linux/drivers/net/can/dev/skb.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
 * Copyright (C) 2006 Andrey Volkov, Varma Electronics
 * Copyright (C) 2008-2009 Wolfgang Grandegger <[email protected]>
 */

#include <linux/can/dev.h>
#include <linux/module.h>

#define MOD_DESC …

MODULE_DESCRIPTION(…);
MODULE_LICENSE(…) …;
MODULE_AUTHOR(…) …;

/* Local echo of CAN messages
 *
 * CAN network devices *should* support a local echo functionality
 * (see Documentation/networking/can.rst). To test the handling of CAN
 * interfaces that do not support the local echo both driver types are
 * implemented. In the case that the driver does not support the echo
 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
 * to perform the echo as a fallback solution.
 */
void can_flush_echo_skb(struct net_device *dev)
{ … }

/* Put the skb on the stack to be looped backed locally lateron
 *
 * The function is typically called in the start_xmit function
 * of the device driver. The driver must protect access to
 * priv->echo_skb, if necessary.
 */
int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
		     unsigned int idx, unsigned int frame_len)
{ … }
EXPORT_SYMBOL_GPL(…);

struct sk_buff *
__can_get_echo_skb(struct net_device *dev, unsigned int idx,
		   unsigned int *len_ptr, unsigned int *frame_len_ptr)
{ … }

/* Get the skb from the stack and loop it back locally
 *
 * The function is typically called when the TX done interrupt
 * is handled in the device driver. The driver must protect
 * access to priv->echo_skb, if necessary.
 */
unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx,
			      unsigned int *frame_len_ptr)
{ … }
EXPORT_SYMBOL_GPL(…);

/* Remove the skb from the stack and free it.
 *
 * The function is typically called when TX failed.
 */
void can_free_echo_skb(struct net_device *dev, unsigned int idx,
		       unsigned int *frame_len_ptr)
{ … }
EXPORT_SYMBOL_GPL(…);

/* fill common values for CAN sk_buffs */
static void init_can_skb_reserve(struct sk_buff *skb)
{ … }

struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
{ … }
EXPORT_SYMBOL_GPL(…);

struct sk_buff *alloc_canfd_skb(struct net_device *dev,
				struct canfd_frame **cfd)
{ … }
EXPORT_SYMBOL_GPL(…);

struct sk_buff *alloc_canxl_skb(struct net_device *dev,
				struct canxl_frame **cxl,
				unsigned int data_len)
{ … }
EXPORT_SYMBOL_GPL(…);

struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
{ … }
EXPORT_SYMBOL_GPL(…);

/* Check for outgoing skbs that have not been created by the CAN subsystem */
static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb)
{ … }

/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
{ … }
EXPORT_SYMBOL_GPL(…);