include/uapi/linux/can.h

   1 /* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
   2 /*
   3  * linux/can.h
   4  *
   5  * Definitions for CAN network layer (socket addr / CAN frame / CAN filter)
   6  *
   7  * Authors: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
   8  *          Urs Thuermann   <urs.thuermann@volkswagen.de>
   9  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
  10  * All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the name of Volkswagen nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * Alternatively, provided that this notice is retained in full, this
  25  * software may be distributed under the terms of the GNU General
  26  * Public License ("GPL") version 2, in which case the provisions of the
  27  * GPL apply INSTEAD OF those given above.
  28  *
  29  * The provided data structures and external interfaces from this code
  30  * are not restricted to be used by modules with a GPL compatible license.
  31  *
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  36  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  37  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  38  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  39  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  40  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  41  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  42  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  43  * DAMAGE.
  44  */
  45
  46 #ifndef _UAPI_CAN_H
  47 #define _UAPI_CAN_H
  48
  49 #include <linux/types.h>
  50 #include <linux/socket.h>
  51
  52 /* controller area network (CAN) kernel definitions */
  53
  54 /* special address description flags for the CAN_ID */
  55 #define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
  56 #define CAN_RTR_FLAG 0x40000000U /* remote transmission request */
  57 #define CAN_ERR_FLAG 0x20000000U /* error message frame */
  58
  59 /* valid bits in CAN ID for frame formats */
  60 #define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
  61 #define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
  62 #define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */
  63
  64 /*
  65  * Controller Area Network Identifier structure
  66  *
  67  * bit 0-28     : CAN identifier (11/29 bit)
  68  * bit 29       : error message frame flag (0 = data frame, 1 = error message)
  69  * bit 30       : remote transmission request flag (1 = rtr frame)
  70  * bit 31       : frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
  71  */
  72 typedef __u32 canid_t;
  73
  74 #define CAN_SFF_ID_BITS         11
  75 #define CAN_EFF_ID_BITS         29
  76
  77 /*
  78  * Controller Area Network Error Message Frame Mask structure
  79  *
  80  * bit 0-28     : error class mask (see include/linux/can/error.h)
  81  * bit 29-31    : set to zero
  82  */
  83 typedef __u32 can_err_mask_t;
  84
  85 /* CAN payload length and DLC definitions according to ISO 11898-1 */
  86 #define CAN_MAX_DLC 8
  87 #define CAN_MAX_DLEN 8
  88
  89 /* CAN FD payload length and DLC definitions according to ISO 11898-7 */
  90 #define CANFD_MAX_DLC 15
  91 #define CANFD_MAX_DLEN 64
  92
  93 /**
  94  * struct can_frame - basic CAN frame structure
  95  * @can_id:  CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
  96  * @can_dlc: frame payload length in byte (0 .. 8) aka data length code
  97  *           N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1
  98  *           mapping of the 'data length code' to the real payload length
  99  * @__pad:   padding
 100  * @__res0:  reserved / padding
 101  * @__res1:  reserved / padding
 102  * @data:    CAN frame payload (up to 8 byte)
 103  */
 104 struct can_frame {
 105         canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
 106         __u8    can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */
 107         __u8    __pad;   /* padding */
 108         __u8    __res0;  /* reserved / padding */
 109         __u8    __res1;  /* reserved / padding */
 110         __u8    data[CAN_MAX_DLEN] __attribute__((aligned(8)));
 111 };
 112
 113 /*
 114  * defined bits for canfd_frame.flags
 115  *
 116  * The use of struct canfd_frame implies the Extended Data Length (EDL) bit to
 117  * be set in the CAN frame bitstream on the wire. The EDL bit switch turns
 118  * the CAN controllers bitstream processor into the CAN FD mode which creates
 119  * two new options within the CAN FD frame specification:
 120  *
 121  * Bit Rate Switch - to indicate a second bitrate is/was used for the payload
 122  * Error State Indicator - represents the error state of the transmitting node
 123  *
 124  * As the CANFD_ESI bit is internally generated by the transmitting CAN
 125  * controller only the CANFD_BRS bit is relevant for real CAN controllers when
 126  * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make
 127  * sense for virtual CAN interfaces to test applications with echoed frames.
 128  */
 129 #define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
 130 #define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
 131
 132 /**
 133  * struct canfd_frame - CAN flexible data rate frame structure
 134  * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
 135  * @len:    frame payload length in byte (0 .. CANFD_MAX_DLEN)
 136  * @flags:  additional flags for CAN FD
 137  * @__res0: reserved / padding
 138  * @__res1: reserved / padding
 139  * @data:   CAN FD frame payload (up to CANFD_MAX_DLEN byte)
 140  */
 141 struct canfd_frame {
 142         canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
 143         __u8    len;     /* frame payload length in byte */
 144         __u8    flags;   /* additional flags for CAN FD */
 145         __u8    __res0;  /* reserved / padding */
 146         __u8    __res1;  /* reserved / padding */
 147         __u8    data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
 148 };
 149
 150 #define CAN_MTU         (sizeof(struct can_frame))
 151 #define CANFD_MTU       (sizeof(struct canfd_frame))
 152
 153 /* particular protocols of the protocol family PF_CAN */
 154 #define CAN_RAW         1 /* RAW sockets */
 155 #define CAN_BCM         2 /* Broadcast Manager */
 156 #define CAN_TP16        3 /* VAG Transport Protocol v1.6 */
 157 #define CAN_TP20        4 /* VAG Transport Protocol v2.0 */
 158 #define CAN_MCNET       5 /* Bosch MCNet */
 159 #define CAN_ISOTP       6 /* ISO 15765-2 Transport Protocol */
 160 #define CAN_NPROTO      7
 161
 162 #define SOL_CAN_BASE 100
 163
 164 /**
 165  * struct sockaddr_can - the sockaddr structure for CAN sockets
 166  * @can_family:  address family number AF_CAN.
 167  * @can_ifindex: CAN network interface index.
 168  * @can_addr:    protocol specific address information
 169  */
 170 struct sockaddr_can {
 171         __kernel_sa_family_t can_family;
 172         int         can_ifindex;
 173         union {
 174                 /* transport protocol class address information (e.g. ISOTP) */
 175                 struct { canid_t rx_id, tx_id; } tp;
 176
 177                 /* reserved for future CAN protocols address information */
 178         } can_addr;
 179 };
 180
 181 /**
 182  * struct can_filter - CAN ID based filter in can_register().
 183  * @can_id:   relevant bits of CAN ID which are not masked out.
 184  * @can_mask: CAN mask (see description)
 185  *
 186  * Description:
 187  * A filter matches, when
 188  *
 189  *          <received_can_id> & mask == can_id & mask
 190  *
 191  * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
 192  * filter for error message frames (CAN_ERR_FLAG bit set in mask).
 193  */
 194 struct can_filter {
 195         canid_t can_id;
 196         canid_t can_mask;
 197 };
 198
 199 #define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
 200 #define CAN_RAW_FILTER_MAX 512 /* maximum number of can_filter set via setsockopt() */
 201
 202 #endif /* !_UAPI_CAN_H */