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 _CAN_H
47#define _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 */
72typedef __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 */
83typedef __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 */
104struct 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 */
141struct 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 */
170struct 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 */
194struct 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 */
203