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 <socketcan@hartkopp.net> Link: https://lore.kernel.org/r/20200928200404.82229-1-socketcan@hartkopp.net [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 <mkl@pengutronix.de>

Author: hartkopp

MAINTAINERS

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

include/uapi/linux/can/isotp.h

@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: ((GPL-2.0-only WITH Linux-syscall-note) OR BSD-3-Clause) */
+/*
+ * linux/can/isotp.h
+ *
+ * Definitions for isotp CAN sockets (ISO 15765-2:2016)
+ *
+ * Copyright (c) 2020 Volkswagen Group Electronic Research
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ */
+
+#ifndef _UAPI_CAN_ISOTP_H
+#define _UAPI_CAN_ISOTP_H
+
+#include <linux/types.h>
+#include <linux/can.h>
+
+#define SOL_CAN_ISOTP (SOL_CAN_BASE + CAN_ISOTP)
+
+/* for socket options affecting the socket (not the global system) */
+
+#define CAN_ISOTP_OPTS1/* pass struct can_isotp_options */
+
+#define CAN_ISOTP_RECV_FC2/* pass struct can_isotp_fc_options */
+
+/* sockopts to force stmin timer values for protocol regression tests */
+
+#define CAN_ISOTP_TX_STMIN3/* pass __u32 value in nano secs */
+/* use this time instead of value */
+/* provided in FC from the receiver */
+
+#define CAN_ISOTP_RX_STMIN4/* pass __u32 value in nano secs */
+/* ignore received CF frames which */
+/* timestamps differ less than val */
+
+#define CAN_ISOTP_LL_OPTS5/* pass struct can_isotp_ll_options */
+
+struct can_isotp_options {
+
+__u32 flags;/* set flags for isotp behaviour.	*/
+/* __u32 value : flags see below	*/
+
+__u32 frame_txtime;/* frame transmission time (N_As/N_Ar)	*/
+/* __u32 value : time in nano secs	*/
+
+__u8 ext_address;/* set address for extended addressing	*/
+/* __u8 value : extended address	*/
+
+__u8 txpad_content;/* set content of padding byte (tx)	*/
+/* __u8 value : content	on tx path	*/
+
+__u8 rxpad_content;/* set content of padding byte (rx)	*/
+/* __u8 value : content	on rx path	*/
+
+__u8 rx_ext_address;/* set address for extended addressing	*/
+/* __u8 value : extended address (rx)	*/
+};
+
+struct can_isotp_fc_options {
+
+__u8 bs;/* blocksize provided in FC frame	*/
+/* __u8 value : blocksize. 0 = off	*/
+
+__u8 stmin;/* separation time provided in FC frame	*/
+/* __u8 value :	*/
+/* 0x00 - 0x7F : 0 - 127 ms	*/
+/* 0x80 - 0xF0 : reserved	*/
+/* 0xF1 - 0xF9 : 100 us - 900 us	*/
+/* 0xFA - 0xFF : reserved	*/
+
+__u8 wftmax;/* max. number of wait frame transmiss.	*/
+/* __u8 value : 0 = omit FC N_PDU WT	*/
+};
+
+struct can_isotp_ll_options {
+
+__u8 mtu;/* generated & accepted CAN frame type	*/
+/* __u8 value :	*/
+/* CAN_MTU (16) -> standard CAN 2.0	*/
+/* CANFD_MTU (72) -> CAN FD frame	*/
+
+__u8 tx_dl;/* tx link layer data length in bytes	*/
+/* (configured maximum payload length)	*/
+/* __u8 value : 8,12,16,20,24,32,48,64	*/
+/* => rx path supports all LL_DL values */
+
+__u8 tx_flags;/* set into struct canfd_frame.flags	*/
+/* at frame creation: e.g. CANFD_BRS	*/
+/* Obsolete when the BRS flag is fixed	*/
+/* by the CAN netdriver configuration	*/
+};
+
+/* flags for isotp behaviour */
+
+#define CAN_ISOTP_LISTEN_MODE0x001/* listen only (do not send FC) */
+#define CAN_ISOTP_EXTEND_ADDR0x002/* enable extended addressing */
+#define CAN_ISOTP_TX_PADDING0x004/* enable CAN frame padding tx path */
+#define CAN_ISOTP_RX_PADDING0x008/* enable CAN frame padding rx path */
+#define CAN_ISOTP_CHK_PAD_LEN0x010/* check received CAN frame padding */
+#define CAN_ISOTP_CHK_PAD_DATA0x020/* check received CAN frame padding */
+#define CAN_ISOTP_HALF_DUPLEX0x040/* half duplex error state handling */
+#define CAN_ISOTP_FORCE_TXSTMIN0x080/* ignore stmin from received FC */
+#define CAN_ISOTP_FORCE_RXSTMIN0x100/* ignore CFs depending on rx stmin */
+#define CAN_ISOTP_RX_EXT_ADDR0x200/* different rx extended addressing */
+#define CAN_ISOTP_WAIT_TX_DONE0x400/* wait for tx completion */
+
+
+/* default values */
+
+#define CAN_ISOTP_DEFAULT_FLAGS0
+#define CAN_ISOTP_DEFAULT_EXT_ADDRESS0x00
+#define CAN_ISOTP_DEFAULT_PAD_CONTENT0xCC /* prevent bit-stuffing */
+#define CAN_ISOTP_DEFAULT_FRAME_TXTIME0
+#define CAN_ISOTP_DEFAULT_RECV_BS0
+#define CAN_ISOTP_DEFAULT_RECV_STMIN0x00
+#define CAN_ISOTP_DEFAULT_RECV_WFTMAX0
+
+#define CAN_ISOTP_DEFAULT_LL_MTUCAN_MTU
+#define CAN_ISOTP_DEFAULT_LL_TX_DLCAN_MAX_DLEN
+#define CAN_ISOTP_DEFAULT_LL_TX_FLAGS0
+
+/*
+ * Remark on CAN_ISOTP_DEFAULT_RECV_* values:
+ *
+ * We can strongly assume, that the Linux Kernel implementation of
+ * CAN_ISOTP is capable to run with BS=0, STmin=0 and WFTmax=0.
+ * But as we like to be able to behave as a commonly available ECU,
+ * these default settings can be changed via sockopts.
+ * For that reason the STmin value is intentionally _not_ checked for
+ * consistency and copied directly into the flow control (FC) frame.
+ *
+ */
+
+#endif /* !_UAPI_CAN_ISOTP_H */

net/can/Kconfig

@@ -55,6 +55,19 @@ config CAN_GW
 
 source "net/can/j1939/Kconfig"
 
+config CAN_ISOTP
+tristate "ISO 15765-2:2016 CAN transport protocol"
+default y
+help
+ 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.
+
 source "drivers/net/can/Kconfig"
 
 endif

net/can/Makefile

@@ -17,3 +17,6 @@ obj-$(CONFIG_CAN_GW)	+= can-gw.o
 can-gw-y:= gw.o
 
 obj-$(CONFIG_CAN_J1939)+= j1939/
+
+obj-$(CONFIG_CAN_ISOTP)+= can-isotp.o
+can-isotp-y:= isotp.o