linux/can/isotp.h

0001 /* SPDX-License-Identifier: ((GPL-2.0-only WITH Linux-syscall-note) OR BSD-3-Clause) */
0002 /*
0003  * linux/can/isotp.h
0004  *
0005  * Definitions for isotp CAN sockets (ISO 15765-2:2016)
0006  *
0007  * Copyright (c) 2020 Volkswagen Group Electronic Research
0008  * All rights reserved.
0009  *
0010  * Redistribution and use in source and binary forms, with or without
0011  * modification, are permitted provided that the following conditions
0012  * are met:
0013  * 1. Redistributions of source code must retain the above copyright
0014  *    notice, this list of conditions and the following disclaimer.
0015  * 2. Redistributions in binary form must reproduce the above copyright
0016  *    notice, this list of conditions and the following disclaimer in the
0017  *    documentation and/or other materials provided with the distribution.
0018  * 3. Neither the name of Volkswagen nor the names of its contributors
0019  *    may be used to endorse or promote products derived from this software
0020  *    without specific prior written permission.
0021  *
0022  * Alternatively, provided that this notice is retained in full, this
0023  * software may be distributed under the terms of the GNU General
0024  * Public License ("GPL") version 2, in which case the provisions of the
0025  * GPL apply INSTEAD OF those given above.
0026  *
0027  * The provided data structures and external interfaces from this code
0028  * are not restricted to be used by modules with a GPL compatible license.
0029  *
0030  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
0031  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
0032  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
0033  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
0034  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
0035  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
0036  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
0037  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
0038  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
0039  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
0040  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
0041  * DAMAGE.
0042  */
0043
0044 #ifndef _UAPI_CAN_ISOTP_H
0045 #define _UAPI_CAN_ISOTP_H
0046
0047 #include <linux/types.h>
0048 #include <linux/can.h>
0049
0050 #define SOL_CAN_ISOTP (SOL_CAN_BASE + CAN_ISOTP)
0051
0052 /* for socket options affecting the socket (not the global system) */
0053
0054 #define CAN_ISOTP_OPTS      1   /* pass struct can_isotp_options */
0055
0056 #define CAN_ISOTP_RECV_FC   2   /* pass struct can_isotp_fc_options */
0057
0058 /* sockopts to force stmin timer values for protocol regression tests */
0059
0060 #define CAN_ISOTP_TX_STMIN  3   /* pass __u32 value in nano secs    */
0061                     /* use this time instead of value   */
0062                     /* provided in FC from the receiver */
0063
0064 #define CAN_ISOTP_RX_STMIN  4   /* pass __u32 value in nano secs   */
0065                     /* ignore received CF frames which */
0066                     /* timestamps differ less than val */
0067
0068 #define CAN_ISOTP_LL_OPTS   5   /* pass struct can_isotp_ll_options */
0069
0070 struct can_isotp_options {
0071
0072     __u32 flags;        /* set flags for isotp behaviour.   */
0073                 /* __u32 value : flags see below    */
0074
0075     __u32 frame_txtime; /* frame transmission time (N_As/N_Ar)  */
0076                 /* __u32 value : time in nano secs  */
0077
0078     __u8  ext_address;  /* set address for extended addressing  */
0079                 /* __u8 value : extended address    */
0080
0081     __u8  txpad_content;    /* set content of padding byte (tx) */
0082                 /* __u8 value : content on tx path  */
0083
0084     __u8  rxpad_content;    /* set content of padding byte (rx) */
0085                 /* __u8 value : content on rx path  */
0086
0087     __u8  rx_ext_address;   /* set address for extended addressing  */
0088                 /* __u8 value : extended address (rx)   */
0089 };
0090
0091 struct can_isotp_fc_options {
0092
0093     __u8  bs;       /* blocksize provided in FC frame   */
0094                 /* __u8 value : blocksize. 0 = off  */
0095
0096     __u8  stmin;        /* separation time provided in FC frame */
0097                 /* __u8 value :             */
0098                 /* 0x00 - 0x7F : 0 - 127 ms     */
0099                 /* 0x80 - 0xF0 : reserved       */
0100                 /* 0xF1 - 0xF9 : 100 us - 900 us    */
0101                 /* 0xFA - 0xFF : reserved       */
0102
0103     __u8  wftmax;       /* max. number of wait frame transmiss. */
0104                 /* __u8 value : 0 = omit FC N_PDU WT    */
0105 };
0106
0107 struct can_isotp_ll_options {
0108
0109     __u8  mtu;      /* generated & accepted CAN frame type  */
0110                 /* __u8 value :             */
0111                 /* CAN_MTU   (16) -> standard CAN 2.0   */
0112                 /* CANFD_MTU (72) -> CAN FD frame   */
0113
0114     __u8  tx_dl;        /* tx link layer data length in bytes   */
0115                 /* (configured maximum payload length)  */
0116                 /* __u8 value : 8,12,16,20,24,32,48,64  */
0117                 /* => rx path supports all LL_DL values */
0118
0119     __u8  tx_flags;     /* set into struct canfd_frame.flags    */
0120                 /* at frame creation: e.g. CANFD_BRS    */
0121                 /* Obsolete when the BRS flag is fixed  */
0122                 /* by the CAN netdriver configuration   */
0123 };
0124
0125 /* flags for isotp behaviour */
0126
0127 #define CAN_ISOTP_LISTEN_MODE   0x0001  /* listen only (do not send FC) */
0128 #define CAN_ISOTP_EXTEND_ADDR   0x0002  /* enable extended addressing */
0129 #define CAN_ISOTP_TX_PADDING    0x0004  /* enable CAN frame padding tx path */
0130 #define CAN_ISOTP_RX_PADDING    0x0008  /* enable CAN frame padding rx path */
0131 #define CAN_ISOTP_CHK_PAD_LEN   0x0010  /* check received CAN frame padding */
0132 #define CAN_ISOTP_CHK_PAD_DATA  0x0020  /* check received CAN frame padding */
0133 #define CAN_ISOTP_HALF_DUPLEX   0x0040  /* half duplex error state handling */
0134 #define CAN_ISOTP_FORCE_TXSTMIN 0x0080  /* ignore stmin from received FC */
0135 #define CAN_ISOTP_FORCE_RXSTMIN 0x0100  /* ignore CFs depending on rx stmin */
0136 #define CAN_ISOTP_RX_EXT_ADDR   0x0200  /* different rx extended addressing */
0137 #define CAN_ISOTP_WAIT_TX_DONE  0x0400  /* wait for tx completion */
0138 #define CAN_ISOTP_SF_BROADCAST  0x0800  /* 1-to-N functional addressing */
0139 #define CAN_ISOTP_CF_BROADCAST  0x1000  /* 1-to-N transmission w/o FC */
0140
0141 /* protocol machine default values */
0142
0143 #define CAN_ISOTP_DEFAULT_FLAGS     0
0144 #define CAN_ISOTP_DEFAULT_EXT_ADDRESS   0x00
0145 #define CAN_ISOTP_DEFAULT_PAD_CONTENT   0xCC /* prevent bit-stuffing */
0146 #define CAN_ISOTP_DEFAULT_FRAME_TXTIME  50000 /* 50 micro seconds */
0147 #define CAN_ISOTP_DEFAULT_RECV_BS   0
0148 #define CAN_ISOTP_DEFAULT_RECV_STMIN    0x00
0149 #define CAN_ISOTP_DEFAULT_RECV_WFTMAX   0
0150
0151 /*
0152  * Remark on CAN_ISOTP_DEFAULT_RECV_* values:
0153  *
0154  * We can strongly assume, that the Linux Kernel implementation of
0155  * CAN_ISOTP is capable to run with BS=0, STmin=0 and WFTmax=0.
0156  * But as we like to be able to behave as a commonly available ECU,
0157  * these default settings can be changed via sockopts.
0158  * For that reason the STmin value is intentionally _not_ checked for
0159  * consistency and copied directly into the flow control (FC) frame.
0160  */
0161
0162 /* link layer default values => make use of Classical CAN frames */
0163
0164 #define CAN_ISOTP_DEFAULT_LL_MTU    CAN_MTU
0165 #define CAN_ISOTP_DEFAULT_LL_TX_DL  CAN_MAX_DLEN
0166 #define CAN_ISOTP_DEFAULT_LL_TX_FLAGS   0
0167
0168 /*
0169  * The CAN_ISOTP_DEFAULT_FRAME_TXTIME has become a non-zero value as
0170  * it only makes sense for isotp implementation tests to run without
0171  * a N_As value. As user space applications usually do not set the
0172  * frame_txtime element of struct can_isotp_options the new in-kernel
0173  * default is very likely overwritten with zero when the sockopt()
0174  * CAN_ISOTP_OPTS is invoked.
0175  * To make sure that a N_As value of zero is only set intentional the
0176  * value '0' is now interpreted as 'do not change the current value'.
0177  * When a frame_txtime of zero is required for testing purposes this
0178  * CAN_ISOTP_FRAME_TXTIME_ZERO u32 value has to be set in frame_txtime.
0179  */
0180 #define CAN_ISOTP_FRAME_TXTIME_ZERO 0xFFFFFFFF
0181
0182 #endif /* !_UAPI_CAN_ISOTP_H */