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1/* SPDX-License-Identifier: ((GPL-2.0-only 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#include <linux/stddef.h> /* for offsetof */
52
53/* controller area network (CAN) kernel definitions */
54
55/* special address description flags for the CAN_ID */
56#define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
57#define CAN_RTR_FLAG 0x40000000U /* remote transmission request */
58#define CAN_ERR_FLAG 0x20000000U /* error message frame */
59
60/* valid bits in CAN ID for frame formats */
61#define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
62#define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */
63#define CAN_ERR_MASK 0x1FFFFFFFU /* omit EFF, RTR, ERR flags */
64#define CANXL_PRIO_MASK CAN_SFF_MASK /* 11 bit priority mask */
65
66/*
67 * Controller Area Network Identifier structure
68 *
69 * bit 0-28 : CAN identifier (11/29 bit)
70 * bit 29 : error message frame flag (0 = data frame, 1 = error message)
71 * bit 30 : remote transmission request flag (1 = rtr frame)
72 * bit 31 : frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
73 */
74typedef __u32 canid_t;
75
76#define CAN_SFF_ID_BITS 11
77#define CAN_EFF_ID_BITS 29
78#define CANXL_PRIO_BITS CAN_SFF_ID_BITS
79
80/*
81 * Controller Area Network Error Message Frame Mask structure
82 *
83 * bit 0-28 : error class mask (see include/uapi/linux/can/error.h)
84 * bit 29-31 : set to zero
85 */
86typedef __u32 can_err_mask_t;
87
88/* CAN payload length and DLC definitions according to ISO 11898-1 */
89#define CAN_MAX_DLC 8
90#define CAN_MAX_RAW_DLC 15
91#define CAN_MAX_DLEN 8
92
93/* CAN FD payload length and DLC definitions according to ISO 11898-7 */
94#define CANFD_MAX_DLC 15
95#define CANFD_MAX_DLEN 64
96
97/*
98 * CAN XL payload length and DLC definitions according to ISO 11898-1
99 * CAN XL DLC ranges from 0 .. 2047 => data length from 1 .. 2048 byte
100 */
101#define CANXL_MIN_DLC 0
102#define CANXL_MAX_DLC 2047
103#define CANXL_MAX_DLC_MASK 0x07FF
104#define CANXL_MIN_DLEN 1
105#define CANXL_MAX_DLEN 2048
106
107/**
108 * struct can_frame - Classical CAN frame structure (aka CAN 2.0B)
109 * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
110 * @len: CAN frame payload length in byte (0 .. 8)
111 * @can_dlc: deprecated name for CAN frame payload length in byte (0 .. 8)
112 * @__pad: padding
113 * @__res0: reserved / padding
114 * @len8_dlc: optional DLC value (9 .. 15) at 8 byte payload length
115 * len8_dlc contains values from 9 .. 15 when the payload length is
116 * 8 bytes but the DLC value (see ISO 11898-1) is greater then 8.
117 * CAN_CTRLMODE_CC_LEN8_DLC flag has to be enabled in CAN driver.
118 * @data: CAN frame payload (up to 8 byte)
119 */
120struct can_frame {
121 canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
122 union {
123 /* CAN frame payload length in byte (0 .. CAN_MAX_DLEN)
124 * was previously named can_dlc so we need to carry that
125 * name for legacy support
126 */
127 __u8 len;
128 __u8 can_dlc; /* deprecated */
129 } __attribute__((packed)); /* disable padding added in some ABIs */
130 __u8 __pad; /* padding */
131 __u8 __res0; /* reserved / padding */
132 __u8 len8_dlc; /* optional DLC for 8 byte payload length (9 .. 15) */
133 __u8 data[CAN_MAX_DLEN] __attribute__((aligned(8)));
134};
135
136/*
137 * defined bits for canfd_frame.flags
138 *
139 * The use of struct canfd_frame implies the FD Frame (FDF) bit to
140 * be set in the CAN frame bitstream on the wire. The FDF bit switch turns
141 * the CAN controllers bitstream processor into the CAN FD mode which creates
142 * two new options within the CAN FD frame specification:
143 *
144 * Bit Rate Switch - to indicate a second bitrate is/was used for the payload
145 * Error State Indicator - represents the error state of the transmitting node
146 *
147 * As the CANFD_ESI bit is internally generated by the transmitting CAN
148 * controller only the CANFD_BRS bit is relevant for real CAN controllers when
149 * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make
150 * sense for virtual CAN interfaces to test applications with echoed frames.
151 *
152 * The struct can_frame and struct canfd_frame intentionally share the same
153 * layout to be able to write CAN frame content into a CAN FD frame structure.
154 * When this is done the former differentiation via CAN_MTU / CANFD_MTU gets
155 * lost. CANFD_FDF allows programmers to mark CAN FD frames in the case of
156 * using struct canfd_frame for mixed CAN / CAN FD content (dual use).
157 * Since the introduction of CAN XL the CANFD_FDF flag is set in all CAN FD
158 * frame structures provided by the CAN subsystem of the Linux kernel.
159 */
160#define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
161#define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
162#define CANFD_FDF 0x04 /* mark CAN FD for dual use of struct canfd_frame */
163
164/**
165 * struct canfd_frame - CAN flexible data rate frame structure
166 * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
167 * @len: frame payload length in byte (0 .. CANFD_MAX_DLEN)
168 * @flags: additional flags for CAN FD
169 * @__res0: reserved / padding
170 * @__res1: reserved / padding
171 * @data: CAN FD frame payload (up to CANFD_MAX_DLEN byte)
172 */
173struct canfd_frame {
174 canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
175 __u8 len; /* frame payload length in byte */
176 __u8 flags; /* additional flags for CAN FD */
177 __u8 __res0; /* reserved / padding */
178 __u8 __res1; /* reserved / padding */
179 __u8 data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
180};
181
182/*
183 * defined bits for canxl_frame.flags
184 *
185 * The canxl_frame.flags element contains three bits CANXL_[XLF|SEC|RRS]
186 * and shares the relative position of the struct can[fd]_frame.len element.
187 * The CANXL_XLF bit ALWAYS needs to be set to indicate a valid CAN XL frame.
188 * As a side effect setting this bit intentionally breaks the length checks
189 * for Classical CAN and CAN FD frames.
190 *
191 * Undefined bits in canxl_frame.flags are reserved and shall be set to zero.
192 */
193#define CANXL_XLF 0x80 /* mandatory CAN XL frame flag (must always be set!) */
194#define CANXL_SEC 0x01 /* Simple Extended Content (security/segmentation) */
195#define CANXL_RRS 0x02 /* Remote Request Substitution */
196
197/* the 8-bit VCID is optionally placed in the canxl_frame.prio element */
198#define CANXL_VCID_OFFSET 16 /* bit offset of VCID in prio element */
199#define CANXL_VCID_VAL_MASK 0xFFUL /* VCID is an 8-bit value */
200#define CANXL_VCID_MASK (CANXL_VCID_VAL_MASK << CANXL_VCID_OFFSET)
201
202/**
203 * struct canxl_frame - CAN with e'X'tended frame 'L'ength frame structure
204 * @prio: 11 bit arbitration priority with zero'ed CAN_*_FLAG flags / VCID
205 * @flags: additional flags for CAN XL
206 * @sdt: SDU (service data unit) type
207 * @len: frame payload length in byte (CANXL_MIN_DLEN .. CANXL_MAX_DLEN)
208 * @af: acceptance field
209 * @data: CAN XL frame payload (CANXL_MIN_DLEN .. CANXL_MAX_DLEN byte)
210 *
211 * @prio shares the same position as @can_id from struct can[fd]_frame.
212 */
213struct canxl_frame {
214 canid_t prio; /* 11 bit priority for arbitration / 8 bit VCID */
215 __u8 flags; /* additional flags for CAN XL */
216 __u8 sdt; /* SDU (service data unit) type */
217 __u16 len; /* frame payload length in byte */
218 __u32 af; /* acceptance field */
219 __u8 data[CANXL_MAX_DLEN];
220};
221
222#define CAN_MTU (sizeof(struct can_frame))
223#define CANFD_MTU (sizeof(struct canfd_frame))
224#define CANXL_MTU (sizeof(struct canxl_frame))
225#define CANXL_HDR_SIZE (offsetof(struct canxl_frame, data))
226#define CANXL_MIN_MTU (CANXL_HDR_SIZE + 64)
227#define CANXL_MAX_MTU CANXL_MTU
228
229/* particular protocols of the protocol family PF_CAN */
230#define CAN_RAW 1 /* RAW sockets */
231#define CAN_BCM 2 /* Broadcast Manager */
232#define CAN_TP16 3 /* VAG Transport Protocol v1.6 */
233#define CAN_TP20 4 /* VAG Transport Protocol v2.0 */
234#define CAN_MCNET 5 /* Bosch MCNet */
235#define CAN_ISOTP 6 /* ISO 15765-2 Transport Protocol */
236#define CAN_J1939 7 /* SAE J1939 */
237#define CAN_NPROTO 8
238
239#define SOL_CAN_BASE 100
240
241/**
242 * struct sockaddr_can - the sockaddr structure for CAN sockets
243 * @can_family: address family number AF_CAN.
244 * @can_ifindex: CAN network interface index.
245 * @can_addr: protocol specific address information
246 */
247struct sockaddr_can {
248 __kernel_sa_family_t can_family;
249 int can_ifindex;
250 union {
251 /* transport protocol class address information (e.g. ISOTP) */
252 struct { canid_t rx_id, tx_id; } tp;
253
254 /* J1939 address information */
255 struct {
256 /* 8 byte name when using dynamic addressing */
257 __u64 name;
258
259 /* pgn:
260 * 8 bit: PS in PDU2 case, else 0
261 * 8 bit: PF
262 * 1 bit: DP
263 * 1 bit: reserved
264 */
265 __u32 pgn;
266
267 /* 1 byte address */
268 __u8 addr;
269 } j1939;
270
271 /* reserved for future CAN protocols address information */
272 } can_addr;
273};
274
275/**
276 * struct can_filter - CAN ID based filter in can_register().
277 * @can_id: relevant bits of CAN ID which are not masked out.
278 * @can_mask: CAN mask (see description)
279 *
280 * Description:
281 * A filter matches, when
282 *
283 * <received_can_id> & mask == can_id & mask
284 *
285 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
286 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
287 */
288struct can_filter {
289 canid_t can_id;
290 canid_t can_mask;
291};
292
293#define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
294
295#endif /* !_UAPI_CAN_H */