root/include/linux/can/dev.h

DEFINITIONS

1. can_dropped_invalid_skb
2. can_is_canfd_skb

/*
 * linux/can/dev.h
 *
 * Definitions for the CAN network device driver interface
 *
 * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
 *               Varma Electronics Oy
 *
 * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
 *
 */

#ifndef _CAN_DEV_H
#define _CAN_DEV_H

#include <linux/can.h>
#include <linux/can/netlink.h>
#include <linux/can/error.h>
#include <linux/can/led.h>

/*
 * CAN mode
 */
enum can_mode {
        CAN_MODE_STOP = 0,
        CAN_MODE_START,
        CAN_MODE_SLEEP
};

/*
 * CAN common private data
 */
struct can_priv {
        struct can_device_stats can_stats;

        struct can_bittiming bittiming, data_bittiming;
        const struct can_bittiming_const *bittiming_const,
                *data_bittiming_const;
        struct can_clock clock;

        enum can_state state;
        u32 ctrlmode;
        u32 ctrlmode_supported;

        int restart_ms;
        struct timer_list restart_timer;

        int (*do_set_bittiming)(struct net_device *dev);
        int (*do_set_data_bittiming)(struct net_device *dev);
        int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
        int (*do_get_state)(const struct net_device *dev,
                            enum can_state *state);
        int (*do_get_berr_counter)(const struct net_device *dev,
                                   struct can_berr_counter *bec);

        unsigned int echo_skb_max;
        struct sk_buff **echo_skb;

#ifdef CONFIG_CAN_LEDS
        struct led_trigger *tx_led_trig;
        char tx_led_trig_name[CAN_LED_NAME_SZ];
        struct led_trigger *rx_led_trig;
        char rx_led_trig_name[CAN_LED_NAME_SZ];
#endif
};

/*
 * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
 * to __u8 and ensure the dlc value to be max. 8 bytes.
 *
 * To be used in the CAN netdriver receive path to ensure conformance with
 * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
 */
#define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
#define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))

/* 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 canfd_frame *cfd = (struct canfd_frame *)skb->data;

        if (skb->protocol == htons(ETH_P_CAN)) {
                if (unlikely(skb->len != CAN_MTU ||
                             cfd->len > CAN_MAX_DLEN))
                        goto inval_skb;
        } else if (skb->protocol == htons(ETH_P_CANFD)) {
                if (unlikely(skb->len != CANFD_MTU ||
                             cfd->len > CANFD_MAX_DLEN))
                        goto inval_skb;
        } else
                goto inval_skb;

        return 0;

inval_skb:
        kfree_skb(skb);
        dev->stats.tx_dropped++;
        return 1;
}

static inline bool can_is_canfd_skb(const struct sk_buff *skb)
{
        /* the CAN specific type of skb is identified by its data length */
        return skb->len == CANFD_MTU;
}

/* get data length from can_dlc with sanitized can_dlc */
u8 can_dlc2len(u8 can_dlc);

/* map the sanitized data length to an appropriate data length code */
u8 can_len2dlc(u8 len);

struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
void free_candev(struct net_device *dev);

/* a candev safe wrapper around netdev_priv */
struct can_priv *safe_candev_priv(struct net_device *dev);

int open_candev(struct net_device *dev);
void close_candev(struct net_device *dev);
int can_change_mtu(struct net_device *dev, int new_mtu);

int register_candev(struct net_device *dev);
void unregister_candev(struct net_device *dev);

int can_restart_now(struct net_device *dev);
void can_bus_off(struct net_device *dev);

void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
                      unsigned int idx);
unsigned int 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_canfd_skb(struct net_device *dev,
                                struct canfd_frame **cfd);
struct sk_buff *alloc_can_err_skb(struct net_device *dev,
                                  struct can_frame **cf);

#endif /* !_CAN_DEV_H */