commit 9f3caa6fe376474a1b6e2caef1f30f1c4f008ebd
Author: Oliver Hartkopp <socketcan@hartkopp.net>
Date:   Sat Apr 22 12:36:05 2017 +0200

    Initial commit based on https://github.com/downwith/linux-isotp
    
    This repository contains a rework to simplify the build of the former ISO-TP
    development repository at https://github.com/hartkopp/can-isotp-modules.
    
    The build and repository cleanup provided by Nathan L. Conrad  was merged from
    https://github.com/downwith/linux-isotp . Thanks Nathan!
    
    Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d99b102
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,21 @@
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.  This program is distributed in the hope that it will be useful, but
+# without any warranty; without even the implied warranty of mechantability or
+# fitness for a particular purpose.  See the GNU General Public License for
+# more details.  You should have received a copy of the GNU General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Nathan L. Conrad <nathan@noreply.alt-teknik.com>
+#
+
+.*.cmd
+*.ko
+*.o
+*.mod.c
+modules.order
+/.tmp_versions/
+/Module.symvers
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..eaee963
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,31 @@
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.  This program is distributed in the hope that it will be useful, but
+# without any warranty; without even the implied warranty of mechantability or
+# fitness for a particular purpose.  See the GNU General Public License for
+# more details.  You should have received a copy of the GNU General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Nathan L. Conrad <nathan@noreply.alt-teknik.com>
+#
+
+ifneq ($(KERNELRELEASE),)
+	obj-y := net/can/
+else
+	KERNELDIR ?= /lib/modules/$(shell uname -r)/build
+	PWD := $(shell pwd)
+modules:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) PROJECT_DIR=$(PWD) modules
+modules_install:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install
+	@depmod
+endif
+.PHONY: clean
+clean:
+	@find -type f '(' -name '.*.cmd' -o -name '*.ko' -o -name '*.o' -o \
+		-name '*.mod.c' -o -name 'modules.order' ')' -delete
+	@rm -rf .tmp_versions
+	@rm -f Module.symvers
diff --git a/README.isotp b/README.isotp
new file mode 100644
index 0000000..31be613
--- /dev/null
+++ b/README.isotp
@@ -0,0 +1,299 @@
+============================================================================
+
+README.isotp
+
+CREDITS
+
+This repository contains a rework to simplify the build of the former ISO-TP
+development repository at https://github.com/hartkopp/can-isotp-modules.
+
+The build and repository cleanup provided by Nathan L. Conrad  was merged from
+https://github.com/downwith/linux-isotp . Thanks Nathan!
+
+DOWNLOAD and BUILD
+
+1. Download repository
+
+      git clone https://github.com/hartkopp/can-isotp.git
+
+2. Build ISO-TP kernel module
+
+   Ensure dependencies are installed.  For Debian (or Ubuntu):
+
+      sudo apt-get install build-essential linux-headers-$(uname -r)
+
+   To build:
+
+      make
+
+   To install (optional):
+
+      sudo make modules_install
+
+
+3. When the PF_CAN core module is loaded ('modprobe can') the ISO-TP module
+   can be loaded into the kernel with
+
+       insmod ./net/can/can-isotp.ko
+
+   When the can-isotp.ko module has been installed into the Linux Kernels
+   modules directory (e.g. with 'make modules_install') the module should
+   load automatically when opening a CAN_ISOTP socket.
+
+----------------------------------------------------------------------------
+
+Readme file for ISO 15765-2 CAN transport protocol for protocol family CAN
+
+* This implementation is already widely used in automotive use-cases, e.g.
+* for UDS based OBD diagnosis. Although some small adaptions may be applied
+* to make it ready for Linux Mainline. Feedback is welcome.
+*
+* Current behaviour:
+*
+* - no ISO-TP specific return values are provided to the userspace
+* - when a transfer (tx) is on the run the next write() blocks until it's done
+* - no support for sending wait frames to the data source in the rx path
+
+
+  1 What is ISO-TP for CAN
+
+  2 Tools and Examples
+    2.1 isotpsend - send PDUs from stdin to CAN
+    2.2 isotprecv - print received PDU on stdout
+    2.3 isotpdump - dump CAN frames with PCI decoding (using CAN_RAW socket)
+    2.4 isotpsniffer - dump reassembled ISO-TP PDUs (using CAN_ISOTP socket)
+    2.5 isotptun - create an IP tunnel over unreliable ISO-TP PDUs
+
+  3 Remarks
+    3.1 tx_queue_len on real CAN busses (!!!)
+    3.2 State of the Socket API & Discussion
+
+1 What is ISO-TP for CAN
+------------------------
+
+  CAN Transport Protocols offer support for segmented Point-to-Point
+  communication between CAN nodes via two defined CAN Identifiers.
+  This protocol driver implements data transfers according ISO 15765-2.
+
+  CAN ISO-TP is an unreliable datagram protocol and is implemented like this.
+  For that reason error indications, like 'dropped PDUs in the receive path due
+  to wrong SequenceNumbers' are intentionally not supported.
+  See discussion in section 3.2
+
+  Code examples of how to use ISO-TP sockets can be found in the source code
+  of the available tools described below. The API is still a RFC and will be
+  described in detail later, when it's finalized.
+
+
+2 Tools and Examples
+--------------------
+
+  The source code of these tools can be found in the BerliOS SVN repository
+  http://developer.berlios.de/svn/?group_id=6475 in trunk/can-utils
+
+  For the examples below we assume a test setup with two hosts:
+
+         _______          _______ 
+        |       |        |       |
+        | Host1 |        | Host2 |
+        |       |        |       |
+        | can1  |        | can2  |
+        |_______|        |_______|
+            |                |
+     |------------------------------| CAN bus
+
+
+  2.1 isotpsend - send PDUs from stdin to CAN
+
+  isotpsend gives this help when invoked without any parameters:
+
+  Usage: isotpsend [options] <CAN interface>
+  Options: -s <can_id>  (source can_id. Use 8 digits for extended IDs)
+           -d <can_id>  (destination can_id. Use 8 digits for extended IDs)
+           -x <addr>    (extended addressing mode. Use 'any' for all addresses)
+           -p <byte>    (set and enable padding byte)
+           -P <mode>    (check padding in FC. (l)ength (c)ontent (a)ll)
+           -t <time ns> (transmit time in nanosecs)
+
+  CAN IDs and addresses are given and expected in hexadecimal values.
+  The pdu data is expected on STDIN in space separated ASCII hex values.
+  
+  Example (send ISOTP PDU from Host2 to Host1):
+  echo 11 22 33 44 55 66 DE AD BE EF | isotpsend -s 321 -d 123 can2
+
+
+  2.2 isotprecv - print received PDU on stdout
+
+  isotpsend gives this help when invoked without any parameters:
+
+  Usage: isotprecv [options] <CAN interface>
+  Options: -s <can_id>  (source can_id. Use 8 digits for extended IDs)
+           -d <can_id>  (destination can_id. Use 8 digits for extended IDs)
+           -x <addr>    (extended addressing mode.)
+           -p <byte>    (set and enable padding byte)
+           -P <mode>    (check padding in SF/CF. (l)ength (c)ontent (a)ll)
+           -b <bs>      (blocksize. 0 = off)
+           -m <val>     (STmin in ms/ns. See spec.)
+           -w <num>     (max. wait frame transmissions.)
+           -l           (loop: do not exit after pdu receiption.)
+
+  CAN IDs and addresses are given and expected in hexadecimal values.
+  The pdu data is written on STDOUT in space separated ASCII hex values.
+
+  Example (receive ISOTP PDU from Host2 on Host1):
+  isotprecv -s 123 -d 321 -l can1
+
+  In this example '-l' is set which causes isotprecv to continue listening on
+  the given connection after printing a received PDU.
+
+
+  2.3 isotpdump - dump CAN frames with PCI decoding (using CAN_RAW socket)
+
+  isotpdump gives this help when invoked without any parameters:
+
+  Usage: isotpdump [options] <CAN interface>
+  Options: -s <can_id> (source can_id. Use 8 digits for extended IDs)
+           -d <can_id> (destination can_id. Use 8 digits for extended IDs)
+           -x <addr>   (extended addressing mode. Use 'any' for all addresses)
+           -c          (color mode)
+           -a          (print data also in ASCII-chars)
+           -t <type>   (timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date)
+
+  CAN IDs and addresses are given and expected in hexadecimal values.
+
+  Example (dump CAN Frames on Host1):
+  isotpdump -s 123 -d 321 -c -ta can1
+
+
+  2.4 isotpsniffer - dump reassembled ISO-TP PDUs (using CAN_ISOTP socket)
+
+  The difference to isotpdump is, that isotpsniffer opens two CAN_ISOTP
+  sockets and sets the CAN_ISOTP_LISTEN_MODE flag on both of these sockets.
+  This causes the ISO-TP protocol driver to reassemble the received data but
+  not send and flow control frames on the CAN bus.
+
+  isotpsniffer gives this help when invoked without any parameters:
+
+  Usage: isotpsniffer [options] <CAN interface>
+  Options: -s <can_id> (source can_id. Use 8 digits for extended IDs)
+           -d <can_id> (destination can_id. Use 8 digits for extended IDs)
+           -x <addr>   (extended addressing mode.)
+           -c          (color mode)
+           -t <type>   (timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date)
+           -f <format> (1 = HEX, 2 = ASCII, 3 = HEX & ASCII - default: 3)
+           -h <len>    (head: print only first <len> bytes)
+
+  CAN IDs and addresses are given and expected in hexadecimal values.
+
+  Example (dump reassembled ISO-TP PDUs on Host1):
+  isotpsniffer -s 123 -d 321 -c -ta can1
+
+
+  2.5 isotptun - create an IP tunnel over unreliable ISO-TP PDUs
+
+  The ISO-TP provides an unreliable datagram protocol with PDU sizes up to
+  4095 bytes. Having Linux tunnel driver in mind creating an IP over ISO-TP
+  tunnel became obvious - so here it is ;-)
+
+  From linux/Documentation/networking/tuntap.txt:
+  TUN/TAP provides packet reception and transmission for user space programs. 
+  It can be seen as a simple Point-to-Point or Ethernet device, which,
+  instead of receiving packets from physical media, receives them from 
+  user space program and instead of sending packets via physical media 
+  writes them to the user space program. 
+
+  isotptun gives this help when invoked without any parameters:
+
+  Usage: isotptun [options] <CAN interface>
+
+  This program creates a Linux tunnel netdevice 'ctunX' and transfers the
+  ethernet frames inside ISO15765-2 (unreliable) datagrams on CAN.
+
+  Options: -s <can_id>  (source can_id. Use 8 digits for extended IDs)
+           -d <can_id>  (destination can_id. Use 8 digits for extended IDs)
+           -x <addr>    (extended addressing mode.)
+           -p <byte>    (padding byte rx path)
+           -q <byte>    (padding byte tx path)
+           -P <mode>    (check padding. (l)ength (c)ontent (a)ll)
+           -t <time ns> (transmit time in nanosecs)
+           -b <bs>      (blocksize. 0 = off)
+           -m <val>     (STmin in ms/ns. See spec.)
+           -w <num>     (max. wait frame transmissions.)
+           -h           (half duplex mode.)
+           -v           (verbose mode. Print symbols for tunneled msgs.)
+
+  CAN IDs and addresses are given and expected in hexadecimal values.
+  Use e.g. 'ifconfig ctun0 123.123.123.1 pointopoint 123.123.123.2 up'
+  to create a point-to-point IP connection on CAN.
+
+  Example:
+
+  on Host1 run as root:
+  isotptun -s 123 -d 321 -v can1 (this blocks, so use a separate terminal)
+
+  ifconfig ctun0 123.123.123.1 pointopoint 123.123.123.2 up
+
+  on Host2 run as root:
+  isotptun -s 321 -d 123 -v can2 (this blocks, so use a separate terminal)
+
+  ifconfig ctun0 123.123.123.2 pointopoint 123.123.123.1 up
+
+  Have fun (like in early modem dialup days):
+  ping 123.123.123.1
+  ssh user@123.123.123.1
+  scp user@123.123.123.1:myfile.tar.gz .
+
+  scp get's about 27kByte/s over a 500kbit/s CAN interface.
+
+
+3 Remarks
+---------
+
+  3.1 tx_queue_len on real CAN busses (!!!)
+
+  The blocksize (BS) splits the CAN frame stream into chunks that need to be
+  acknowledged on the receiver side with a flow control frame. In the case
+  the blocksize is set to zero the protocol does not wait for flow control
+  frames and sends all the CAN frames for the ISO-TP PDU in one burst.
+
+  In the case of a 4095 bytes PDU the protocol driver must create 586(!)
+  CAN frames, that are pushed into the CAN network device. This is no problem
+  with virtual CAN devices (vcan) but for real CAN devices with real bus
+  timings. Even though the frame_txtime (N_As/N_Ar) can be set in the ISO-TP
+  socket options, it is recommended to have an appropriate tx queue available
+  in the CAN driver, e.g.:
+
+    echo 4000 > /sys/class/net/can0/tx_queue_len
+
+  or with the 'ip' tool from the iproute2 package
+
+    ip link set can0 txqueuelen 4000
+
+  3.2 State of the Socket API for this Linux CAN ISO-TP implementation
+
+  Implementing transport protocol drivers in userspace on top of a CAN_RAW
+  socket is possible but has massive drawbacks for fullfilling timing
+  constrains and multi-user handling. Implementing a CAN transport protocol
+  inside the Kernel brings different requirements, as ...
+
+  - it needs to fit into a standard socket API
+  - datagram sockets should always behave similar (e.g. like UDP/IP)
+  - reduce user interaction to a minimal absolutely required level
+  - reduce user programming interface to a minimal absolutely required level
+
+  In the real world applications using unreliable datagram protocols recognize
+  problems via timeouts. So do ISO-TP applications. So the questions is:
+  What does it help for the application to know, that someone 'dropped a PDU
+  in the receive path due to wrong SequenceNumbers'?
+
+  The application does not know the (so far received) content and therefore
+  gets this completely useless information to do *what* with it?
+
+  From current applications perspective the things that have not been
+  implemented have not been required so far. So this might become the
+  discussion upon this implementation:
+
+  - what is really needed and for what use-case?
+  - how does this fit into standard networking and socket philosophy?
+
+Oliver Hartkopp (2017-04-22)
diff --git a/include/uapi/linux/can/isotp.h b/include/uapi/linux/can/isotp.h
new file mode 100644
index 0000000..c21ad18
--- /dev/null
+++ b/include/uapi/linux/can/isotp.h
@@ -0,0 +1,134 @@
+/*
+ * socketcan/can/isotp.h
+ *
+ * Definitions for isotp CAN sockets
+ *
+ * Author: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
+ * Copyright (c) 2008 Volkswagen Group Electronic Research
+ * All rights reserved.
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#ifndef CAN_ISOTP_H
+#define CAN_ISOTP_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_OPTS		1	/* pass struct can_isotp_options */
+
+#define CAN_ISOTP_RECV_FC	2	/* pass struct can_isotp_fc_options */
+
+/* sockopts to force stmin timer values for protocol regression tests */
+
+#define CAN_ISOTP_TX_STMIN	3	/* pass __u32 value in nano secs    */
+					/* use this time instead of value   */
+					/* provided in FC from the receiver */
+
+#define CAN_ISOTP_RX_STMIN	4	/* pass __u32 value in nano secs   */
+					/* ignore received CF frames which */
+					/* timestamps differ less than val */
+
+#define CAN_ISOTP_LL_OPTS	5	/* 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_MODE	0x001	/* listen only (do not send FC) */
+#define CAN_ISOTP_EXTEND_ADDR	0x002	/* enable extended addressing */
+#define CAN_ISOTP_TX_PADDING	0x004	/* enable CAN frame padding tx path */
+#define CAN_ISOTP_RX_PADDING	0x008	/* enable CAN frame padding rx path */
+#define CAN_ISOTP_CHK_PAD_LEN	0x010	/* check received CAN frame padding */
+#define CAN_ISOTP_CHK_PAD_DATA	0x020	/* check received CAN frame padding */
+#define CAN_ISOTP_HALF_DUPLEX	0x040	/* half duplex error state handling */
+#define CAN_ISOTP_FORCE_TXSTMIN	0x080	/* ignore stmin from received FC */
+#define CAN_ISOTP_FORCE_RXSTMIN	0x100	/* ignore CFs depending on rx stmin */
+#define CAN_ISOTP_RX_EXT_ADDR	0x200	/* different rx extended addressing */
+
+
+/* default values */
+
+#define CAN_ISOTP_DEFAULT_FLAGS		0
+#define CAN_ISOTP_DEFAULT_EXT_ADDRESS	0x00
+#define CAN_ISOTP_DEFAULT_PAD_CONTENT	0xCC /* prevent bit-stuffing */
+#define CAN_ISOTP_DEFAULT_FRAME_TXTIME	0
+#define CAN_ISOTP_DEFAULT_RECV_BS	0
+#define CAN_ISOTP_DEFAULT_RECV_STMIN	0x00
+#define CAN_ISOTP_DEFAULT_RECV_WFTMAX	0
+
+#define CAN_ISOTP_DEFAULT_LL_MTU	CAN_MTU
+#define CAN_ISOTP_DEFAULT_LL_TX_DL	CAN_MAX_DLEN
+#define CAN_ISOTP_DEFAULT_LL_TX_FLAGS	0
+
+/*
+ * 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
diff --git a/net/can/Makefile b/net/can/Makefile
new file mode 100644
index 0000000..fe2b7aa
--- /dev/null
+++ b/net/can/Makefile
@@ -0,0 +1,25 @@
+#
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.  This program is distributed in the hope that it will be useful, but
+# without any warranty; without even the implied warranty of mechantability or
+# fitness for a particular purpose.  See the GNU General Public License for
+# more details.  You should have received a copy of the GNU General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Nathan L. Conrad <nathan@noreply.alt-teknik.com>
+#
+
+ifneq ($(KERNELRELEASE),)
+	ccflags-y += -I$(PROJECT_DIR)/include/uapi
+	obj-m := can-isotp.o
+	can-isotp-objs := isotp.o
+else
+	KERNELDIR ?= /lib/modules/$(shell uname -r)/build
+modules:
+	$(MAKE) -C $(KERNELDIR) M=$(shell pwd) modules
+modules_install:
+	$(MAKE) -C $(KERNELDIR) M=$(shell pwd) modules_install
+endif
diff --git a/net/can/isotp.c b/net/can/isotp.c
new file mode 100644
index 0000000..6a285c1
--- /dev/null
+++ b/net/can/isotp.c
@@ -0,0 +1,1462 @@
+/*
+ * isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
+ *
+ * WARNING: This is ALPHA code for discussions and first tests that should
+ *          not be used in production environments.
+ *
+ * In the discussion the Socket-API to the userspace or the ISO-TP socket
+ * options or the return values we may change! Current behaviour:
+ *
+ * - no ISO-TP specific return values are provided to the userspace
+ * - when a transfer (tx) is on the run the next write() blocks until it's done
+ * - no support for sending wait frames to the data source in the rx path
+ *
+ * Copyright (c) 2008 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.
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/hrtimer.h>
+#include <linux/wait.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/core.h>
+#include <linux/can/isotp.h>
+#include <net/sock.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
+#include <net/net_namespace.h>
+#endif
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
+#include "compat.h"
+#endif
+
+#define CAN_ISOTP_VERSION "20161031"
+static __initdata const char banner[] =
+	KERN_INFO "can: isotp protocol (rev " CAN_ISOTP_VERSION " alpha)\n";
+
+MODULE_DESCRIPTION("PF_CAN isotp 15765-2 protocol");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
+MODULE_ALIAS("can-proto-6");
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
+#error This modules needs hrtimers (available since Kernel 2.6.22)
+#endif
+
+#define DBG(fmt, args...) (printk( KERN_DEBUG "can-isotp: %s: " fmt, \
+				   __func__, ##args))
+#undef DBG
+#define DBG(fmt, args...)
+
+#define SINGLE_MASK(id) ((id & CAN_EFF_FLAG) ? \
+			 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
+			 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
+
+/*
+  ISO 15765-2:2015 supports more than 4095 byte per ISO PDU as the FF_DL can
+  take full 32 bit values (4 Gbyte). We would need some good concept to handle
+  this between user space and kernel space. For now increase the static buffer
+  to something about 8 kbyte to be able to test this new functionality.
+*/
+#define MAX_MSG_LENGTH 8200
+
+/* N_PCI type values in bits 7-4 of N_PCI bytes */
+#define N_PCI_SF	0x00 /* single frame */
+#define N_PCI_FF	0x10 /* first frame */
+#define N_PCI_CF	0x20 /* consecutive frame */
+#define N_PCI_FC	0x30 /* flow control */
+
+#define N_PCI_SZ 1	/* size of the PCI byte #1 */
+#define SF_PCI_SZ4 1	/* size of SingleFrame PCI including 4 bit SF_DL */
+#define SF_PCI_SZ8 2	/* size of SingleFrame PCI including 8 bit SF_DL */
+#define FF_PCI_SZ12 2	/* size of FirstFrame PCI including 12 bit FF_DL */
+#define FF_PCI_SZ32 6	/* size of FirstFrame PCI including 32 bit FF_DL */
+#define FC_CONTENT_SZ 3	/* flow control content size in byte (FS/BS/STmin) */
+
+#define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
+
+/* Flow Status given in FC frame */
+#define ISOTP_FC_CTS	0	/* clear to send */
+#define ISOTP_FC_WT	1	/* wait */
+#define ISOTP_FC_OVFLW	2	/* overflow */
+
+enum {
+	ISOTP_IDLE = 0,
+	ISOTP_WAIT_FIRST_FC,
+	ISOTP_WAIT_FC,
+	ISOTP_WAIT_DATA,
+	ISOTP_SENDING
+};
+
+struct tpcon {
+	int idx;
+	int len;
+	u8  state;
+	u8  bs;
+	u8  sn;
+	u8  ll_dl;
+	u8  buf[MAX_MSG_LENGTH+1];
+};
+
+struct isotp_sock {
+	struct sock sk;
+	int bound;
+	int ifindex;
+	canid_t txid;
+	canid_t rxid;
+	ktime_t tx_gap;
+	ktime_t lastrxcf_tstamp;
+	struct hrtimer rxtimer, txtimer;
+	struct tasklet_struct txtsklet;
+	struct can_isotp_options opt;
+	struct can_isotp_fc_options rxfc, txfc;
+	struct can_isotp_ll_options ll;
+	__u32 force_tx_stmin;
+	__u32 force_rx_stmin;
+	struct tpcon rx, tx;
+	struct notifier_block notifier;
+	wait_queue_head_t wait;
+};
+
+static inline struct isotp_sock *isotp_sk(const struct sock *sk)
+{
+	return (struct isotp_sock *)sk;
+}
+
+static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
+{
+	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+					     rxtimer);
+	if (so->rx.state == ISOTP_WAIT_DATA) {
+		DBG("we did not get new data frames in time.\n");
+
+		/* reset tx state */
+		so->rx.state = ISOTP_IDLE;
+	}
+
+	return HRTIMER_NORESTART;
+}
+
+static void isotp_skb_destructor(struct sk_buff *skb)
+{
+	sock_put(skb->sk);
+}
+
+static inline void isotp_skb_set_owner(struct sk_buff *skb, struct sock *sk)
+{
+	if (sk) {
+		sock_hold(sk);
+		skb->destructor = isotp_skb_destructor;
+		skb->sk = sk;
+	}
+}
+
+static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
+{
+	struct net_device *dev;
+	struct sk_buff *nskb;
+	struct canfd_frame *ncf;
+	struct isotp_sock *so = isotp_sk(sk);
+
+	nskb = alloc_skb(so->ll.mtu, gfp_any());
+	if (!nskb)
+		return 1;
+
+	dev = dev_get_by_index(&init_net, so->ifindex);
+	if (!dev) {
+		kfree_skb(nskb);
+		return 1;
+	}
+	nskb->dev = dev;
+	isotp_skb_set_owner(nskb, sk);
+	ncf = (struct canfd_frame *) nskb->data;
+	skb_put(nskb, so->ll.mtu);
+
+	/* create & send flow control reply */
+	ncf->can_id = so->txid;
+
+	if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
+		memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
+		ncf->len = CAN_MAX_DLEN;
+	} else
+		ncf->len = ae + FC_CONTENT_SZ;
+
+	ncf->data[ae] = N_PCI_FC | flowstatus;
+	ncf->data[ae + 1] = so->rxfc.bs;
+	ncf->data[ae + 2] = so->rxfc.stmin;
+
+	if (ae)
+		ncf->data[0] = so->opt.ext_address;
+
+	if (so->ll.mtu == CANFD_MTU)
+		ncf->flags = so->ll.tx_flags;
+
+	can_send(nskb, 1);
+	dev_put(dev);
+
+	/* reset blocksize counter */
+	so->rx.bs = 0;
+
+	/* reset last CF frame rx timestamp for rx stmin enforcement */
+	so->lastrxcf_tstamp = ktime_set(0,0);
+
+	/* start rx timeout watchdog */
+	hrtimer_start(&so->rxtimer, ktime_set(1,0), HRTIMER_MODE_REL);
+	return 0;
+}
+
+static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
+
+	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
+
+	memset(addr, 0, sizeof(*addr));
+	addr->can_family  = AF_CAN;
+	addr->can_ifindex = skb->dev->ifindex;
+
+	if (sock_queue_rcv_skb(sk, skb) < 0)
+		kfree_skb(skb);
+}
+
+static u8 padlen(u8 datalen)
+{
+	const u8 plen[] = {8,  8,  8,  8,  8,  8,  8,  8,  8,	/* 0 - 8 */
+			   12, 12, 12, 12,			/* 9 - 12 */
+			   16, 16, 16, 16,			/* 13 - 16 */
+			   20, 20, 20, 20,			/* 17 - 20 */
+			   24, 24, 24, 24,			/* 21 - 24 */
+			   32, 32, 32, 32, 32, 32, 32, 32,	/* 25 - 32 */
+			   48, 48, 48, 48, 48, 48, 48, 48,	/* 33 - 40 */
+			   48, 48, 48, 48, 48, 48, 48, 48};	/* 41 - 48 */
+
+	if (datalen > 48)
+		return 64;
+
+	return plen[datalen];
+}
+
+/* check for length optimization and return 1/true when the check fails */
+static int check_optimized(struct canfd_frame *cf, int start_index)
+{
+	/*
+	 * for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
+	 * padding would start at this point. E.g. if the padding would
+	 * start at cf.data[7] cf->len has to be 7 to be optimal.
+	 * Note: The data[] index starts with zero.
+	 */
+	if (cf->len <= CAN_MAX_DLEN)
+		return (cf->len != start_index);
+
+	/*
+	 * This relation is also valid in the non-linear DLC range, where
+	 * we need to take care of the minimal next possible CAN_DL.
+	 * The correct check would be (padlen(cf->len) != padlen(start_index)).
+	 * But as cf->len can only take discrete values from 12, .., 64 at this
+	 * point the padlen(cf->len) is always equal to cf->len.
+	 */
+	return (cf->len != padlen(start_index));
+}
+
+/* check padding and return 1/true when the check fails */
+static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
+		     int start_index, __u8 content)
+{
+	int i;
+
+	/* no RX_PADDING value => check length of optimized frame length */
+	if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
+
+		if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
+			return check_optimized(cf, start_index);
+
+		/* no valid test against empty value => ignore frame */
+		return 1;
+	}
+
+	/* check datalength of correctly padded CAN frame */
+	if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
+	    cf->len != padlen(cf->len))
+			return 1;
+
+	/* check padding content */
+	if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
+		for (i = start_index; i < cf->len; i++)
+			if (cf->data[i] != content)
+				return 1;
+	}
+	return 0;
+}
+
+static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
+{
+	if (so->tx.state != ISOTP_WAIT_FC &&
+	    so->tx.state != ISOTP_WAIT_FIRST_FC)
+		return 0;
+
+	hrtimer_cancel(&so->txtimer);
+
+	if ((cf->len < ae + FC_CONTENT_SZ) ||
+	    ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+	     check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
+		so->tx.state = ISOTP_IDLE;
+		wake_up_interruptible(&so->wait);
+		return 1;
+	}
+
+	/* get communication parameters only from the first FC frame */
+	if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
+
+		so->txfc.bs = cf->data[ae + 1];
+		so->txfc.stmin = cf->data[ae + 2];
+
+		/* fix wrong STmin values according spec */
+		if ((so->txfc.stmin > 0x7F) &&
+		    ((so->txfc.stmin < 0xF1) || (so->txfc.stmin > 0xF9)))
+			so->txfc.stmin = 0x7F;
+
+		so->tx_gap = ktime_set(0,0);
+		/* add transmission time for CAN frame N_As */
+		so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
+		/* add waiting time for consecutive frames N_Cs */
+		if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
+			so->tx_gap = ktime_add_ns(so->tx_gap,
+						  so->force_tx_stmin);
+		else if (so->txfc.stmin < 0x80)
+			so->tx_gap = ktime_add_ns(so->tx_gap,
+						  so->txfc.stmin * 1000000);
+		else
+			so->tx_gap = ktime_add_ns(so->tx_gap,
+						  (so->txfc.stmin - 0xF0)
+						  * 100000);
+		so->tx.state = ISOTP_WAIT_FC;
+	}
+
+	DBG("FC frame: FS %d, BS %d, STmin 0x%02X, tx_gap %lld\n",
+	    cf->data[ae] & 0x0F & 0x0F, so->txfc.bs, so->txfc.stmin,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)
+	    (long long)so->tx_gap);
+#else
+	    (long long)so->tx_gap.tv64);
+#endif
+
+	switch (cf->data[ae] & 0x0F) {
+
+	case ISOTP_FC_CTS:
+		so->tx.bs = 0;
+		so->tx.state = ISOTP_SENDING;
+		DBG("starting txtimer for sending\n");
+		/* start cyclic timer for sending CF frame */
+		hrtimer_start(&so->txtimer, so->tx_gap,
+			      HRTIMER_MODE_REL);
+		break;
+
+	case ISOTP_FC_WT:
+		DBG("starting waiting for next FC\n");
+		/* start timer to wait for next FC frame */
+		hrtimer_start(&so->txtimer, ktime_set(1,0),
+			      HRTIMER_MODE_REL);
+		break;
+
+	case ISOTP_FC_OVFLW:
+		DBG("overflow in receiver side\n");
+
+	default:
+		/* stop this tx job. TODO: error reporting? */
+		so->tx.state = ISOTP_IDLE;
+		wake_up_interruptible(&so->wait);
+	}
+	return 0;
+}
+
+static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
+			struct sk_buff *skb, int len)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+	struct sk_buff *nskb;
+
+	hrtimer_cancel(&so->rxtimer);
+	so->rx.state = ISOTP_IDLE;
+
+	if (!len || len > cf->len - pcilen)
+		return 1;
+
+	if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+	    check_pad(so, cf, pcilen + len, so->opt.rxpad_content))
+		return 1;
+
+	nskb = alloc_skb(len, gfp_any());
+	if (!nskb)
+		return 1;
+
+	memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
+
+	nskb->tstamp = skb->tstamp;
+	nskb->dev = skb->dev;
+	isotp_rcv_skb(nskb, sk);
+	return 0;
+}
+
+static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+	int i;
+	int off;
+	int ff_pci_sz;
+
+	hrtimer_cancel(&so->rxtimer);
+	so->rx.state = ISOTP_IDLE;
+
+	/* get the used sender LL_DL from the (first) CAN frame data length */
+	so->rx.ll_dl = padlen(cf->len);
+
+	/* the first frame has to use the entire frame up to LL_DL length */
+	if (cf->len != so->rx.ll_dl)
+		return 1;
+
+	/* get the FF_DL */
+	so->rx.len = (cf->data[ae] & 0x0F) << 8;
+	so->rx.len += cf->data[ae + 1];
+
+	/* Check for FF_DL escape sequence supporting 32 bit PDU length */
+	if (so->rx.len)
+		ff_pci_sz = FF_PCI_SZ12;
+	else {
+		/* FF_DL = 0 => get real length from next 4 bytes */
+		so->rx.len = cf->data[ae + 2] << 24;
+		so->rx.len += cf->data[ae + 3] << 16;
+		so->rx.len += cf->data[ae + 4] << 8;
+		so->rx.len += cf->data[ae + 5];
+		ff_pci_sz = FF_PCI_SZ32;
+	}
+
+	/* take care of a potential SF_DL ESC offset for TX_DL > 8 */
+	off = (so->rx.ll_dl > CAN_MAX_DLEN)? 1:0;
+
+	if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
+		return 1;
+
+	if (so->rx.len > MAX_MSG_LENGTH) {
+		/* send FC frame with overflow status */
+		isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
+		return 1;
+	}
+
+	/* copy the first received data bytes */
+	so->rx.idx = 0;
+	for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
+		so->rx.buf[so->rx.idx++] = cf->data[i];
+
+	/* initial setup for this pdu receiption */
+	so->rx.sn = 1;
+	so->rx.state = ISOTP_WAIT_DATA;
+
+	/* no creation of flow control frames */
+	if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
+		return 0;
+
+	/* send our first FC frame */
+	isotp_send_fc(sk, ae, ISOTP_FC_CTS);
+	return 0;
+}
+
+static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
+			struct sk_buff *skb)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+	struct sk_buff *nskb;
+	int i;
+
+	if (so->rx.state != ISOTP_WAIT_DATA)
+		return 0;
+
+	/* drop if timestamp gap is less than force_rx_stmin nano secs */
+	if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
+
+		if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
+		    so->force_rx_stmin)
+			return 0;
+
+		so->lastrxcf_tstamp = skb->tstamp;
+	}
+
+	hrtimer_cancel(&so->rxtimer);
+
+	/* CFs are never longer than the FF */
+	if (cf->len > so->rx.ll_dl)
+		return 1;
+
+	/* CFs have usually the LL_DL length */
+	if (cf->len < so->rx.ll_dl) {
+		/* this is only allowed for the last CF */
+		if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
+			return 1;
+	}
+
+	if ((cf->data[ae] & 0x0F) != so->rx.sn) {
+		DBG("wrong sn %d. expected %d.\n",
+		    cf->data[ae] & 0x0F, so->rx.sn);
+		/* some error reporting? */
+		so->rx.state = ISOTP_IDLE;
+		return 1;
+	}
+	so->rx.sn++;
+	so->rx.sn %= 16;
+
+	for (i = ae + N_PCI_SZ; i < cf->len; i++) {
+		so->rx.buf[so->rx.idx++] = cf->data[i];
+		if (so->rx.idx >= so->rx.len)
+			break;
+	}
+
+	if (so->rx.idx >= so->rx.len) {
+
+		/* we are done */
+		so->rx.state = ISOTP_IDLE;
+
+		if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+		    check_pad(so, cf, i+1, so->opt.rxpad_content))
+			return 1;
+
+		nskb = alloc_skb(so->rx.len, gfp_any());
+		if (!nskb)
+			return 1;
+
+		memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
+		       so->rx.len);
+
+		nskb->tstamp = skb->tstamp;
+		nskb->dev = skb->dev;
+		isotp_rcv_skb(nskb, sk);
+		return 0;
+	}
+
+	/* no creation of flow control frames */
+	if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
+		return 0;
+
+	/* perform blocksize handling, if enabled */
+	if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
+
+		/* start rx timeout watchdog */
+		hrtimer_start(&so->rxtimer, ktime_set(1,0),
+			      HRTIMER_MODE_REL);
+		return 0;
+	}
+
+	/* we reached the specified blocksize so->rxfc.bs */
+	isotp_send_fc(sk, ae, ISOTP_FC_CTS);
+	return 0;
+}
+
+static void isotp_rcv(struct sk_buff *skb, void *data)
+{
+	struct sock *sk = (struct sock *)data;
+	struct isotp_sock *so = isotp_sk(sk);
+	struct canfd_frame *cf;
+	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR)? 1:0;
+	u8 n_pci_type, sf_dl;
+
+	BUG_ON(skb->len != CAN_MTU && skb->len != CANFD_MTU);
+
+	/*
+	 * Strictly receive only frames with the configured MTU size
+	 * => clear separation of CAN2.0 / CAN FD transport channels
+	 */
+	if (skb->len != so->ll.mtu)
+		return;
+
+	cf = (struct canfd_frame *) skb->data;
+
+	/* if enabled: check receiption of my configured extended address */
+	if (ae && cf->data[0] != so->opt.rx_ext_address)
+		return;
+
+	n_pci_type = cf->data[ae] & 0xF0;
+
+	if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
+		/* check rx/tx path half duplex expectations */
+		if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
+		    (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
+			return;
+	}
+
+	switch (n_pci_type) {
+	case N_PCI_FC:
+		/* tx path: flow control frame containing the FC parameters */
+		isotp_rcv_fc(so, cf, ae);
+		break;
+
+	case N_PCI_SF:
+		/*
+		 * rx path: single frame
+		 *
+		 * As we do not have a rx.ll_dl configuration, we can only test
+		 * if the CAN frames payload length matches the LL_DL == 8
+		 * requirements - no matter if it's CAN 2.0 or CAN FD
+		 */
+
+		/* get the SF_DL from the N_PCI byte */
+		sf_dl = cf->data[ae] & 0x0F;
+
+		if (cf->len <= CAN_MAX_DLEN)
+			isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
+		else if (skb->len == CANFD_MTU) {
+			/*
+			 * We have a CAN FD frame and CAN_DL is greater than 8:
+			 * Only frames with the SF_DL == 0 ESC value are valid.
+			 *
+			 * If so take care of the increased SF PCI size
+			 * (SF_PCI_SZ8) to point to the message content behind
+			 * the extended SF PCI info and get the real SF_DL
+			 * length value from the formerly first data byte.
+			 */
+			if (sf_dl == 0)
+				isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
+					     cf->data[SF_PCI_SZ4 + ae]);
+		}
+		break;
+
+	case N_PCI_FF:
+		/* rx path: first frame */
+		isotp_rcv_ff(sk, cf, ae);
+		break;
+
+	case N_PCI_CF:
+		/* rx path: consecutive frame */
+		isotp_rcv_cf(sk, cf, ae, skb);
+		break;
+
+	}
+}
+
+static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
+				 int ae, int off)
+{
+	int pcilen = N_PCI_SZ + ae + off;
+	int space = so->tx.ll_dl - pcilen;
+	int num = min_t(int, so->tx.len - so->tx.idx, space);
+	int i;
+
+	cf->can_id = so->txid;
+	cf->len = num + pcilen;
+
+	if (num < space) {
+		if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
+			/* user requested padding */
+			cf->len = padlen(cf->len);
+			memset(cf->data, so->opt.txpad_content, cf->len);
+		} else if (cf->len > CAN_MAX_DLEN) {
+			/* mandatory padding for CAN FD frames */
+			cf->len = padlen(cf->len);
+			memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
+			       cf->len);
+		}
+	}
+
+	for (i = 0; i < num; i++)
+		cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
+
+	if (ae)
+		cf->data[0] = so->opt.ext_address;
+}
+
+static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
+				int ae)
+{
+	int i;
+	int ff_pci_sz;
+
+	cf->can_id = so->txid;
+	cf->len = so->tx.ll_dl;
+	if (ae)
+		cf->data[0] = so->opt.ext_address;
+
+	/* create N_PCI bytes with 12/32 bit FF_DL data length */
+	if (so->tx.len > 4095) {
+		/* use 32 bit FF_DL notation */
+		cf->data[ae] = N_PCI_FF;
+		cf->data[ae + 1] = 0;
+		cf->data[ae + 2] = (u8) (so->tx.len >> 24) & 0xFFU;
+		cf->data[ae + 3] = (u8) (so->tx.len >> 16) & 0xFFU;
+		cf->data[ae + 4] = (u8) (so->tx.len >> 8) & 0xFFU;
+		cf->data[ae + 5] = (u8) so->tx.len & 0xFFU;
+		ff_pci_sz = FF_PCI_SZ32;
+	} else {
+		/* use 12 bit FF_DL notation */
+		cf->data[ae] = (u8) (so->tx.len>>8) | N_PCI_FF;
+		cf->data[ae + 1] = (u8) so->tx.len & 0xFFU;
+		ff_pci_sz = FF_PCI_SZ12;
+	}
+
+	/* add first data bytes depending on ae */
+	for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
+		cf->data[i] = so->tx.buf[so->tx.idx++];
+
+	so->tx.sn = 1;
+	so->tx.state = ISOTP_WAIT_FIRST_FC;
+}
+
+static void isotp_tx_timer_tsklet(unsigned long data)
+{
+	struct isotp_sock *so = (struct isotp_sock *)data;
+	struct sock *sk = &so->sk;
+	struct sk_buff *skb;
+	struct net_device *dev;
+	struct canfd_frame *cf;
+	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR)? 1:0;
+
+	switch (so->tx.state) {
+
+	case ISOTP_WAIT_FC:
+	case ISOTP_WAIT_FIRST_FC:
+
+		/* we did not get any flow control frame in time */
+
+		DBG("we did not get FC frame in time.\n");
+
+		/* reset tx state */
+		so->tx.state = ISOTP_IDLE;
+		wake_up_interruptible(&so->wait);
+		break;
+
+	case ISOTP_SENDING:
+
+		/* push out the next segmented pdu */
+
+		DBG("next pdu to send.\n");
+
+		dev = dev_get_by_index(&init_net, so->ifindex);
+		if (!dev)
+			break;
+
+isotp_tx_burst:
+		skb = alloc_skb(so->ll.mtu, gfp_any());
+		if (!skb) {
+			dev_put(dev);
+			break;
+		}
+
+		cf = (struct canfd_frame *)skb->data;
+		skb_put(skb, so->ll.mtu);
+
+		/* create consecutive frame */
+		isotp_fill_dataframe(cf, so, ae, 0);
+
+		/* place consecutive frame N_PCI in appropriate index */
+		cf->data[ae] = N_PCI_CF | so->tx.sn++;
+		so->tx.sn %= 16;
+		so->tx.bs++;
+
+		if (so->ll.mtu == CANFD_MTU)
+			cf->flags = so->ll.tx_flags;
+
+		skb->dev = dev;
+		isotp_skb_set_owner(skb, sk);
+		can_send(skb, 1);
+
+		if (so->tx.idx >= so->tx.len) {
+			/* we are done */
+			DBG("we are done\n");
+			so->tx.state = ISOTP_IDLE;
+			dev_put(dev);
+			wake_up_interruptible(&so->wait);
+			break;
+		}
+
+		if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
+			/* stop and wait for FC */
+			DBG("BS stop and wait for FC\n");
+			so->tx.state = ISOTP_WAIT_FC;
+			dev_put(dev);
+			hrtimer_start(&so->txtimer,
+				      ktime_add(ktime_get(), ktime_set(1,0)),
+				      HRTIMER_MODE_ABS);
+			break;
+		}
+
+		/* no gap between data frames needed => use burst mode */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)
+		if (!so->tx_gap)
+			goto isotp_tx_burst;
+#else
+		if (!so->tx_gap.tv64)
+			goto isotp_tx_burst;
+#endif
+
+		/* start timer to send next data frame with correct delay */
+		dev_put(dev);
+		hrtimer_start(&so->txtimer,
+			      ktime_add(ktime_get(), so->tx_gap),
+			      HRTIMER_MODE_ABS);
+		break;
+
+	default:
+		BUG_ON(1);
+	}
+}
+
+static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
+{
+	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+					     txtimer);
+	tasklet_schedule(&so->txtsklet);
+
+	return HRTIMER_NORESTART;
+}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,1,0)
+static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+#else
+static int isotp_sendmsg(struct kiocb *iocb, struct socket *sock,
+		       struct msghdr *msg, size_t size)
+#endif
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	struct sk_buff *skb;
+	struct net_device *dev;
+	struct canfd_frame *cf;
+	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR)? 1:0;
+	int off;
+	int err;
+
+	if (!so->bound)
+		return -EADDRNOTAVAIL;
+
+	/* we do not support multiple buffers - for now */
+	if (so->tx.state != ISOTP_IDLE) {
+		if (msg->msg_flags & MSG_DONTWAIT)
+			return -EAGAIN;
+
+		/* wait for complete transmission of current pdu */
+		wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+	}
+
+	if (!size || size > MAX_MSG_LENGTH)
+		return -EINVAL;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,0)
+	err = memcpy_from_msg(so->tx.buf, msg, size);
+#else
+	err = memcpy_fromiovec(so->tx.buf, msg->msg_iov, size);
+#endif
+	if (err < 0)
+		return err;
+
+	dev = dev_get_by_index(&init_net, so->ifindex);
+	if (!dev)
+		return -ENXIO;
+
+	skb = sock_alloc_send_skb(sk, so->ll.mtu,
+				  msg->msg_flags & MSG_DONTWAIT, &err);
+	if (!skb) {
+		dev_put(dev);
+		return err;
+	}
+
+	so->tx.state = ISOTP_SENDING;
+	so->tx.len = size;
+	so->tx.idx = 0;
+
+	cf = (struct canfd_frame *)skb->data;
+	skb_put(skb, so->ll.mtu);
+
+	/* take care of a potential SF_DL ESC offset for TX_DL > 8 */
+	off = (so->tx.ll_dl > CAN_MAX_DLEN)? 1:0;
+
+	/* check for single frame transmission depending on TX_DL */
+	if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
+
+		/*
+		 * The message size generally fits into a SingleFrame - good.
+		 *
+		 * SF_DL ESC offset optimization:
+		 *
+		 * When TX_DL is greater 8 but the message would still fit
+		 * into a 8 byte CAN frame, we can omit the offset.
+		 * This prevents a protocol caused length extension from
+		 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
+		 */
+		if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
+			off = 0;
+
+		isotp_fill_dataframe(cf, so, ae, off);
+
+		/* place single frame N_PCI w/o length in appropriate index */
+		cf->data[ae] = N_PCI_SF;
+
+		/* place SF_DL size value depending on the SF_DL ESC offset */
+		if (off)
+			cf->data[SF_PCI_SZ4 + ae] = size;
+		else
+			cf->data[ae] |= size;
+
+		so->tx.state = ISOTP_IDLE;
+		wake_up_interruptible(&so->wait);
+	} else {
+		/* send first frame and wait for FC */
+
+		isotp_create_fframe(cf, so, ae);
+
+		DBG("starting txtimer for fc\n");
+		/* start timeout for FC */
+		hrtimer_start(&so->txtimer, ktime_set(1,0), HRTIMER_MODE_REL);
+	}
+
+	/* send the first or only CAN frame */
+	if (so->ll.mtu == CANFD_MTU)
+		cf->flags = so->ll.tx_flags;
+
+	skb->dev = dev;
+	skb->sk  = sk;
+	err = can_send(skb, 1);
+	dev_put(dev);
+	if (err)
+		return err;
+
+	return size;
+}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,1,0)
+static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+			 int flags)
+#else
+static int isotp_recvmsg(struct kiocb *iocb, struct socket *sock,
+			 struct msghdr *msg, size_t size, int flags)
+#endif
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	int err = 0;
+	int noblock;
+
+	noblock =  flags & MSG_DONTWAIT;
+	flags   &= ~MSG_DONTWAIT;
+
+	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	if (!skb)
+		return err;
+
+	if (size < skb->len)
+		msg->msg_flags |= MSG_TRUNC;
+	else
+		size = skb->len;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,0)
+	err = memcpy_to_msg(msg, skb->data, size);
+#else
+	err = memcpy_toiovec(msg->msg_iov, skb->data, size);
+#endif
+	if (err < 0) {
+		skb_free_datagram(sk, skb);
+		return err;
+	}
+
+	sock_recv_timestamp(msg, sk, skb);
+
+	if (msg->msg_name) {
+		msg->msg_namelen = sizeof(struct sockaddr_can);
+		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+	}
+
+	skb_free_datagram(sk, skb);
+
+	return size;
+}
+
+static int isotp_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so;
+
+	if (!sk)
+		return 0;
+
+	so = isotp_sk(sk);
+
+	/* wait for complete transmission of current pdu */
+	wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+
+	unregister_netdevice_notifier(&so->notifier);
+
+	lock_sock(sk);
+
+	hrtimer_cancel(&so->txtimer);
+	hrtimer_cancel(&so->rxtimer);
+	tasklet_kill(&so->txtsklet);
+
+	/* remove current filters & unregister */
+	if (so->bound) {
+		if (so->ifindex) {
+			struct net_device *dev;
+
+			dev = dev_get_by_index(&init_net, so->ifindex);
+			if (dev) {
+				can_rx_unregister(dev, so->rxid,
+						  SINGLE_MASK(so->rxid),
+						  isotp_rcv, sk);
+				dev_put(dev);
+			}
+		}
+	}
+
+	so->ifindex = 0;
+	so->bound   = 0;
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	release_sock(sk);
+	sock_put(sk);
+
+	return 0;
+}
+
+static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	int ifindex;
+	struct net_device *dev;
+	int err = 0;
+	int notify_enetdown = 0;
+
+	if (len < sizeof(*addr))
+		return -EINVAL;
+
+	if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)
+		return -EADDRNOTAVAIL;
+
+	if ((addr->can_addr.tp.rx_id | addr->can_addr.tp.tx_id) &
+	    (CAN_ERR_FLAG | CAN_RTR_FLAG))
+		return -EADDRNOTAVAIL;
+
+	if (!addr->can_ifindex)
+		return -ENODEV;
+
+	lock_sock(sk);
+
+	if (so->bound && addr->can_ifindex == so->ifindex &&
+	    addr->can_addr.tp.rx_id == so->rxid &&
+	    addr->can_addr.tp.tx_id == so->txid)
+		goto out;
+
+	dev = dev_get_by_index(&init_net, addr->can_ifindex);
+	if (!dev) {
+		err = -ENODEV;
+		goto out;
+	}
+	if (dev->type != ARPHRD_CAN) {
+		dev_put(dev);
+		err = -ENODEV;
+		goto out;
+	}
+	if (dev->mtu < so->ll.mtu) {
+		dev_put(dev);
+		err = -EINVAL;
+		goto out;
+	}
+	if (!(dev->flags & IFF_UP))
+		notify_enetdown = 1;
+
+	ifindex = dev->ifindex;
+
+	can_rx_register(dev, addr->can_addr.tp.rx_id,
+			SINGLE_MASK(addr->can_addr.tp.rx_id), isotp_rcv, sk,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,9,11)
+			"isotp", sk);
+#else
+			"isotp");
+#endif
+	dev_put(dev);
+
+	if (so->bound) {
+		/* unregister old filter */
+		if (so->ifindex) {
+			dev = dev_get_by_index(&init_net, so->ifindex);
+			if (dev) {
+				can_rx_unregister(dev, so->rxid,
+						  SINGLE_MASK(so->rxid),
+						  isotp_rcv, sk);
+				dev_put(dev);
+			}
+		}
+	}
+
+	/* switch to new settings */
+	so->ifindex = ifindex;
+	so->rxid = addr->can_addr.tp.rx_id;
+	so->txid = addr->can_addr.tp.tx_id;
+	so->bound = 1;
+
+out:
+	release_sock(sk);
+
+	if (notify_enetdown) {
+		sk->sk_err = ENETDOWN;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_error_report(sk);
+	}
+
+	return err;
+}
+
+static int isotp_getname(struct socket *sock, struct sockaddr *uaddr,
+		       int *len, int peer)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+
+	if (peer)
+		return -EOPNOTSUPP;
+
+	addr->can_family  = AF_CAN;
+	addr->can_ifindex = so->ifindex;
+
+	*len = sizeof(*addr);
+
+	return 0;
+}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
+static int isotp_setsockopt(struct socket *sock, int level, int optname,
+			    char __user *optval, unsigned int optlen)
+#else
+static int isotp_setsockopt(struct socket *sock, int level, int optname,
+			    char __user *optval, int optlen)
+#endif
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	int ret = 0;
+
+	if (level != SOL_CAN_ISOTP)
+		return -EINVAL;
+	if (optlen < 0)
+		return -EINVAL;
+
+	switch (optname) {
+
+	case CAN_ISOTP_OPTS:
+		if (optlen != sizeof(struct can_isotp_options))
+			return -EINVAL;
+
+		if (copy_from_user(&so->opt, optval, optlen))
+			return -EFAULT;
+
+		/* no separate rx_ext_address is given => use ext_address */
+		if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
+			so->opt.rx_ext_address = so->opt.ext_address;
+		break;
+
+	case CAN_ISOTP_RECV_FC:
+		if (optlen != sizeof(struct can_isotp_fc_options))
+			return -EINVAL;
+
+		if (copy_from_user(&so->rxfc, optval, optlen))
+			return -EFAULT;
+		break;
+
+	case CAN_ISOTP_TX_STMIN:
+		if (optlen != sizeof(__u32))
+			return -EINVAL;
+
+		if (copy_from_user(&so->force_tx_stmin, optval, optlen))
+			return -EFAULT;
+		break;
+
+	case CAN_ISOTP_RX_STMIN:
+		if (optlen != sizeof(__u32))
+			return -EINVAL;
+
+		if (copy_from_user(&so->force_rx_stmin, optval, optlen))
+			return -EFAULT;
+		break;
+
+	case CAN_ISOTP_LL_OPTS:
+		if (optlen != sizeof(struct can_isotp_ll_options))
+			return -EINVAL;
+		else {
+			struct can_isotp_ll_options ll;
+
+			if (copy_from_user(&ll, optval, optlen))
+				return -EFAULT;
+
+			/* check for correct ISO 11898-1 DLC data lentgh */
+			if (ll.tx_dl != padlen(ll.tx_dl))
+				return -EINVAL;
+
+			if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
+				return -EINVAL;
+
+			if (ll.mtu == CAN_MTU && ll.tx_dl > CAN_MAX_DLEN)
+				return -EINVAL;
+
+			memcpy(&so->ll, &ll, sizeof(ll));
+
+			/* set ll_dl for tx path to similar place as for rx */
+			so->tx.ll_dl = ll.tx_dl;
+		}
+		break;
+
+	default:
+		ret = -ENOPROTOOPT;
+	}
+
+	return ret;
+}
+
+static int isotp_getsockopt(struct socket *sock, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	int len;
+	void *val;
+
+	if (level != SOL_CAN_ISOTP)
+		return -EINVAL;
+	if (get_user(len, optlen))
+		return -EFAULT;
+	if (len < 0)
+		return -EINVAL;
+
+	switch (optname) {
+
+	case CAN_ISOTP_OPTS:
+		len = min_t(int, len, sizeof(struct can_isotp_options));
+		val = &so->opt;
+		break;
+
+	case CAN_ISOTP_RECV_FC:
+		len = min_t(int, len, sizeof(struct can_isotp_fc_options));
+		val = &so->rxfc;
+		break;
+
+	case CAN_ISOTP_TX_STMIN:
+		len = min_t(int, len, sizeof(__u32));
+		val = &so->force_tx_stmin;
+		break;
+
+	case CAN_ISOTP_RX_STMIN:
+		len = min_t(int, len, sizeof(__u32));
+		val = &so->force_rx_stmin;
+		break;
+
+	case CAN_ISOTP_LL_OPTS:
+		len = min_t(int, len, sizeof(struct can_isotp_ll_options));
+		val = &so->ll;
+		break;
+
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	if (put_user(len, optlen))
+		return -EFAULT;
+	if (copy_to_user(optval, val, len))
+		return -EFAULT;
+	return 0;
+}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,11,0)
+static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
+			  void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+#else
+static int isotp_notifier(struct notifier_block *nb,
+			unsigned long msg, void *data)
+{
+	struct net_device *dev = (struct net_device *)data;
+#endif
+	struct isotp_sock *so = container_of(nb, struct isotp_sock, notifier);
+	struct sock *sk = &so->sk;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
+	if (dev_net(dev) != &init_net)
+		return NOTIFY_DONE;
+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24)
+	if (dev->nd_net != &init_net)
+		return NOTIFY_DONE;
+#endif
+
+	if (dev->type != ARPHRD_CAN)
+		return NOTIFY_DONE;
+
+	if (so->ifindex != dev->ifindex)
+		return NOTIFY_DONE;
+
+	switch (msg) {
+
+	case NETDEV_UNREGISTER:
+		lock_sock(sk);
+		/* remove current filters & unregister */
+		if (so->bound)
+			can_rx_unregister(dev, so->rxid, SINGLE_MASK(so->rxid),
+					  isotp_rcv, sk);
+
+		so->ifindex = 0;
+		so->bound   = 0;
+		release_sock(sk);
+
+		sk->sk_err = ENODEV;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_error_report(sk);
+		break;
+
+	case NETDEV_DOWN:
+		sk->sk_err = ENETDOWN;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_error_report(sk);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int isotp_init(struct sock *sk)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+
+	so->ifindex = 0;
+	so->bound   = 0;
+
+	so->opt.flags		= CAN_ISOTP_DEFAULT_FLAGS;
+	so->opt.ext_address	= CAN_ISOTP_DEFAULT_EXT_ADDRESS;
+	so->opt.rx_ext_address	= CAN_ISOTP_DEFAULT_EXT_ADDRESS;
+	so->opt.rxpad_content	= CAN_ISOTP_DEFAULT_PAD_CONTENT;
+	so->opt.txpad_content	= CAN_ISOTP_DEFAULT_PAD_CONTENT;
+	so->opt.frame_txtime	= CAN_ISOTP_DEFAULT_FRAME_TXTIME;
+	so->rxfc.bs		= CAN_ISOTP_DEFAULT_RECV_BS;
+	so->rxfc.stmin		= CAN_ISOTP_DEFAULT_RECV_STMIN;
+	so->rxfc.wftmax		= CAN_ISOTP_DEFAULT_RECV_WFTMAX;
+	so->ll.mtu		= CAN_ISOTP_DEFAULT_LL_MTU;
+	so->ll.tx_dl		= CAN_ISOTP_DEFAULT_LL_TX_DL;
+	so->ll.tx_flags		= CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
+
+	/* set ll_dl for tx path to similar place as for rx */
+	so->tx.ll_dl		= so->ll.tx_dl;
+
+	so->rx.state = ISOTP_IDLE;
+	so->tx.state = ISOTP_IDLE;
+
+	hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	so->rxtimer.function = isotp_rx_timer_handler;
+	hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	so->txtimer.function = isotp_tx_timer_handler;
+
+	tasklet_init(&so->txtsklet, isotp_tx_timer_tsklet, (unsigned long)so);
+
+	init_waitqueue_head(&so->wait);
+
+	so->notifier.notifier_call = isotp_notifier;
+	register_netdevice_notifier(&so->notifier);
+
+	return 0;
+}
+
+static const struct proto_ops isotp_ops = {
+	.family        = PF_CAN,
+	.release       = isotp_release,
+	.bind          = isotp_bind,
+	.connect       = sock_no_connect,
+	.socketpair    = sock_no_socketpair,
+	.accept        = sock_no_accept,
+	.getname       = isotp_getname,
+	.poll          = datagram_poll,
+	.ioctl         = can_ioctl,	/* use can_ioctl() from af_can.c */
+	.listen        = sock_no_listen,
+	.shutdown      = sock_no_shutdown,
+	.setsockopt    = isotp_setsockopt,
+	.getsockopt    = isotp_getsockopt,
+	.sendmsg       = isotp_sendmsg,
+	.recvmsg       = isotp_recvmsg,
+	.mmap          = sock_no_mmap,
+	.sendpage      = sock_no_sendpage,
+};
+
+static struct proto isotp_proto __read_mostly = {
+	.name       = "CAN_ISOTP",
+	.owner      = THIS_MODULE,
+	.obj_size   = sizeof(struct isotp_sock),
+	.init       = isotp_init,
+};
+
+static const struct can_proto isotp_can_proto = {
+	.type       = SOCK_DGRAM,
+	.protocol   = CAN_ISOTP,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33)
+	.capability = -1,
+#endif
+	.ops        = &isotp_ops,
+	.prot       = &isotp_proto,
+};
+
+static __init int isotp_module_init(void)
+{
+	int err;
+
+	printk(banner);
+
+	err = can_proto_register(&isotp_can_proto);
+	if (err < 0)
+		printk(KERN_ERR "can: registration of isotp protocol failed\n");
+
+	return err;
+}
+
+static __exit void isotp_module_exit(void)
+{
+	can_proto_unregister(&isotp_can_proto);
+}
+
+module_init(isotp_module_init);
+module_exit(isotp_module_exit);