOMEM;
skb->dev = dev;
skb->protocol = htons(ETH_P_CAN);
cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
memset(cf, 0, sizeof(struct can_frame));
cf->can_id = CAN_ERR_FLAG;
cf->can_dlc = CAN_ERR_DLC;
if (isrc & IRQ_DOI) {
/* data overrun interrupt */

17
drivers/net/can/ti_hecc.c
View file

@ -535,18 +535,15 @@ static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno)
u32 data, mbx_mask;
unsigned long flags;
skb = netdev_alloc_skb(priv->ndev, sizeof(struct can_frame));
skb = alloc_can_skb(priv->ndev, &cf);
if (!skb) {
if (printk_ratelimit())
dev_err(priv->ndev->dev.parent,
"ti_hecc_rx_pkt: netdev_alloc_skb() failed\n");
"ti_hecc_rx_pkt: alloc_can_skb() failed\n");
return -ENOMEM;
}
skb->protocol = __constant_htons(ETH_P_CAN);
skb->ip_summed = CHECKSUM_UNNECESSARY;
mbx_mask = BIT(mbxno);
cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
data = hecc_read_mbx(priv, mbxno, HECC_CANMID);
if (data & HECC_CANMID_IDE)
cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
@ -656,19 +653,13 @@ static int ti_hecc_error(struct net_device *ndev, int int_status,
struct sk_buff *skb;
/* propogate the error condition to the can stack */
skb = netdev_alloc_skb(ndev, sizeof(struct can_frame));
skb = alloc_can_err_skb(ndev, &cf);
if (!skb) {
if (printk_ratelimit())
dev_err(priv->ndev->dev.parent,
"ti_hecc_error: netdev_alloc_skb() failed\n");
"ti_hecc_error: alloc_can_err_skb() failed\n");
return -ENOMEM;
}
skb->protocol = __constant_htons(ETH_P_CAN);
skb->ip_summed = CHECKSUM_UNNECESSARY;
cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
memset(cf, 0, sizeof(struct can_frame));
cf->can_id = CAN_ERR_FLAG;
cf->can_dlc = CAN_ERR_DLC;
if (int_status & HECC_CANGIF_WLIF) { /* warning level int */
if ((int_status & HECC_CANGIF_BOIF) == 0) {

16
drivers/net/can/usb/ems_usb.c
View file

@ -311,14 +311,10 @@ static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
int i;
struct net_device_stats *stats = &dev->netdev->stats;
skb = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame));
skb = alloc_can_skb(dev->netdev, &cf);
if (skb == NULL)
return;
skb->protocol = htons(ETH_P_CAN);
cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
cf->can_id = msg->msg.can_msg.id;
cf->can_dlc = min_t(u8, msg->msg.can_msg.length, 8);
@ -346,18 +342,10 @@ static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
struct sk_buff *skb;
struct net_device_stats *stats = &dev->netdev->stats;
skb = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame));
skb = alloc_can_err_skb(dev->netdev, &cf);
if (skb == NULL)
return;
skb->protocol = htons(ETH_P_CAN);
cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
memset(cf, 0, sizeof(struct can_frame));
cf->can_id = CAN_ERR_FLAG;
cf->can_dlc = CAN_ERR_DLC;
if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
u8 state = msg->msg.can_state;

4
include/linux/can/dev.h
View file

@ -68,4 +68,8 @@ void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
void can_get_echo_skb(struct net_device *dev, unsigned int idx);
void can_free_echo_skb(struct net_device *dev, unsigned int idx);
struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
struct sk_buff *alloc_can_err_skb(struct net_device *dev,
struct can_frame **cf);
#endif /* CAN_DEV_H */