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      1 /*
      2  * linux/can.h
      3  *
      4  * Definitions for CAN network layer (socket addr / CAN frame / CAN filter)
      5  *
      6  * Authors: Oliver Hartkopp <oliver.hartkopp (at) volkswagen.de>
      7  *          Urs Thuermann   <urs.thuermann (at) volkswagen.de>
      8  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
      9  * All rights reserved.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. Neither the name of Volkswagen nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * Alternatively, provided that this notice is retained in full, this
     24  * software may be distributed under the terms of the GNU General
     25  * Public License ("GPL") version 2, in which case the provisions of the
     26  * GPL apply INSTEAD OF those given above.
     27  *
     28  * The provided data structures and external interfaces from this code
     29  * are not restricted to be used by modules with a GPL compatible license.
     30  *
     31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     35  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     36  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     37  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     38  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     39  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     40  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     41  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
     42  * DAMAGE.
     43  */
     44 
     45 #ifndef _CAN_H
     46 #define _CAN_H
     47 
     48 #include <linux/types.h>
     49 #include <linux/socket.h>
     50 
     51 /* controller area network (CAN) kernel definitions */
     52 
     53 /* special address description flags for the CAN_ID */
     54 #define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
     55 #define CAN_RTR_FLAG 0x40000000U /* remote transmission request */
     56 #define CAN_ERR_FLAG 0x20000000U /* error message frame */
     57 
     58 /* valid bits in CAN ID for frame formats */
     59 #define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
     60 #define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
     61 #define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */
     62 
     63 /*
     64  * Controller Area Network Identifier structure
     65  *
     66  * bit 0-28	: CAN identifier (11/29 bit)
     67  * bit 29	: error message frame flag (0 = data frame, 1 = error message)
     68  * bit 30	: remote transmission request flag (1 = rtr frame)
     69  * bit 31	: frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
     70  */
     71 typedef __u32 canid_t;
     72 
     73 #define CAN_SFF_ID_BITS		11
     74 #define CAN_EFF_ID_BITS		29
     75 
     76 /*
     77  * Controller Area Network Error Message Frame Mask structure
     78  *
     79  * bit 0-28	: error class mask (see include/linux/can/error.h)
     80  * bit 29-31	: set to zero
     81  */
     82 typedef __u32 can_err_mask_t;
     83 
     84 /* CAN payload length and DLC definitions according to ISO 11898-1 */
     85 #define CAN_MAX_DLC 8
     86 #define CAN_MAX_DLEN 8
     87 
     88 /* CAN FD payload length and DLC definitions according to ISO 11898-7 */
     89 #define CANFD_MAX_DLC 15
     90 #define CANFD_MAX_DLEN 64
     91 
     92 /**
     93  * struct can_frame - basic CAN frame structure
     94  * @can_id:  CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
     95  * @can_dlc: frame payload length in byte (0 .. 8) aka data length code
     96  *           N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1
     97  *           mapping of the 'data length code' to the real payload length
     98  * @__pad:   padding
     99  * @__res0:  reserved / padding
    100  * @__res1:  reserved / padding
    101  * @data:    CAN frame payload (up to 8 byte)
    102  */
    103 struct can_frame {
    104 	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
    105 	__u8    can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */
    106 	__u8    __pad;   /* padding */
    107 	__u8    __res0;  /* reserved / padding */
    108 	__u8    __res1;  /* reserved / padding */
    109 	__u8    data[CAN_MAX_DLEN] __attribute__((aligned(8)));
    110 };
    111 
    112 /*
    113  * defined bits for canfd_frame.flags
    114  *
    115  * The use of struct canfd_frame implies the Extended Data Length (EDL) bit to
    116  * be set in the CAN frame bitstream on the wire. The EDL bit switch turns
    117  * the CAN controllers bitstream processor into the CAN FD mode which creates
    118  * two new options within the CAN FD frame specification:
    119  *
    120  * Bit Rate Switch - to indicate a second bitrate is/was used for the payload
    121  * Error State Indicator - represents the error state of the transmitting node
    122  *
    123  * As the CANFD_ESI bit is internally generated by the transmitting CAN
    124  * controller only the CANFD_BRS bit is relevant for real CAN controllers when
    125  * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make
    126  * sense for virtual CAN interfaces to test applications with echoed frames.
    127  */
    128 #define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
    129 #define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
    130 
    131 /**
    132  * struct canfd_frame - CAN flexible data rate frame structure
    133  * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
    134  * @len:    frame payload length in byte (0 .. CANFD_MAX_DLEN)
    135  * @flags:  additional flags for CAN FD
    136  * @__res0: reserved / padding
    137  * @__res1: reserved / padding
    138  * @data:   CAN FD frame payload (up to CANFD_MAX_DLEN byte)
    139  */
    140 struct canfd_frame {
    141 	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
    142 	__u8    len;     /* frame payload length in byte */
    143 	__u8    flags;   /* additional flags for CAN FD */
    144 	__u8    __res0;  /* reserved / padding */
    145 	__u8    __res1;  /* reserved / padding */
    146 	__u8    data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
    147 };
    148 
    149 #define CAN_MTU		(sizeof(struct can_frame))
    150 #define CANFD_MTU	(sizeof(struct canfd_frame))
    151 
    152 /* particular protocols of the protocol family PF_CAN */
    153 #define CAN_RAW		1 /* RAW sockets */
    154 #define CAN_BCM		2 /* Broadcast Manager */
    155 #define CAN_TP16	3 /* VAG Transport Protocol v1.6 */
    156 #define CAN_TP20	4 /* VAG Transport Protocol v2.0 */
    157 #define CAN_MCNET	5 /* Bosch MCNet */
    158 #define CAN_ISOTP	6 /* ISO 15765-2 Transport Protocol */
    159 #define CAN_NPROTO	7
    160 
    161 #define SOL_CAN_BASE 100
    162 
    163 /**
    164  * struct sockaddr_can - the sockaddr structure for CAN sockets
    165  * @can_family:  address family number AF_CAN.
    166  * @can_ifindex: CAN network interface index.
    167  * @can_addr:    protocol specific address information
    168  */
    169 struct sockaddr_can {
    170 	__kernel_sa_family_t can_family;
    171 	int         can_ifindex;
    172 	union {
    173 		/* transport protocol class address information (e.g. ISOTP) */
    174 		struct { canid_t rx_id, tx_id; } tp;
    175 
    176 		/* reserved for future CAN protocols address information */
    177 	} can_addr;
    178 };
    179 
    180 /**
    181  * struct can_filter - CAN ID based filter in can_register().
    182  * @can_id:   relevant bits of CAN ID which are not masked out.
    183  * @can_mask: CAN mask (see description)
    184  *
    185  * Description:
    186  * A filter matches, when
    187  *
    188  *          <received_can_id> & mask == can_id & mask
    189  *
    190  * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
    191  * filter for error message frames (CAN_ERR_FLAG bit set in mask).
    192  */
    193 struct can_filter {
    194 	canid_t can_id;
    195 	canid_t can_mask;
    196 };
    197 
    198 #define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
    199 
    200 #endif /* !_UAPI_CAN_H */
    201