linux-headers (unknown)
       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 _CAN_ISOTP_H
      45  #define _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 */