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can: add ISO 15765-2:2016 transport protocol
CAN Transport Protocols offer support for segmented Point-to-Point communication between CAN nodes via two defined CAN Identifiers. As CAN frames can only transport a small amount of data bytes (max. 8 bytes for 'classic' CAN and max. 64 bytes for CAN FD) this segmentation is needed to transport longer PDUs as needed e.g. for vehicle diagnosis (UDS, ISO 14229) or IP-over-CAN traffic. This protocol driver implements data transfers according to ISO 15765-2:2016 for 'classic' CAN and CAN FD frame types. Signed-off-by: Oliver Hartkopp <[email protected]> Link: https://lore.kernel.org/r/[email protected] [mkl: Removed "WITH Linux-syscall-note" from isotp.c. Fixed indention, a checkpatch warning and typos. Replaced __u{8,32} by u{8,32}. Removed always false (optlen < 0) check in isotp_setsockopt().] Signed-off-by: Marc Kleine-Budde <[email protected]>
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MAINTAINERS

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@@ -3912,6 +3912,7 @@ F: include/net/netns/can.h
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F: include/uapi/linux/can.h
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F: include/uapi/linux/can/bcm.h
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F: include/uapi/linux/can/gw.h
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F: include/uapi/linux/can/isotp.h
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F: include/uapi/linux/can/raw.h
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F: net/can/
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include/uapi/linux/can/isotp.h

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/* SPDX-License-Identifier: ((GPL-2.0-only WITH Linux-syscall-note) OR BSD-3-Clause) */
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/*
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* linux/can/isotp.h
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*
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* Definitions for isotp CAN sockets (ISO 15765-2:2016)
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*
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* Copyright (c) 2020 Volkswagen Group Electronic Research
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Volkswagen nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* Alternatively, provided that this notice is retained in full, this
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* software may be distributed under the terms of the GNU General
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* Public License ("GPL") version 2, in which case the provisions of the
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* GPL apply INSTEAD OF those given above.
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*
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* The provided data structures and external interfaces from this code
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* are not restricted to be used by modules with a GPL compatible license.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*/
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#ifndef _UAPI_CAN_ISOTP_H
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#define _UAPI_CAN_ISOTP_H
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#include <linux/types.h>
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#include <linux/can.h>
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#define SOL_CAN_ISOTP (SOL_CAN_BASE + CAN_ISOTP)
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/* for socket options affecting the socket (not the global system) */
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#define CAN_ISOTP_OPTS 1 /* pass struct can_isotp_options */
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#define CAN_ISOTP_RECV_FC 2 /* pass struct can_isotp_fc_options */
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/* sockopts to force stmin timer values for protocol regression tests */
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#define CAN_ISOTP_TX_STMIN 3 /* pass __u32 value in nano secs */
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/* use this time instead of value */
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/* provided in FC from the receiver */
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#define CAN_ISOTP_RX_STMIN 4 /* pass __u32 value in nano secs */
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/* ignore received CF frames which */
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/* timestamps differ less than val */
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#define CAN_ISOTP_LL_OPTS 5 /* pass struct can_isotp_ll_options */
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struct can_isotp_options {
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__u32 flags; /* set flags for isotp behaviour. */
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/* __u32 value : flags see below */
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__u32 frame_txtime; /* frame transmission time (N_As/N_Ar) */
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/* __u32 value : time in nano secs */
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__u8 ext_address; /* set address for extended addressing */
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/* __u8 value : extended address */
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__u8 txpad_content; /* set content of padding byte (tx) */
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/* __u8 value : content on tx path */
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__u8 rxpad_content; /* set content of padding byte (rx) */
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/* __u8 value : content on rx path */
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__u8 rx_ext_address; /* set address for extended addressing */
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/* __u8 value : extended address (rx) */
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};
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struct can_isotp_fc_options {
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__u8 bs; /* blocksize provided in FC frame */
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/* __u8 value : blocksize. 0 = off */
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__u8 stmin; /* separation time provided in FC frame */
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/* __u8 value : */
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/* 0x00 - 0x7F : 0 - 127 ms */
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/* 0x80 - 0xF0 : reserved */
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/* 0xF1 - 0xF9 : 100 us - 900 us */
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/* 0xFA - 0xFF : reserved */
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__u8 wftmax; /* max. number of wait frame transmiss. */
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/* __u8 value : 0 = omit FC N_PDU WT */
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};
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struct can_isotp_ll_options {
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__u8 mtu; /* generated & accepted CAN frame type */
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/* __u8 value : */
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/* CAN_MTU (16) -> standard CAN 2.0 */
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/* CANFD_MTU (72) -> CAN FD frame */
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__u8 tx_dl; /* tx link layer data length in bytes */
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/* (configured maximum payload length) */
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/* __u8 value : 8,12,16,20,24,32,48,64 */
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/* => rx path supports all LL_DL values */
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__u8 tx_flags; /* set into struct canfd_frame.flags */
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/* at frame creation: e.g. CANFD_BRS */
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/* Obsolete when the BRS flag is fixed */
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/* by the CAN netdriver configuration */
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};
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/* flags for isotp behaviour */
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#define CAN_ISOTP_LISTEN_MODE 0x001 /* listen only (do not send FC) */
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#define CAN_ISOTP_EXTEND_ADDR 0x002 /* enable extended addressing */
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#define CAN_ISOTP_TX_PADDING 0x004 /* enable CAN frame padding tx path */
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#define CAN_ISOTP_RX_PADDING 0x008 /* enable CAN frame padding rx path */
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#define CAN_ISOTP_CHK_PAD_LEN 0x010 /* check received CAN frame padding */
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#define CAN_ISOTP_CHK_PAD_DATA 0x020 /* check received CAN frame padding */
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#define CAN_ISOTP_HALF_DUPLEX 0x040 /* half duplex error state handling */
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#define CAN_ISOTP_FORCE_TXSTMIN 0x080 /* ignore stmin from received FC */
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#define CAN_ISOTP_FORCE_RXSTMIN 0x100 /* ignore CFs depending on rx stmin */
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#define CAN_ISOTP_RX_EXT_ADDR 0x200 /* different rx extended addressing */
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#define CAN_ISOTP_WAIT_TX_DONE 0x400 /* wait for tx completion */
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/* default values */
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#define CAN_ISOTP_DEFAULT_FLAGS 0
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#define CAN_ISOTP_DEFAULT_EXT_ADDRESS 0x00
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#define CAN_ISOTP_DEFAULT_PAD_CONTENT 0xCC /* prevent bit-stuffing */
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#define CAN_ISOTP_DEFAULT_FRAME_TXTIME 0
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#define CAN_ISOTP_DEFAULT_RECV_BS 0
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#define CAN_ISOTP_DEFAULT_RECV_STMIN 0x00
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#define CAN_ISOTP_DEFAULT_RECV_WFTMAX 0
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#define CAN_ISOTP_DEFAULT_LL_MTU CAN_MTU
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#define CAN_ISOTP_DEFAULT_LL_TX_DL CAN_MAX_DLEN
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#define CAN_ISOTP_DEFAULT_LL_TX_FLAGS 0
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/*
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* Remark on CAN_ISOTP_DEFAULT_RECV_* values:
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*
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* We can strongly assume, that the Linux Kernel implementation of
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* CAN_ISOTP is capable to run with BS=0, STmin=0 and WFTmax=0.
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* But as we like to be able to behave as a commonly available ECU,
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* these default settings can be changed via sockopts.
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* For that reason the STmin value is intentionally _not_ checked for
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* consistency and copied directly into the flow control (FC) frame.
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*
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*/
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#endif /* !_UAPI_CAN_ISOTP_H */

net/can/Kconfig

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source "net/can/j1939/Kconfig"
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config CAN_ISOTP
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tristate "ISO 15765-2:2016 CAN transport protocol"
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default y
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help
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CAN Transport Protocols offer support for segmented Point-to-Point
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communication between CAN nodes via two defined CAN Identifiers.
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As CAN frames can only transport a small amount of data bytes
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(max. 8 bytes for 'classic' CAN and max. 64 bytes for CAN FD) this
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segmentation is needed to transport longer PDUs as needed e.g. for
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vehicle diagnosis (UDS, ISO 14229) or IP-over-CAN traffic.
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This protocol driver implements data transfers according to
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ISO 15765-2:2016 for 'classic' CAN and CAN FD frame types.
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source "drivers/net/can/Kconfig"
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endif

net/can/Makefile

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can-gw-y := gw.o
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obj-$(CONFIG_CAN_J1939) += j1939/
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obj-$(CONFIG_CAN_ISOTP) += can-isotp.o
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can-isotp-y := isotp.o

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