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Commit 7b6856a0 authored by Wolfgang Grandegger's avatar Wolfgang Grandegger Committed by David S. Miller
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can: provide library functions for skb allocation 



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: default avatarWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0eae750e

drivers/net/can/at91_can.c

+0 −32
Original line number Diff line number Diff line
@@ -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

 */

drivers/net/can/dev.c

+35 −7
Original line number Diff line number Diff line
@@ -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

 */

drivers/net/can/sja1000/sja1000.c

+2 −10
Original line number Diff line number Diff line
@@ -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 */

drivers/net/can/ti_hecc.c

+4 −13
Original line number Diff line number Diff line
@@ -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) {

drivers/net/can/usb/ems_usb.c

+2 −14
Original line number Diff line number Diff line
@@ -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;