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>
---
 drivers/net/can/at91_can.c        |   32 ----------------------------
 drivers/net/can/dev.c             |   42 +++++++++++++++++++++++++++++++-------
 drivers/net/can/sja1000/sja1000.c |   12 +---------
 drivers/net/can/ti_hecc.c         |   17 +++------------
 drivers/net/can/usb/ems_usb.c     |   16 +-------------
 include/linux/can/dev.h           |    4 +++
 6 files changed, 47 insertions(+), 76 deletions(-)

Index: net-next-2.6/drivers/net/can/dev.c
===================================================================
--- net-next-2.6.orig/drivers/net/can/dev.c
+++ net-next-2.6/drivers/net/can/dev.c
@@ -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 ...
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From: Wolfgang Grandegger <wg@grandegger.com>

Wow, it builds, applied :-)
--

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