c7cd606f60
A valid CAN dataframe can have a data length code (DLC) of 0 .. 8 data bytes. When reading the CAN controllers register the 4-bit value may contain values from 0 .. 15 which may exceed the reserved space in the socket buffer! The ISO 11898-1 Chapter 8.4.2.3 (DLC field) says that register values > 8 should be reduced to 8 without any error reporting or frame drop. This patch introduces a new helper macro to cast a given 4-bit data length code (dlc) to __u8 and ensure the DLC value to be max. 8 bytes. The different handlings in the rx path of the CAN netdevice drivers are fixed. Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net> Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: David S. Miller <davem@davemloft.net>
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/*
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* linux/can/dev.h
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*
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* Definitions for the CAN network device driver interface
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*
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* Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
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* Varma Electronics Oy
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*
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* Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
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*
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* Send feedback to <socketcan-users@lists.berlios.de>
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*/
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#ifndef CAN_DEV_H
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#define CAN_DEV_H
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#include <linux/can/netlink.h>
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#include <linux/can/error.h>
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/*
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* CAN mode
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*/
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enum can_mode {
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CAN_MODE_STOP = 0,
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CAN_MODE_START,
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CAN_MODE_SLEEP
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};
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/*
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* CAN common private data
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*/
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struct can_priv {
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struct can_device_stats can_stats;
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struct can_bittiming bittiming;
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struct can_bittiming_const *bittiming_const;
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struct can_clock clock;
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enum can_state state;
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u32 ctrlmode;
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int restart_ms;
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struct timer_list restart_timer;
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int (*do_set_bittiming)(struct net_device *dev);
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int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
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int (*do_get_state)(const struct net_device *dev,
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enum can_state *state);
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unsigned int echo_skb_max;
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struct sk_buff **echo_skb;
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};
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/*
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* get_can_dlc(value) - helper macro to cast a given data length code (dlc)
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* to __u8 and ensure the dlc value to be max. 8 bytes.
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*
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* To be used in the CAN netdriver receive path to ensure conformance with
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* ISO 11898-1 Chapter 8.4.2.3 (DLC field)
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*/
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#define get_can_dlc(i) (min_t(__u8, (i), 8))
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struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
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void free_candev(struct net_device *dev);
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int open_candev(struct net_device *dev);
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void close_candev(struct net_device *dev);
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int register_candev(struct net_device *dev);
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void unregister_candev(struct net_device *dev);
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int can_restart_now(struct net_device *dev);
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void can_bus_off(struct net_device *dev);
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void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
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unsigned int idx);
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void can_get_echo_skb(struct net_device *dev, unsigned int idx);
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void can_free_echo_skb(struct net_device *dev, unsigned int idx);
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struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
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struct sk_buff *alloc_can_err_skb(struct net_device *dev,
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struct can_frame **cf);
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#endif /* CAN_DEV_H */
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