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 _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/uapi/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_RAW_DLC 15
88 #define CAN_MAX_DLEN 8
89 
90 /* CAN FD payload length and DLC definitions according to ISO 11898-7 */
91 #define CANFD_MAX_DLC 15
92 #define CANFD_MAX_DLEN 64
93 
94 /**
95  * struct can_frame - Classical CAN frame structure (aka CAN 2.0B)
96  * @can_id:   CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
97  * @len:      CAN frame payload length in byte (0 .. 8)
98  * @can_dlc:  deprecated name for CAN frame payload length in byte (0 .. 8)
99  * @__pad:    padding
100  * @__res0:   reserved / padding
101  * @len8_dlc: optional DLC value (9 .. 15) at 8 byte payload length
102  *            len8_dlc contains values from 9 .. 15 when the payload length is
103  *            8 bytes but the DLC value (see ISO 11898-1) is greater then 8.
104  *            CAN_CTRLMODE_CC_LEN8_DLC flag has to be enabled in CAN driver.
105  * @data:     CAN frame payload (up to 8 byte)
106  */
107 struct can_frame {
108 	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
109 	union {
110 		/* CAN frame payload length in byte (0 .. CAN_MAX_DLEN)
111 		 * was previously named can_dlc so we need to carry that
112 		 * name for legacy support
113 		 */
114 		__u8 len;
115 		__u8 can_dlc; /* deprecated */
116 	} __attribute__((packed)); /* disable padding added in some ABIs */
117 	__u8 __pad; /* padding */
118 	__u8 __res0; /* reserved / padding */
119 	__u8 len8_dlc; /* optional DLC for 8 byte payload length (9 .. 15) */
120 	__u8 data[CAN_MAX_DLEN] __attribute__((aligned(8)));
121 };
122 
123 /*
124  * defined bits for canfd_frame.flags
125  *
126  * The use of struct canfd_frame implies the FD Frame (FDF) bit to
127  * be set in the CAN frame bitstream on the wire. The FDF bit switch turns
128  * the CAN controllers bitstream processor into the CAN FD mode which creates
129  * two new options within the CAN FD frame specification:
130  *
131  * Bit Rate Switch - to indicate a second bitrate is/was used for the payload
132  * Error State Indicator - represents the error state of the transmitting node
133  *
134  * As the CANFD_ESI bit is internally generated by the transmitting CAN
135  * controller only the CANFD_BRS bit is relevant for real CAN controllers when
136  * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make
137  * sense for virtual CAN interfaces to test applications with echoed frames.
138  *
139  * The struct can_frame and struct canfd_frame intentionally share the same
140  * layout to be able to write CAN frame content into a CAN FD frame structure.
141  * When this is done the former differentiation via CAN_MTU / CANFD_MTU gets
142  * lost. CANFD_FDF allows programmers to mark CAN FD frames in the case of
143  * using struct canfd_frame for mixed CAN / CAN FD content (dual use).
144  * N.B. the Kernel APIs do NOT provide mixed CAN / CAN FD content inside of
145  * struct canfd_frame therefore the CANFD_FDF flag is disregarded by Linux.
146  */
147 #define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
148 #define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
149 #define CANFD_FDF 0x04 /* mark CAN FD for dual use of struct canfd_frame */
150 
151 /**
152  * struct canfd_frame - CAN flexible data rate frame structure
153  * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
154  * @len:    frame payload length in byte (0 .. CANFD_MAX_DLEN)
155  * @flags:  additional flags for CAN FD
156  * @__res0: reserved / padding
157  * @__res1: reserved / padding
158  * @data:   CAN FD frame payload (up to CANFD_MAX_DLEN byte)
159  */
160 struct canfd_frame {
161 	canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
162 	__u8    len;     /* frame payload length in byte */
163 	__u8    flags;   /* additional flags for CAN FD */
164 	__u8    __res0;  /* reserved / padding */
165 	__u8    __res1;  /* reserved / padding */
166 	__u8    data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
167 };
168 
169 #define CAN_MTU		(sizeof(struct can_frame))
170 #define CANFD_MTU	(sizeof(struct canfd_frame))
171 
172 /* particular protocols of the protocol family PF_CAN */
173 #define CAN_RAW		1 /* RAW sockets */
174 #define CAN_BCM		2 /* Broadcast Manager */
175 #define CAN_TP16	3 /* VAG Transport Protocol v1.6 */
176 #define CAN_TP20	4 /* VAG Transport Protocol v2.0 */
177 #define CAN_MCNET	5 /* Bosch MCNet */
178 #define CAN_ISOTP	6 /* ISO 15765-2 Transport Protocol */
179 #define CAN_J1939	7 /* SAE J1939 */
180 #define CAN_NPROTO	8
181 
182 #define SOL_CAN_BASE 100
183 
184 /**
185  * struct sockaddr_can - the sockaddr structure for CAN sockets
186  * @can_family:  address family number AF_CAN.
187  * @can_ifindex: CAN network interface index.
188  * @can_addr:    protocol specific address information
189  */
190 struct sockaddr_can {
191 	__kernel_sa_family_t can_family;
192 	int         can_ifindex;
193 	union {
194 		/* transport protocol class address information (e.g. ISOTP) */
195 		struct { canid_t rx_id, tx_id; } tp;
196 
197 		/* J1939 address information */
198 		struct {
199 			/* 8 byte name when using dynamic addressing */
200 			__u64 name;
201 
202 			/* pgn:
203 			 * 8 bit: PS in PDU2 case, else 0
204 			 * 8 bit: PF
205 			 * 1 bit: DP
206 			 * 1 bit: reserved
207 			 */
208 			__u32 pgn;
209 
210 			/* 1 byte address */
211 			__u8 addr;
212 		} j1939;
213 
214 		/* reserved for future CAN protocols address information */
215 	} can_addr;
216 };
217 
218 /**
219  * struct can_filter - CAN ID based filter in can_register().
220  * @can_id:   relevant bits of CAN ID which are not masked out.
221  * @can_mask: CAN mask (see description)
222  *
223  * Description:
224  * A filter matches, when
225  *
226  *          <received_can_id> & mask == can_id & mask
227  *
228  * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
229  * filter for error message frames (CAN_ERR_FLAG bit set in mask).
230  */
231 struct can_filter {
232 	canid_t can_id;
233 	canid_t can_mask;
234 };
235 
236 #define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
237 #define CAN_RAW_FILTER_MAX 512 /* maximum number of can_filter set via setsockopt() */
238 
239 #endif /* !_UAPI_CAN_H */
240