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 ISO 15765-2 CAN transport protocol sockets
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
70struct 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
91struct 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
107struct 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#define CAN_ISOTP_DYN_FC_PARMS 0x2000 /* dynamic FC parameters BS/STmin */
141
142/* protocol machine default values */
143
144#define CAN_ISOTP_DEFAULT_FLAGS 0
145#define CAN_ISOTP_DEFAULT_EXT_ADDRESS 0x00
146#define CAN_ISOTP_DEFAULT_PAD_CONTENT 0xCC /* prevent bit-stuffing */
147#define CAN_ISOTP_DEFAULT_FRAME_TXTIME 50000 /* 50 micro seconds */
148#define CAN_ISOTP_DEFAULT_RECV_BS 0
149#define CAN_ISOTP_DEFAULT_RECV_STMIN 0x00
150#define CAN_ISOTP_DEFAULT_RECV_WFTMAX 0
151
152/*
153 * Remark on CAN_ISOTP_DEFAULT_RECV_* values:
154 *
155 * We can strongly assume, that the Linux Kernel implementation of
156 * CAN_ISOTP is capable to run with BS=0, STmin=0 and WFTmax=0.
157 * But as we like to be able to behave as a commonly available ECU,
158 * these default settings can be changed via sockopts.
159 * For that reason the STmin value is intentionally _not_ checked for
160 * consistency and copied directly into the flow control (FC) frame.
161 */
162
163/* link layer default values => make use of Classical CAN frames */
164
165#define CAN_ISOTP_DEFAULT_LL_MTU CAN_MTU
166#define CAN_ISOTP_DEFAULT_LL_TX_DL CAN_MAX_DLEN
167#define CAN_ISOTP_DEFAULT_LL_TX_FLAGS 0
168
169/*
170 * The CAN_ISOTP_DEFAULT_FRAME_TXTIME has become a non-zero value as
171 * it only makes sense for isotp implementation tests to run without
172 * a N_As value. As user space applications usually do not set the
173 * frame_txtime element of struct can_isotp_options the new in-kernel
174 * default is very likely overwritten with zero when the sockopt()
175 * CAN_ISOTP_OPTS is invoked.
176 * To make sure that a N_As value of zero is only set intentional the
177 * value '0' is now interpreted as 'do not change the current value'.
178 * When a frame_txtime of zero is required for testing purposes this
179 * CAN_ISOTP_FRAME_TXTIME_ZERO u32 value has to be set in frame_txtime.
180 */
181#define CAN_ISOTP_FRAME_TXTIME_ZERO 0xFFFFFFFF
182
183#endif /* !_UAPI_CAN_ISOTP_H */
184

source code of linux/include/uapi/linux/can/isotp.h