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/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_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 */
203