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