xref: /openbmc/linux/include/uapi/linux/can/isotp.h (revision 9f39d365)
1 /* SPDX-License-Identifier: ((GPL-2.0-only WITH Linux-syscall-note) OR BSD-3-Clause) */
2 /*
3  * linux/can/isotp.h
4  *
5  * Definitions for isotp CAN sockets (ISO 15765-2:2016)
6  *
7  * Copyright (c) 2020 Volkswagen Group Electronic Research
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of Volkswagen nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * Alternatively, provided that this notice is retained in full, this
23  * software may be distributed under the terms of the GNU General
24  * Public License ("GPL") version 2, in which case the provisions of the
25  * GPL apply INSTEAD OF those given above.
26  *
27  * The provided data structures and external interfaces from this code
28  * are not restricted to be used by modules with a GPL compatible license.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
33  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
36  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
40  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
41  * DAMAGE.
42  */
43 
44 #ifndef _UAPI_CAN_ISOTP_H
45 #define _UAPI_CAN_ISOTP_H
46 
47 #include <linux/types.h>
48 #include <linux/can.h>
49 
50 #define SOL_CAN_ISOTP (SOL_CAN_BASE + CAN_ISOTP)
51 
52 /* for socket options affecting the socket (not the global system) */
53 
54 #define CAN_ISOTP_OPTS		1	/* pass struct can_isotp_options */
55 
56 #define CAN_ISOTP_RECV_FC	2	/* pass struct can_isotp_fc_options */
57 
58 /* sockopts to force stmin timer values for protocol regression tests */
59 
60 #define CAN_ISOTP_TX_STMIN	3	/* pass __u32 value in nano secs    */
61 					/* use this time instead of value   */
62 					/* provided in FC from the receiver */
63 
64 #define CAN_ISOTP_RX_STMIN	4	/* pass __u32 value in nano secs   */
65 					/* ignore received CF frames which */
66 					/* timestamps differ less than val */
67 
68 #define CAN_ISOTP_LL_OPTS	5	/* pass struct can_isotp_ll_options */
69 
70 struct can_isotp_options {
71 
72 	__u32 flags;		/* set flags for isotp behaviour.	*/
73 				/* __u32 value : flags see below	*/
74 
75 	__u32 frame_txtime;	/* frame transmission time (N_As/N_Ar)	*/
76 				/* __u32 value : time in nano secs	*/
77 
78 	__u8  ext_address;	/* set address for extended addressing	*/
79 				/* __u8 value : extended address	*/
80 
81 	__u8  txpad_content;	/* set content of padding byte (tx)	*/
82 				/* __u8 value : content	on tx path	*/
83 
84 	__u8  rxpad_content;	/* set content of padding byte (rx)	*/
85 				/* __u8 value : content	on rx path	*/
86 
87 	__u8  rx_ext_address;	/* set address for extended addressing	*/
88 				/* __u8 value : extended address (rx)	*/
89 };
90 
91 struct can_isotp_fc_options {
92 
93 	__u8  bs;		/* blocksize provided in FC frame	*/
94 				/* __u8 value : blocksize. 0 = off	*/
95 
96 	__u8  stmin;		/* separation time provided in FC frame	*/
97 				/* __u8 value :				*/
98 				/* 0x00 - 0x7F : 0 - 127 ms		*/
99 				/* 0x80 - 0xF0 : reserved		*/
100 				/* 0xF1 - 0xF9 : 100 us - 900 us	*/
101 				/* 0xFA - 0xFF : reserved		*/
102 
103 	__u8  wftmax;		/* max. number of wait frame transmiss.	*/
104 				/* __u8 value : 0 = omit FC N_PDU WT	*/
105 };
106 
107 struct can_isotp_ll_options {
108 
109 	__u8  mtu;		/* generated & accepted CAN frame type	*/
110 				/* __u8 value :				*/
111 				/* CAN_MTU   (16) -> standard CAN 2.0	*/
112 				/* CANFD_MTU (72) -> CAN FD frame	*/
113 
114 	__u8  tx_dl;		/* tx link layer data length in bytes	*/
115 				/* (configured maximum payload length)	*/
116 				/* __u8 value : 8,12,16,20,24,32,48,64	*/
117 				/* => rx path supports all LL_DL values */
118 
119 	__u8  tx_flags;		/* set into struct canfd_frame.flags	*/
120 				/* at frame creation: e.g. CANFD_BRS	*/
121 				/* Obsolete when the BRS flag is fixed	*/
122 				/* by the CAN netdriver configuration	*/
123 };
124 
125 /* flags for isotp behaviour */
126 
127 #define CAN_ISOTP_LISTEN_MODE	0x0001	/* listen only (do not send FC) */
128 #define CAN_ISOTP_EXTEND_ADDR	0x0002	/* enable extended addressing */
129 #define CAN_ISOTP_TX_PADDING	0x0004	/* enable CAN frame padding tx path */
130 #define CAN_ISOTP_RX_PADDING	0x0008	/* enable CAN frame padding rx path */
131 #define CAN_ISOTP_CHK_PAD_LEN	0x0010	/* check received CAN frame padding */
132 #define CAN_ISOTP_CHK_PAD_DATA	0x0020	/* check received CAN frame padding */
133 #define CAN_ISOTP_HALF_DUPLEX	0x0040	/* half duplex error state handling */
134 #define CAN_ISOTP_FORCE_TXSTMIN	0x0080	/* ignore stmin from received FC */
135 #define CAN_ISOTP_FORCE_RXSTMIN	0x0100	/* ignore CFs depending on rx stmin */
136 #define CAN_ISOTP_RX_EXT_ADDR	0x0200	/* different rx extended addressing */
137 #define CAN_ISOTP_WAIT_TX_DONE	0x0400	/* wait for tx completion */
138 #define CAN_ISOTP_SF_BROADCAST	0x0800	/* 1-to-N functional addressing */
139 #define CAN_ISOTP_CF_BROADCAST	0x1000	/* 1-to-N transmission w/o FC */
140 
141 /* protocol machine default values */
142 
143 #define CAN_ISOTP_DEFAULT_FLAGS		0
144 #define CAN_ISOTP_DEFAULT_EXT_ADDRESS	0x00
145 #define CAN_ISOTP_DEFAULT_PAD_CONTENT	0xCC /* prevent bit-stuffing */
146 #define CAN_ISOTP_DEFAULT_FRAME_TXTIME	50000 /* 50 micro seconds */
147 #define CAN_ISOTP_DEFAULT_RECV_BS	0
148 #define CAN_ISOTP_DEFAULT_RECV_STMIN	0x00
149 #define CAN_ISOTP_DEFAULT_RECV_WFTMAX	0
150 
151 /*
152  * Remark on CAN_ISOTP_DEFAULT_RECV_* values:
153  *
154  * We can strongly assume, that the Linux Kernel implementation of
155  * CAN_ISOTP is capable to run with BS=0, STmin=0 and WFTmax=0.
156  * But as we like to be able to behave as a commonly available ECU,
157  * these default settings can be changed via sockopts.
158  * For that reason the STmin value is intentionally _not_ checked for
159  * consistency and copied directly into the flow control (FC) frame.
160  */
161 
162 /* link layer default values => make use of Classical CAN frames */
163 
164 #define CAN_ISOTP_DEFAULT_LL_MTU	CAN_MTU
165 #define CAN_ISOTP_DEFAULT_LL_TX_DL	CAN_MAX_DLEN
166 #define CAN_ISOTP_DEFAULT_LL_TX_FLAGS	0
167 
168 /*
169  * The CAN_ISOTP_DEFAULT_FRAME_TXTIME has become a non-zero value as
170  * it only makes sense for isotp implementation tests to run without
171  * a N_As value. As user space applications usually do not set the
172  * frame_txtime element of struct can_isotp_options the new in-kernel
173  * default is very likely overwritten with zero when the sockopt()
174  * CAN_ISOTP_OPTS is invoked.
175  * To make sure that a N_As value of zero is only set intentional the
176  * value '0' is now interpreted as 'do not change the current value'.
177  * When a frame_txtime of zero is required for testing purposes this
178  * CAN_ISOTP_FRAME_TXTIME_ZERO u32 value has to be set in frame_txtime.
179  */
180 #define CAN_ISOTP_FRAME_TXTIME_ZERO	0xFFFFFFFF
181 
182 #endif /* !_UAPI_CAN_ISOTP_H */
183