include/linux/can/dev.h

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This source file includes following definitions.
can_skb_headroom_valid
can_dropped_invalid_skb
can_is_canfd_skb
can_set_static_ctrlmode
of_can_transceiver
   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * linux/can/dev.h
   4  *
   5  * Definitions for the CAN network device driver interface
   6  *
   7  * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
   8  *               Varma Electronics Oy
   9  *
  10  * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
  11  *
  12  */
  13 
  14 #ifndef _CAN_DEV_H
  15 #define _CAN_DEV_H
  16 
  17 #include <linux/can.h>
  18 #include <linux/can/error.h>
  19 #include <linux/can/led.h>
  20 #include <linux/can/netlink.h>
  21 #include <linux/can/skb.h>
  22 #include <linux/netdevice.h>
  23 
  24 /*
  25  * CAN mode
  26  */
  27 enum can_mode {
  28         CAN_MODE_STOP = 0,
  29         CAN_MODE_START,
  30         CAN_MODE_SLEEP
  31 };
  32 
  33 /*
  34  * CAN common private data
  35  */
  36 struct can_priv {
  37         struct net_device *dev;
  38         struct can_device_stats can_stats;
  39 
  40         struct can_bittiming bittiming, data_bittiming;
  41         const struct can_bittiming_const *bittiming_const,
  42                 *data_bittiming_const;
  43         const u16 *termination_const;
  44         unsigned int termination_const_cnt;
  45         u16 termination;
  46         const u32 *bitrate_const;
  47         unsigned int bitrate_const_cnt;
  48         const u32 *data_bitrate_const;
  49         unsigned int data_bitrate_const_cnt;
  50         u32 bitrate_max;
  51         struct can_clock clock;
  52 
  53         enum can_state state;
  54 
  55         /* CAN controller features - see include/uapi/linux/can/netlink.h */
  56         u32 ctrlmode;           /* current options setting */
  57         u32 ctrlmode_supported; /* options that can be modified by netlink */
  58         u32 ctrlmode_static;    /* static enabled options for driver/hardware */
  59 
  60         int restart_ms;
  61         struct delayed_work restart_work;
  62 
  63         int (*do_set_bittiming)(struct net_device *dev);
  64         int (*do_set_data_bittiming)(struct net_device *dev);
  65         int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
  66         int (*do_set_termination)(struct net_device *dev, u16 term);
  67         int (*do_get_state)(const struct net_device *dev,
  68                             enum can_state *state);
  69         int (*do_get_berr_counter)(const struct net_device *dev,
  70                                    struct can_berr_counter *bec);
  71 
  72         unsigned int echo_skb_max;
  73         struct sk_buff **echo_skb;
  74 
  75 #ifdef CONFIG_CAN_LEDS
  76         struct led_trigger *tx_led_trig;
  77         char tx_led_trig_name[CAN_LED_NAME_SZ];
  78         struct led_trigger *rx_led_trig;
  79         char rx_led_trig_name[CAN_LED_NAME_SZ];
  80         struct led_trigger *rxtx_led_trig;
  81         char rxtx_led_trig_name[CAN_LED_NAME_SZ];
  82 #endif
  83 };
  84 
  85 /*
  86  * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
  87  * to __u8 and ensure the dlc value to be max. 8 bytes.
  88  *
  89  * To be used in the CAN netdriver receive path to ensure conformance with
  90  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  91  */
  92 #define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
  93 #define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))
  94 
  95 /* Check for outgoing skbs that have not been created by the CAN subsystem */
  96 static inline bool can_skb_headroom_valid(struct net_device *dev,
  97                                           struct sk_buff *skb)
  98 {
  99         /* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
 100         if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
 101                 return false;
 102 
 103         /* af_packet does not apply CAN skb specific settings */
 104         if (skb->ip_summed == CHECKSUM_NONE) {
 105                 /* init headroom */
 106                 can_skb_prv(skb)->ifindex = dev->ifindex;
 107                 can_skb_prv(skb)->skbcnt = 0;
 108 
 109                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 110 
 111                 /* preform proper loopback on capable devices */
 112                 if (dev->flags & IFF_ECHO)
 113                         skb->pkt_type = PACKET_LOOPBACK;
 114                 else
 115                         skb->pkt_type = PACKET_HOST;
 116 
 117                 skb_reset_mac_header(skb);
 118                 skb_reset_network_header(skb);
 119                 skb_reset_transport_header(skb);
 120         }
 121 
 122         return true;
 123 }
 124 
 125 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
 126 static inline bool can_dropped_invalid_skb(struct net_device *dev,
 127                                           struct sk_buff *skb)
 128 {
 129         const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 130 
 131         if (skb->protocol == htons(ETH_P_CAN)) {
 132                 if (unlikely(skb->len != CAN_MTU ||
 133                              cfd->len > CAN_MAX_DLEN))
 134                         goto inval_skb;
 135         } else if (skb->protocol == htons(ETH_P_CANFD)) {
 136                 if (unlikely(skb->len != CANFD_MTU ||
 137                              cfd->len > CANFD_MAX_DLEN))
 138                         goto inval_skb;
 139         } else
 140                 goto inval_skb;
 141 
 142         if (!can_skb_headroom_valid(dev, skb))
 143                 goto inval_skb;
 144 
 145         return false;
 146 
 147 inval_skb:
 148         kfree_skb(skb);
 149         dev->stats.tx_dropped++;
 150         return true;
 151 }
 152 
 153 static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 154 {
 155         /* the CAN specific type of skb is identified by its data length */
 156         return skb->len == CANFD_MTU;
 157 }
 158 
 159 /* helper to define static CAN controller features at device creation time */
 160 static inline void can_set_static_ctrlmode(struct net_device *dev,
 161                                            u32 static_mode)
 162 {
 163         struct can_priv *priv = netdev_priv(dev);
 164 
 165         /* alloc_candev() succeeded => netdev_priv() is valid at this point */
 166         priv->ctrlmode = static_mode;
 167         priv->ctrlmode_static = static_mode;
 168 
 169         /* override MTU which was set by default in can_setup()? */
 170         if (static_mode & CAN_CTRLMODE_FD)
 171                 dev->mtu = CANFD_MTU;
 172 }
 173 
 174 /* get data length from can_dlc with sanitized can_dlc */
 175 u8 can_dlc2len(u8 can_dlc);
 176 
 177 /* map the sanitized data length to an appropriate data length code */
 178 u8 can_len2dlc(u8 len);
 179 
 180 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 181                                     unsigned int txqs, unsigned int rxqs);
 182 #define alloc_candev(sizeof_priv, echo_skb_max) \
 183         alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
 184 #define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
 185         alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
 186 void free_candev(struct net_device *dev);
 187 
 188 /* a candev safe wrapper around netdev_priv */
 189 struct can_priv *safe_candev_priv(struct net_device *dev);
 190 
 191 int open_candev(struct net_device *dev);
 192 void close_candev(struct net_device *dev);
 193 int can_change_mtu(struct net_device *dev, int new_mtu);
 194 
 195 int register_candev(struct net_device *dev);
 196 void unregister_candev(struct net_device *dev);
 197 
 198 int can_restart_now(struct net_device *dev);
 199 void can_bus_off(struct net_device *dev);
 200 
 201 void can_change_state(struct net_device *dev, struct can_frame *cf,
 202                       enum can_state tx_state, enum can_state rx_state);
 203 
 204 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 205                       unsigned int idx);
 206 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
 207                                    u8 *len_ptr);
 208 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 209 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 210 
 211 #ifdef CONFIG_OF
 212 void of_can_transceiver(struct net_device *dev);
 213 #else
 214 static inline void of_can_transceiver(struct net_device *dev) { }
 215 #endif
 216 
 217 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 218 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 219                                 struct canfd_frame **cfd);
 220 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
 221                                   struct can_frame **cf);
 222 
 223 #endif /* !_CAN_DEV_H */
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root/include/linux/can/dev.h

INCLUDED FROM

DEFINITIONS
