Merge tag 'linux-can-next-for-5.4-20190904' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2019-09-04 j1939

this is a pull request for net-next/master consisting of 21 patches.

the first 12 patches are by me and target the CAN core infrastructure.
They clean up the names of variables , structs and struct members,
convert can_rx_register() to use max() instead of open coding it and
remove unneeded code from the can_pernet_exit() callback.

The next three patches are also by me and they introduce and make use of
the CAN midlayer private structure. It is used to hold protocol specific
per device data structures.

The next patch is by Oleksij Rempel, switches the
&net->can.rcvlists_lock from a spin_lock() to a spin_lock_bh(), so that
it can be used from NAPI (soft IRQ) context.

The next 4 patches are by Kurt Van Dijck, he first updates his email
address via mailmap and then extends sockaddr_can to include j1939
members.

The final patch is the collective effort of many entities (The j1939
authors: Oliver Hartkopp, Bastian Stender, Elenita Hinds, kbuild test
robot, Kurt Van Dijck, Maxime Jayat, Robin van der Gracht, Oleksij
Rempel, Marc Kleine-Budde). It adds support of SAE J1939 protocol to the
CAN networking stack.

SAE J1939 is the vehicle bus recommended practice used for communication
and diagnostics among vehicle components. Originating in the car and
heavy-duty truck industry in the United States, it is now widely used in
other parts of the world.

P.S.: This pull request doesn't invalidate my last pull request:
"pull-request: can-next 2019-09-03".
====================

Signed-off-by: David S. Miller <[e-mail]>

.mailmap

···
 Dengcheng Zhu <[e-mail]> <[e-mail]>
 Dengcheng Zhu <[e-mail]> <[e-mail]>
 Dengcheng Zhu <[e-mail]> <[e-mail]>
+<[e-mail]> <[e-mail]>
 Dmitry Eremin-Solenikov <[e-mail]>
 Dmitry Safonov <[e-mail]> <[e-mail]>
 Dmitry Safonov <[e-mail]> <[e-mail]>

Documentation/networking/index.rst

···
    devlink-trap
    devlink-trap-netdevsim
    ieee802154
+   j1939
    kapi
    z8530book
    msg_zerocopy

Documentation/networking/j1939.rst

···
+.. SPDX-License-Identifier: (GPL-2.0 OR MIT)
+
+===================
+J1939 Documentation
+===================
+
+Overview / What Is J1939
+========================
+
+SAE J1939 defines a higher layer protocol on CAN. It implements a more
+sophisticated addressing scheme and extends the maximum packet size above 8
+bytes. Several derived specifications exist, which differ from the original
+J1939 on the application level, like MilCAN A, NMEA2000 and especially
+ISO-11783 (ISOBUS). This last one specifies the so-called ETP (Extended
+Transport Protocol) which is has been included in this implementation. This
+results in a maximum packet size of ((2 ^ 24) - 1) * 7 bytes == 111 MiB.
+
+Specifications used
+-------------------
+
+* SAE J1939-21 : data link layer
+* SAE J1939-81 : network management
+* ISO 11783-6  : Virtual Terminal (Extended Transport Protocol)
+
+.. _j1939-motivation:
+
+Motivation
+==========
+
+Given the fact there's something like SocketCAN with an API similar to BSD
+sockets, we found some reasons to justify a kernel implementation for the
+addressing and transport methods used by J1939.
+
+* **Addressing:** when a process on an ECU communicates via J1939, it should
+  not necessarily know its source address. Although at least one process per
+  ECU should know the source address. Other processes should be able to reuse
+  that address. This way, address parameters for different processes
+  cooperating for the same ECU, are not duplicated. This way of working is
+  closely related to the UNIX concept where programs do just one thing, and do
+  it well.
+
+* **Dynamic addressing:** Address Claiming in J1939 is time critical.
+  Furthermore data transport should be handled properly during the address
+  negotiation. Putting this functionality in the kernel eliminates it as a
+  requirement for _every_ user space process that communicates via J1939. This
+  results in a consistent J1939 bus with proper addressing.
+
+* **Transport:** both TP & ETP reuse some PGNs to relay big packets over them.
+  Different processes may thus use the same TP & ETP PGNs without actually
+  knowing it. The individual TP & ETP sessions _must_ be serialized
+  (synchronized) between different processes. The kernel solves this problem
+  properly and eliminates the serialization (synchronization) as a requirement
+  for _every_ user space process that communicates via J1939.
+
+J1939 defines some other features (relaying, gateway, fast packet transport,
+...). In-kernel code for these would not contribute to protocol stability.
+Therefore, these parts are left to user space.
+
+The J1939 sockets operate on CAN network devices (see SocketCAN). Any J1939
+user space library operating on CAN raw sockets will still operate properly.
+Since such library does not communicate with the in-kernel implementation, care
+must be taken that these two do not interfere. In practice, this means they
+cannot share ECU addresses. A single ECU (or virtual ECU) address is used by
+the library exclusively, or by the in-kernel system exclusively.
+
+J1939 concepts
+==============
+
+PGN
+---
+
+The PGN (Parameter Group Number) is a number to identify a packet. The PGN
+is composed as follows:
+1 bit  : Reserved Bit
+1 bit  : Data Page
+8 bits : PF (PDU Format)
+8 bits : PS (PDU Specific)
+
+In J1939-21 distinction is made between PDU1 format (where PF < 240) and PDU2
+format (where PF >= 240). Furthermore, when using PDU2 format, the PS-field
+contains a so-called Group Extension, which is part of the PGN. When using PDU2
+format, the Group Extension is set in the PS-field.
+
+On the other hand, when using PDU1 format, the PS-field contains a so-called
+Destination Address, which is _not_ part of the PGN. When communicating a PGN
+from user space to kernel (or visa versa) and PDU2 format is used, the PS-field
+of the PGN shall be set to zero. The Destination Address shall be set
+elsewhere.
+
+Regarding PGN mapping to 29-bit CAN identifier, the Destination Address shall
+be get/set from/to the appropriate bits of the identifier by the kernel.
+
+
+Addressing
+----------
+
+Both static and dynamic addressing methods can be used.
+
+For static addresses, no extra checks are made by the kernel, and provided
+addresses are considered right. This responsibility is for the OEM or system
+integrator.
+
+For dynamic addressing, so-called Address Claiming, extra support is foreseen
+in the kernel. In J1939 any ECU is known by it's 64-bit NAME. At the moment of
+a successful address claim, the kernel keeps track of both NAME and source
+address being claimed. This serves as a base for filter schemes. By default,
+packets with a destination that is not locally, will be rejected.
+
+Mixed mode packets (from a static to a dynamic address or vice versa) are
+allowed. The BSD sockets define separate API calls for getting/setting the
+local & remote address and are applicable for J1939 sockets.
+
+Filtering
+---------
+
+J1939 defines white list filters per socket that a user can set in order to
+receive a subset of the J1939 traffic. Filtering can be based on:
+
+* SA
+* SOURCE_NAME
+* PGN
+
+When multiple filters are in place for a single socket, and a packet comes in
+that matches several of those filters, the packet is only received once for
+that socket.
+
+How to Use J1939
+================
+
+API Calls
+---------
+
+On CAN, you first need to open a socket for communicating over a CAN network.
+To use J1939, #include <linux/can/j1939.h>. From there, <linux/can.h> will be
+included too. To open a socket, use:
+
+.. code-block:: C
+
+    s = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
+
+J1939 does use SOCK_DGRAM sockets. In the J1939 specification, connections are
+mentioned in the context of transport protocol sessions. These still deliver
+packets to the other end (using several CAN packets). SOCK_STREAM is not
+supported.
+
+After the successful creation of the socket, you would normally use the bind(2)
+and/or connect(2) system call to bind the socket to a CAN interface.  After
+binding and/or connecting the socket, you can read(2) and write(2) from/to the
+socket or use send(2), sendto(2), sendmsg(2) and the recv*() counterpart
+operations on the socket as usual. There are also J1939 specific socket options
+described below.
+
+In order to send data, a bind(2) must have been successful. bind(2) assigns a
+local address to a socket.
+
+Different from CAN is that the payload data is just the data that get send,
+without it's header info. The header info is derived from the sockaddr supplied
+to bind(2), connect(2), sendto(2) and recvfrom(2). A write(2) with size 4 will
+result in a packet with 4 bytes.
+
+The sockaddr structure has extensions for use with J1939 as specified below:
+
+.. code-block:: C
+
+      struct sockaddr_can {
+         sa_family_t can_family;
+         int         can_ifindex;
+         union {
+            struct {
+               __u64 name;
+                        /* pgn:
+                         * 8 bit: PS in PDU2 case, else 0
+                         * 8 bit: PF
+                         * 1 bit: DP
+                         * 1 bit: reserved
+                         */
+               __u32 pgn;
+               __u8  addr;
+            } j1939;
+         } can_addr;
+      }
+
+can_family & can_ifindex serve the same purpose as for other SocketCAN sockets.
+
+can_addr.j1939.pgn specifies the PGN (max 0x3ffff). Individual bits are
+specified above.
+
+can_addr.j1939.name contains the 64-bit J1939 NAME.
+
+can_addr.j1939.addr contains the address.
+
+The bind(2) system call assigns the local address, i.e. the source address when
+sending packages. If a PGN during bind(2) is set, it's used as a RX filter.
+I.e.  only packets with a matching PGN are received. If an ADDR or NAME is set
+it is used as a receive filter, too. It will match the destination NAME or ADDR
+of the incoming packet. The NAME filter will work only if appropriate Address
+Claiming for this name was done on the CAN bus and registered/cached by the
+kernel.
+
+On the other hand connect(2) assigns the remote address, i.e. the destination
+address. The PGN from connect(2) is used as the default PGN when sending
+packets. If ADDR or NAME is set it will be used as the default destination ADDR
+or NAME. Further a set ADDR or NAME during connect(2) is used as a receive
+filter. It will match the source NAME or ADDR of the incoming packet.
+
+Both write(2) and send(2) will send a packet with local address from bind(2) and
+the remote address from connect(2). Use sendto(2) to overwrite the destination
+address.
+
+If can_addr.j1939.name is set (!= 0) the NAME is looked up by the kernel and
+the corresponding ADDR is used. If can_addr.j1939.name is not set (== 0),
+can_addr.j1939.addr is used.
+
+When creating a socket, reasonable defaults are set. Some options can be
+modified with setsockopt(2) & getsockopt(2).
+
+RX path related options:
+
+- SO_J1939_FILTER - configure array of filters
+- SO_J1939_PROMISC - disable filters set by bind(2) and connect(2)
+
+By default no broadcast packets can be send or received. To enable sending or
+receiving broadcast packets use the socket option SO_BROADCAST:
+
+.. code-block:: C
+
+     int value = 1;
+     setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &value, sizeof(value));
+
+The following diagram illustrates the RX path:
+
+.. code::
+
+                    +--------------------+
+                    |  incoming packet   |
+                    +--------------------+
+                              |
+                              V
+                    +--------------------+
+                    | SO_J1939_PROMISC?  |
+                    +--------------------+
+                             |  |
+                         no  |  | yes
+                             |  |
+                   .---------'  `---------.
+                   |                      |
+     +---------------------------+        |
+     | bind() + connect() +      |        |
+     | SOCK_BROADCAST filter     |        |
+     +---------------------------+        |
+                   |                      |
+                   |<---------------------'
+                   V
+     +---------------------------+
+     |      SO_J1939_FILTER      |
+     +---------------------------+
+                   |
+                   V
+     +---------------------------+
+     |        socket recv()      |
+     +---------------------------+
+
+TX path related options:
+SO_J1939_SEND_PRIO - change default send priority for the socket
+
+Message Flags during send() and Related System Calls
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+send(2), sendto(2) and sendmsg(2) take a 'flags' argument. Currently
+supported flags are:
+
+* MSG_DONTWAIT, i.e. non-blocking operation.
+
+recvmsg(2)
+^^^^^^^^^
+
+In most cases recvmsg(2) is needed if you want to extract more information than
+recvfrom(2) can provide. For example package priority and timestamp. The
+Destination Address, name and packet priority (if applicable) are attached to
+the msghdr in the recvmsg(2) call. They can be extracted using cmsg(3) macros,
+with cmsg_level == SOL_J1939 && cmsg_type == SCM_J1939_DEST_ADDR,
+SCM_J1939_DEST_NAME or SCM_J1939_PRIO. The returned data is a uint8_t for
+priority and dst_addr, and uint64_t for dst_name.
+
+.. code-block:: C
+
+	uint8_t priority, dst_addr;
+	uint64_t dst_name;
+
+	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+		switch (cmsg->cmsg_level) {
+		case SOL_CAN_J1939:
+			if (cmsg->cmsg_type == SCM_J1939_DEST_ADDR)
+				dst_addr = *CMSG_DATA(cmsg);
+			else if (cmsg->cmsg_type == SCM_J1939_DEST_NAME)
+				memcpy(&dst_name, CMSG_DATA(cmsg), cmsg->cmsg_len - CMSG_LEN(0));
+			else if (cmsg->cmsg_type == SCM_J1939_PRIO)
+				priority = *CMSG_DATA(cmsg);
+			break;
+		}
+	}
+
+Dynamic Addressing
+------------------
+
+Distinction has to be made between using the claimed address and doing an
+address claim. To use an already claimed address, one has to fill in the
+j1939.name member and provide it to bind(2). If the name had claimed an address
+earlier, all further messages being sent will use that address. And the
+j1939.addr member will be ignored.
+
+An exception on this is PGN 0x0ee00. This is the "Address Claim/Cannot Claim
+Address" message and the kernel will use the j1939.addr member for that PGN if
+necessary.
+
+To claim an address following code example can be used:
+
+.. code-block:: C
+
+	struct sockaddr_can baddr = {
+		.can_family = AF_CAN,
+		.can_addr.j1939 = {
+			.name = name,
+			.addr = J1939_IDLE_ADDR,
+			.pgn = J1939_NO_PGN,	/* to disable bind() rx filter for PGN */
+		},
+		.can_ifindex = if_nametoindex("can0"),
+	};
+
+	bind(sock, (struct sockaddr *)&baddr, sizeof(baddr));
+
+	/* for Address Claiming broadcast must be allowed */
+	int value = 1;
+	setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &value, sizeof(value));
+
+	/* configured advanced RX filter with PGN needed for Address Claiming */
+	const struct j1939_filter filt[] = {
+		{
+			.pgn = J1939_PGN_ADDRESS_CLAIMED,
+			.pgn_mask = J1939_PGN_PDU1_MAX,
+		}, {
+			.pgn = J1939_PGN_ADDRESS_REQUEST,
+			.pgn_mask = J1939_PGN_PDU1_MAX,
+		}, {
+			.pgn = J1939_PGN_ADDRESS_COMMANDED,
+			.pgn_mask = J1939_PGN_MAX,
+		},
+	};
+
+	setsockopt(sock, SOL_CAN_J1939, SO_J1939_FILTER, &filt, sizeof(filt));
+
+	uint64_t dat = htole64(name);
+	const struct sockaddr_can saddr = {
+		.can_family = AF_CAN,
+		.can_addr.j1939 = {
+			.pgn = J1939_PGN_ADDRESS_CLAIMED,
+			.addr = J1939_NO_ADDR,
+		},
+	};
+
+	/* Afterwards do a sendto(2) with data set to the NAME (Little Endian). If the
+	 * NAME provided, does not match the j1939.name provided to bind(2), EPROTO
+	 * will be returned.
+	 */
+	sendto(sock, dat, sizeof(dat), 0, (const struct sockaddr *)&saddr, sizeof(saddr));
+
+If no-one else contests the address claim within 250ms after transmission, the
+kernel marks the NAME-SA assignment as valid. The valid assignment will be kept
+among other valid NAME-SA assignments. From that point, any socket bound to the
+NAME can send packets.
+
+If another ECU claims the address, the kernel will mark the NAME-SA expired.
+No socket bound to the NAME can send packets (other than address claims). To
+claim another address, some socket bound to NAME, must bind(2) again, but with
+only j1939.addr changed to the new SA, and must then send a valid address claim
+packet. This restarts the state machine in the kernel (and any other
+participant on the bus) for this NAME.
+
+can-utils also include the jacd tool, so it can be used as code example or as
+default Address Claiming daemon.
+
+Send Examples
+-------------
+
+Static Addressing
+^^^^^^^^^^^^^^^^^
+
+This example will send a PGN (0x12300) from SA 0x20 to DA 0x30.
+
+Bind:
+
+.. code-block:: C
+
+	struct sockaddr_can baddr = {
+		.can_family = AF_CAN,
+		.can_addr.j1939 = {
+			.name = J1939_NO_NAME,
+			.addr = 0x20,
+			.pgn = J1939_NO_PGN,
+		},
+		.can_ifindex = if_nametoindex("can0"),
+	};
+
+	bind(sock, (struct sockaddr *)&baddr, sizeof(baddr));
+
+Now, the socket 'sock' is bound to the SA 0x20. Since no connect(2) was called,
+at this point we can use only sendto(2) or sendmsg(2).
+
+Send:
+
+.. code-block:: C
+
+	const struct sockaddr_can saddr = {
+		.can_family = AF_CAN,
+		.can_addr.j1939 = {
+			.name = J1939_NO_NAME;
+			.pgn = 0x30,
+			.addr = 0x12300,
+		},
+	};
+
+	sendto(sock, dat, sizeof(dat), 0, (const struct sockaddr *)&saddr, sizeof(saddr));

MAINTAINERS

···
 F:	include/uapi/linux/can/raw.h
 F:	include/uapi/linux/can/gw.h
 
+CAN-J1939 NETWORK LAYER
+M:	Robin van der Gracht <[e-mail]>
+M:	Oleksij Rempel <[e-mail]>
+R:	Pengutronix Kernel Team <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	Documentation/networking/j1939.txt
+F:	net/can/j1939/
+F:	include/uapi/linux/can/j1939.h
+
 CAPABILITIES
 M:	Serge Hallyn <[e-mail]>
 L:	[e-mail]

drivers/net/can/dev.c

···
 #include <linux/if_arp.h>
 #include <linux/workqueue.h>
 #include <linux/can.h>
+#include <linux/can/can-ml.h>
 #include <linux/can/dev.h>
 #include <linux/can/skb.h>
 #include <linux/can/netlink.h>
···
 	struct can_priv *priv;
 	int size;
 
+	/* We put the driver's priv, the CAN mid layer priv and the
+	 * echo skb into the netdevice's priv. The memory layout for
+	 * the netdev_priv is like this:
+	 *
+	 * +-------------------------+
+	 * | driver's priv           |
+	 * +-------------------------+
+	 * | struct can_ml_priv      |
+	 * +-------------------------+
+	 * | array of struct sk_buff |
+	 * +-------------------------+
+	 */
+
+	size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv);
+
 	if (echo_skb_max)
-		size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
+		size = ALIGN(size, sizeof(struct sk_buff *)) +
 			echo_skb_max * sizeof(struct sk_buff *);
-	else
-		size = sizeof_priv;
 
 	dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
 			       txqs, rxqs);
···
 	priv = netdev_priv(dev);
 	priv->dev = dev;
 
+	dev->ml_priv = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN);
+
 	if (echo_skb_max) {
 		priv->echo_skb_max = echo_skb_max;
 		priv->echo_skb = (void *)priv +
-			ALIGN(sizeof_priv, sizeof(struct sk_buff *));
+			(size - echo_skb_max * sizeof(struct sk_buff *));
 	}
 
 	priv->state = CAN_STATE_STOPPED;

drivers/net/can/slcan.c

···
 #include <linux/workqueue.h>
 #include <linux/can.h>
 #include <linux/can/skb.h>
+#include <linux/can/can-ml.h>
 
 MODULE_ALIAS_LDISC(N_SLCAN);
 MODULE_DESCRIPTION("serial line CAN interface");
···
 	char name[IFNAMSIZ];
 	struct net_device *dev = NULL;
 	struct slcan       *sl;
+	int size;
 
 	for (i = 0; i < maxdev; i++) {
 		dev = slcan_devs[i];
···
 		return NULL;
 
 	sprintf(name, "slcan%d", i);
-	dev = alloc_netdev(sizeof(*sl), name, NET_NAME_UNKNOWN, slc_setup);
+	size = ALIGN(sizeof(*sl), NETDEV_ALIGN) + sizeof(struct can_ml_priv);
+	dev = alloc_netdev(size, name, NET_NAME_UNKNOWN, slc_setup);
 	if (!dev)
 		return NULL;
 
 	dev->base_addr  = i;
 	sl = netdev_priv(dev);
+	dev->ml_priv = (void *)sl + ALIGN(sizeof(*sl), NETDEV_ALIGN);
 
 	/* Initialize channel control data */
 	sl->magic = SLCAN_MAGIC;

drivers/net/can/vcan.c

···
 #include <linux/if_arp.h>
 #include <linux/if_ether.h>
 #include <linux/can.h>
+#include <linux/can/can-ml.h>
 #include <linux/can/dev.h>
 #include <linux/can/skb.h>
 #include <linux/slab.h>
···
 	dev->addr_len		= 0;
 	dev->tx_queue_len	= 0;
 	dev->flags		= IFF_NOARP;
+	dev->ml_priv		= netdev_priv(dev);
 
 	/* set flags according to driver capabilities */
 	if (echo)
···
 }
 
 static struct rtnl_link_ops vcan_link_ops __read_mostly = {
-	.kind	= DRV_NAME,
-	.setup	= vcan_setup,
+	.kind = DRV_NAME,
+	.priv_size = sizeof(struct can_ml_priv),
+	.setup = vcan_setup,
 };
 
 static __init int vcan_init_module(void)

drivers/net/can/vxcan.c

···
 #include <linux/can/dev.h>
 #include <linux/can/skb.h>
 #include <linux/can/vxcan.h>
+#include <linux/can/can-ml.h>
 #include <linux/slab.h>
 #include <net/rtnetlink.h>
 
···
 	dev->flags		= (IFF_NOARP|IFF_ECHO);
 	dev->netdev_ops		= &vxcan_netdev_ops;
 	dev->needs_free_netdev	= true;
+	dev->ml_priv		= netdev_priv(dev) + ALIGN(sizeof(struct vxcan_priv), NETDEV_ALIGN);
 }
 
 /* forward declaration for rtnl_create_link() */
···
 
 static struct rtnl_link_ops vxcan_link_ops = {
 	.kind		= DRV_NAME,
-	.priv_size	= sizeof(struct vxcan_priv),
+	.priv_size	= ALIGN(sizeof(struct vxcan_priv), NETDEV_ALIGN) + sizeof(struct can_ml_priv),
 	.setup		= vxcan_setup,
 	.newlink	= vxcan_newlink,
 	.dellink	= vxcan_dellink,

include/linux/can/can-ml.h

···
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/* Copyright (c) 2002-2007 Volkswagen Group Electronic Research
+ * Copyright (c) 2017 Pengutronix, Marc Kleine-Budde <[e-mail]>
+ *
+ * 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 CAN_ML_H
+#define CAN_ML_H
+
+#include <linux/can.h>
+#include <linux/list.h>
+
+#define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS)
+#define CAN_EFF_RCV_HASH_BITS 10
+#define CAN_EFF_RCV_ARRAY_SZ (1 << CAN_EFF_RCV_HASH_BITS)
+
+enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_MAX };
+
+struct can_dev_rcv_lists {
+	struct hlist_head rx[RX_MAX];
+	struct hlist_head rx_sff[CAN_SFF_RCV_ARRAY_SZ];
+	struct hlist_head rx_eff[CAN_EFF_RCV_ARRAY_SZ];
+	int entries;
+};
+
+struct can_ml_priv {
+	struct can_dev_rcv_lists dev_rcv_lists;
+#ifdef CAN_J1939
+	struct j1939_priv *j1939_priv;
+#endif
+};
+
+#endif /* CAN_ML_H */

include/linux/can/core.h

···
 	struct proto *prot;
 };
 
+/* required_size
+ * macro to find the minimum size of a struct
+ * that includes a requested member
+ */
+#define CAN_REQUIRED_SIZE(struct_type, member) \
+	(offsetof(typeof(struct_type), member) + \
+	 sizeof(((typeof(struct_type) *)(NULL))->member))
+
 /* function prototypes for the CAN networklayer core (af_can.c) */
 
 extern int  can_proto_register(const struct can_proto *cp);

include/net/netns/can.h

···
 #include <linux/spinlock.h>
 
 struct can_dev_rcv_lists;
-struct s_stats;
-struct s_pstats;
+struct can_pkg_stats;
+struct can_rcv_lists_stats;
 
 struct netns_can {
 #if IS_ENABLED(CONFIG_PROC_FS)
···
 #endif
 
 	/* receive filters subscribed for 'all' CAN devices */
-	struct can_dev_rcv_lists *can_rx_alldev_list;
-	spinlock_t can_rcvlists_lock;
-	struct timer_list can_stattimer;/* timer for statistics update */
-	struct s_stats *can_stats;	/* packet statistics */
-	struct s_pstats *can_pstats;	/* receive list statistics */
+	struct can_dev_rcv_lists *rx_alldev_list;
+	spinlock_t rcvlists_lock;
+	struct timer_list stattimer; /* timer for statistics update */
+	struct can_pkg_stats *pkg_stats;
+	struct can_rcv_lists_stats *rcv_lists_stats;
 
 	/* CAN GW per-net gateway jobs */
 	struct hlist_head cgw_list;

include/uapi/linux/can.h

···
 #define CAN_TP20	4 /* VAG Transport Protocol v2.0 */
 #define CAN_MCNET	5 /* Bosch MCNet */
 #define CAN_ISOTP	6 /* ISO 15765-2 Transport Protocol */
-#define CAN_NPROTO	7
+#define CAN_J1939	7 /* SAE J1939 */
+#define CAN_NPROTO	8
 
 #define SOL_CAN_BASE 100
 
···
 	union {
 		/* transport protocol class address information (e.g. ISOTP) */
 		struct { canid_t rx_id, tx_id; } tp;
+
+		/* J1939 address information */
+		struct {
+			/* 8 byte name when using dynamic addressing */
+			__u64 name;
+
+			/* pgn:
+			 * 8 bit: PS in PDU2 case, else 0
+			 * 8 bit: PF
+			 * 1 bit: DP
+			 * 1 bit: reserved
+			 */
+			__u32 pgn;
+
+			/* 1 byte address */
+			__u8 addr;
+		} j1939;
 
 		/* reserved for future CAN protocols address information */
 	} can_addr;

include/uapi/linux/can/j1939.h

···
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * j1939.h
+ *
+ * Copyright (c) 2010-2011 EIA Electronics
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _UAPI_CAN_J1939_H_
+#define _UAPI_CAN_J1939_H_
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/can.h>
+
+#define J1939_MAX_UNICAST_ADDR 0xfd
+#define J1939_IDLE_ADDR 0xfe
+#define J1939_NO_ADDR 0xff		/* == broadcast or no addr */
+#define J1939_NO_NAME 0
+#define J1939_PGN_REQUEST 0x0ea00		/* Request PG */
+#define J1939_PGN_ADDRESS_CLAIMED 0x0ee00	/* Address Claimed */
+#define J1939_PGN_ADDRESS_COMMANDED 0x0fed8	/* Commanded Address */
+#define J1939_PGN_PDU1_MAX 0x3ff00
+#define J1939_PGN_MAX 0x3ffff
+#define J1939_NO_PGN 0x40000
+
+/* J1939 Parameter Group Number
+ *
+ * bit 0-7	: PDU Specific (PS)
+ * bit 8-15	: PDU Format (PF)
+ * bit 16	: Data Page (DP)
+ * bit 17	: Reserved (R)
+ * bit 19-31	: set to zero
+ */
+typedef __u32 pgn_t;
+
+/* J1939 Priority
+ *
+ * bit 0-2	: Priority (P)
+ * bit 3-7	: set to zero
+ */
+typedef __u8 priority_t;
+
+/* J1939 NAME
+ *
+ * bit 0-20	: Identity Number
+ * bit 21-31	: Manufacturer Code
+ * bit 32-34	: ECU Instance
+ * bit 35-39	: Function Instance
+ * bit 40-47	: Function
+ * bit 48	: Reserved
+ * bit 49-55	: Vehicle System
+ * bit 56-59	: Vehicle System Instance
+ * bit 60-62	: Industry Group
+ * bit 63	: Arbitrary Address Capable
+ */
+typedef __u64 name_t;
+
+/* J1939 socket options */
+#define SOL_CAN_J1939 (SOL_CAN_BASE + CAN_J1939)
+enum {
+	SO_J1939_FILTER = 1,	/* set filters */
+	SO_J1939_PROMISC = 2,	/* set/clr promiscuous mode */
+	SO_J1939_SEND_PRIO = 3,
+	SO_J1939_ERRQUEUE = 4,
+};
+
+enum {
+	SCM_J1939_DEST_ADDR = 1,
+	SCM_J1939_DEST_NAME = 2,
+	SCM_J1939_PRIO = 3,
+	SCM_J1939_ERRQUEUE = 4,
+};
+
+enum {
+	J1939_NLA_PAD,
+	J1939_NLA_BYTES_ACKED,
+};
+
+enum {
+	J1939_EE_INFO_NONE,
+	J1939_EE_INFO_TX_ABORT,
+};
+
+struct j1939_filter {
+	name_t name;
+	name_t name_mask;
+	pgn_t pgn;
+	pgn_t pgn_mask;
+	__u8 addr;
+	__u8 addr_mask;
+};
+
+#define J1939_FILTER_MAX 512 /* maximum number of j1939_filter set via setsockopt() */
+
+#endif /* !_UAPI_CAN_J1939_H_ */

net/can/Kconfig

···
 	  They can be modified with AND/OR/XOR/SET operations as configured
 	  by the netlink configuration interface known e.g. from iptables.
 
+source "net/can/j1939/Kconfig"
+
 source "drivers/net/can/Kconfig"
 
 endif

net/can/Makefile

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

net/can/af_can.c

···
 #include <linux/can.h>
 #include <linux/can/core.h>
 #include <linux/can/skb.h>
+#include <linux/can/can-ml.h>
 #include <linux/ratelimit.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
···
 {
 	struct sk_buff *newskb = NULL;
 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
-	struct s_stats *can_stats = dev_net(skb->dev)->can.can_stats;
+	struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;
 	int err = -EINVAL;
 
 	if (skb->len == CAN_MTU) {
···
 		netif_rx_ni(newskb);
 
 	/* update statistics */
-	can_stats->tx_frames++;
-	can_stats->tx_frames_delta++;
+	pkg_stats->tx_frames++;
+	pkg_stats->tx_frames_delta++;
 
 	return 0;
 
···
 
 /* af_can rx path */
 
-static struct can_dev_rcv_lists *find_dev_rcv_lists(struct net *net,
-						    struct net_device *dev)
+static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net,
+							struct net_device *dev)
 {
-	if (!dev)
-		return net->can.can_rx_alldev_list;
-	else
-		return (struct can_dev_rcv_lists *)dev->ml_priv;
+	if (dev) {
+		struct can_ml_priv *ml_priv = dev->ml_priv;
+		return &ml_priv->dev_rcv_lists;
+	} else {
+		return net->can.rx_alldev_list;
+	}
 }
 
 /**
···
 }
 
 /**
- * find_rcv_list - determine optimal filterlist inside device filter struct
+ * can_rcv_list_find - determine optimal filterlist inside device filter struct
  * @can_id: pointer to CAN identifier of a given can_filter
  * @mask: pointer to CAN mask of a given can_filter
  * @d: pointer to the device filter struct
···
  *  Constistency checked mask.
  *  Reduced can_id to have a preprocessed filter compare value.
  */
-static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
-					struct can_dev_rcv_lists *d)
+static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
+					    struct can_dev_rcv_lists *dev_rcv_lists)
 {
 	canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
 
···
 	if (*mask & CAN_ERR_FLAG) {
 		/* clear CAN_ERR_FLAG in filter entry */
 		*mask &= CAN_ERR_MASK;
-		return &d->rx[RX_ERR];
+		return &dev_rcv_lists->rx[RX_ERR];
 	}
 
 	/* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
···
 
 	/* inverse can_id/can_mask filter */
 	if (inv)
-		return &d->rx[RX_INV];
+		return &dev_rcv_lists->rx[RX_INV];
 
 	/* mask == 0 => no condition testing at receive time */
 	if (!(*mask))
-		return &d->rx[RX_ALL];
+		return &dev_rcv_lists->rx[RX_ALL];
 
 	/* extra filterlists for the subscription of a single non-RTR can_id */
 	if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
 	    !(*can_id & CAN_RTR_FLAG)) {
 		if (*can_id & CAN_EFF_FLAG) {
 			if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
-				return &d->rx_eff[effhash(*can_id)];
+				return &dev_rcv_lists->rx_eff[effhash(*can_id)];
 		} else {
 			if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
-				return &d->rx_sff[*can_id];
+				return &dev_rcv_lists->rx_sff[*can_id];
 		}
 	}
 
 	/* default: filter via can_id/can_mask */
-	return &d->rx[RX_FIL];
+	return &dev_rcv_lists->rx[RX_FIL];
 }
 
 /**
···
 		    canid_t mask, void (*func)(struct sk_buff *, void *),
 		    void *data, char *ident, struct sock *sk)
 {
-	struct receiver *r;
-	struct hlist_head *rl;
-	struct can_dev_rcv_lists *d;
-	struct s_pstats *can_pstats = net->can.can_pstats;
+	struct receiver *rcv;
+	struct hlist_head *rcv_list;
+	struct can_dev_rcv_lists *dev_rcv_lists;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
 	int err = 0;
 
 	/* insert new receiver  (dev,canid,mask) -> (func,data) */
···
 	if (dev && !net_eq(net, dev_net(dev)))
 		return -ENODEV;
 
-	r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
-	if (!r)
+	rcv = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
+	if (!rcv)
 		return -ENOMEM;
 
-	spin_lock(&net->can.can_rcvlists_lock);
+	spin_lock_bh(&net->can.rcvlists_lock);
 
-	d = find_dev_rcv_lists(net, dev);
-	if (d) {
-		rl = find_rcv_list(&can_id, &mask, d);
+	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
+	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
 
-		r->can_id  = can_id;
-		r->mask    = mask;
-		r->matches = 0;
-		r->func    = func;
-		r->data    = data;
-		r->ident   = ident;
-		r->sk      = sk;
+	rcv->can_id = can_id;
+	rcv->mask = mask;
+	rcv->matches = 0;
+	rcv->func = func;
+	rcv->data = data;
+	rcv->ident = ident;
+	rcv->sk = sk;
 
-		hlist_add_head_rcu(&r->list, rl);
-		d->entries++;
+	hlist_add_head_rcu(&rcv->list, rcv_list);
+	dev_rcv_lists->entries++;
 
-		can_pstats->rcv_entries++;
-		if (can_pstats->rcv_entries_max < can_pstats->rcv_entries)
-			can_pstats->rcv_entries_max = can_pstats->rcv_entries;
-	} else {
-		kmem_cache_free(rcv_cache, r);
-		err = -ENODEV;
-	}
-
-	spin_unlock(&net->can.can_rcvlists_lock);
+	rcv_lists_stats->rcv_entries++;
+	rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max,
+					       rcv_lists_stats->rcv_entries);
+	spin_unlock_bh(&net->can.rcvlists_lock);
 
 	return err;
 }
···
 /* can_rx_delete_receiver - rcu callback for single receiver entry removal */
 static void can_rx_delete_receiver(struct rcu_head *rp)
 {
-	struct receiver *r = container_of(rp, struct receiver, rcu);
-	struct sock *sk = r->sk;
+	struct receiver *rcv = container_of(rp, struct receiver, rcu);
+	struct sock *sk = rcv->sk;
 
-	kmem_cache_free(rcv_cache, r);
+	kmem_cache_free(rcv_cache, rcv);
 	if (sk)
 		sock_put(sk);
 }
···
 		       canid_t mask, void (*func)(struct sk_buff *, void *),
 		       void *data)
 {
-	struct receiver *r = NULL;
-	struct hlist_head *rl;
-	struct s_pstats *can_pstats = net->can.can_pstats;
-	struct can_dev_rcv_lists *d;
+	struct receiver *rcv = NULL;
+	struct hlist_head *rcv_list;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
+	struct can_dev_rcv_lists *dev_rcv_lists;
 
 	if (dev && dev->type != ARPHRD_CAN)
 		return;
···
 	if (dev && !net_eq(net, dev_net(dev)))
 		return;
 
-	spin_lock(&net->can.can_rcvlists_lock);
+	spin_lock_bh(&net->can.rcvlists_lock);
 
-	d = find_dev_rcv_lists(net, dev);
-	if (!d) {
-		pr_err("BUG: receive list not found for dev %s, id %03X, mask %03X\n",
-		       DNAME(dev), can_id, mask);
-		goto out;
-	}
-
-	rl = find_rcv_list(&can_id, &mask, d);
+	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
+	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
 
 	/* Search the receiver list for the item to delete.  This should
 	 * exist, since no receiver may be unregistered that hasn't
 	 * been registered before.
 	 */
-
-	hlist_for_each_entry_rcu(r, rl, list) {
-		if (r->can_id == can_id && r->mask == mask &&
-		    r->func == func && r->data == data)
+	hlist_for_each_entry_rcu(rcv, rcv_list, list) {
+		if (rcv->can_id == can_id && rcv->mask == mask &&
+		    rcv->func == func && rcv->data == data)
 			break;
 	}
 
 	/* Check for bugs in CAN protocol implementations using af_can.c:
-	 * 'r' will be NULL if no matching list item was found for removal.
+	 * 'rcv' will be NULL if no matching list item was found for removal.
 	 */
-
-	if (!r) {
+	if (!rcv) {
 		WARN(1, "BUG: receive list entry not found for dev %s, id %03X, mask %03X\n",
 		     DNAME(dev), can_id, mask);
 		goto out;
 	}
 
-	hlist_del_rcu(&r->list);
-	d->entries--;
+	hlist_del_rcu(&rcv->list);
+	dev_rcv_lists->entries--;
 
-	if (can_pstats->rcv_entries > 0)
-		can_pstats->rcv_entries--;
-
-	/* remove device structure requested by NETDEV_UNREGISTER */
-	if (d->remove_on_zero_entries && !d->entries) {
-		kfree(d);
-		dev->ml_priv = NULL;
-	}
+	if (rcv_lists_stats->rcv_entries > 0)
+		rcv_lists_stats->rcv_entries--;
 
  out:
-	spin_unlock(&net->can.can_rcvlists_lock);
+	spin_unlock_bh(&net->can.rcvlists_lock);
 
 	/* schedule the receiver item for deletion */
-	if (r) {
-		if (r->sk)
-			sock_hold(r->sk);
-		call_rcu(&r->rcu, can_rx_delete_receiver);
+	if (rcv) {
+		if (rcv->sk)
+			sock_hold(rcv->sk);
+		call_rcu(&rcv->rcu, can_rx_delete_receiver);
 	}
 }
 EXPORT_SYMBOL(can_rx_unregister);
 
-static inline void deliver(struct sk_buff *skb, struct receiver *r)
+static inline void deliver(struct sk_buff *skb, struct receiver *rcv)
 {
-	r->func(skb, r->data);
-	r->matches++;
+	rcv->func(skb, rcv->data);
+	rcv->matches++;
 }
 
-static int can_rcv_filter(struct can_dev_rcv_lists *d, struct sk_buff *skb)
+static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb)
 {
-	struct receiver *r;
+	struct receiver *rcv;
 	int matches = 0;
 	struct can_frame *cf = (struct can_frame *)skb->data;
 	canid_t can_id = cf->can_id;
 
-	if (d->entries == 0)
+	if (dev_rcv_lists->entries == 0)
 		return 0;
 
 	if (can_id & CAN_ERR_FLAG) {
 		/* check for error message frame entries only */
-		hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) {
-			if (can_id & r->mask) {
-				deliver(skb, r);
+		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) {
+			if (can_id & rcv->mask) {
+				deliver(skb, rcv);
 				matches++;
 			}
 		}
···
 	}
 
 	/* check for unfiltered entries */
-	hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) {
-		deliver(skb, r);
+	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) {
+		deliver(skb, rcv);
 		matches++;
 	}
 
 	/* check for can_id/mask entries */
-	hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) {
-		if ((can_id & r->mask) == r->can_id) {
-			deliver(skb, r);
+	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) {
+		if ((can_id & rcv->mask) == rcv->can_id) {
+			deliver(skb, rcv);
 			matches++;
 		}
 	}
 
 	/* check for inverted can_id/mask entries */
-	hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) {
-		if ((can_id & r->mask) != r->can_id) {
-			deliver(skb, r);
+	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) {
+		if ((can_id & rcv->mask) != rcv->can_id) {
+			deliver(skb, rcv);
 			matches++;
 		}
 	}
···
 		return matches;
 
 	if (can_id & CAN_EFF_FLAG) {
-		hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) {
-			if (r->can_id == can_id) {
-				deliver(skb, r);
+		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) {
+			if (rcv->can_id == can_id) {
+				deliver(skb, rcv);
 				matches++;
 			}
 		}
 	} else {
 		can_id &= CAN_SFF_MASK;
-		hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) {
-			deliver(skb, r);
+		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) {
+			deliver(skb, rcv);
 			matches++;
 		}
 	}
···
 
 static void can_receive(struct sk_buff *skb, struct net_device *dev)
 {
-	struct can_dev_rcv_lists *d;
+	struct can_dev_rcv_lists *dev_rcv_lists;
 	struct net *net = dev_net(dev);
-	struct s_stats *can_stats = net->can.can_stats;
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
 	int matches;
 
 	/* update statistics */
-	can_stats->rx_frames++;
-	can_stats->rx_frames_delta++;
+	pkg_stats->rx_frames++;
+	pkg_stats->rx_frames_delta++;
 
 	/* create non-zero unique skb identifier together with *skb */
 	while (!(can_skb_prv(skb)->skbcnt))
···
 	rcu_read_lock();
 
 	/* deliver the packet to sockets listening on all devices */
-	matches = can_rcv_filter(net->can.can_rx_alldev_list, skb);
+	matches = can_rcv_filter(net->can.rx_alldev_list, skb);
 
 	/* find receive list for this device */
-	d = find_dev_rcv_lists(net, dev);
-	if (d)
-		matches += can_rcv_filter(d, skb);
+	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
+	matches += can_rcv_filter(dev_rcv_lists, skb);
 
 	rcu_read_unlock();
 
···
 	consume_skb(skb);
 
 	if (matches > 0) {
-		can_stats->matches++;
-		can_stats->matches_delta++;
+		pkg_stats->matches++;
+		pkg_stats->matches_delta++;
 	}
 }
 
···
 			void *ptr)
 {
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-	struct can_dev_rcv_lists *d;
 
 	if (dev->type != ARPHRD_CAN)
 		return NOTIFY_DONE;
 
 	switch (msg) {
 	case NETDEV_REGISTER:
-
-		/* create new dev_rcv_lists for this device */
-		d = kzalloc(sizeof(*d), GFP_KERNEL);
-		if (!d)
-			return NOTIFY_DONE;
-		BUG_ON(dev->ml_priv);
-		dev->ml_priv = d;
-
-		break;
-
-	case NETDEV_UNREGISTER:
-		spin_lock(&dev_net(dev)->can.can_rcvlists_lock);
-
-		d = dev->ml_priv;
-		if (d) {
-			if (d->entries) {
-				d->remove_on_zero_entries = 1;
-			} else {
-				kfree(d);
-				dev->ml_priv = NULL;
-			}
-		} else {
-			pr_err("can: notifier: receive list not found for dev %s\n",
-			       dev->name);
-		}
-
-		spin_unlock(&dev_net(dev)->can.can_rcvlists_lock);
-
+		WARN(!dev->ml_priv,
+		     "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n");
 		break;
 	}
 
···
 
 static int can_pernet_init(struct net *net)
 {
-	spin_lock_init(&net->can.can_rcvlists_lock);
-	net->can.can_rx_alldev_list =
-		kzalloc(sizeof(*net->can.can_rx_alldev_list), GFP_KERNEL);
-	if (!net->can.can_rx_alldev_list)
+	spin_lock_init(&net->can.rcvlists_lock);
+	net->can.rx_alldev_list =
+		kzalloc(sizeof(*net->can.rx_alldev_list), GFP_KERNEL);
+	if (!net->can.rx_alldev_list)
 		goto out;
-	net->can.can_stats = kzalloc(sizeof(*net->can.can_stats), GFP_KERNEL);
-	if (!net->can.can_stats)
-		goto out_free_alldev_list;
-	net->can.can_pstats = kzalloc(sizeof(*net->can.can_pstats), GFP_KERNEL);
-	if (!net->can.can_pstats)
-		goto out_free_can_stats;
+	net->can.pkg_stats = kzalloc(sizeof(*net->can.pkg_stats), GFP_KERNEL);
+	if (!net->can.pkg_stats)
+		goto out_free_rx_alldev_list;
+	net->can.rcv_lists_stats = kzalloc(sizeof(*net->can.rcv_lists_stats), GFP_KERNEL);
+	if (!net->can.rcv_lists_stats)
+		goto out_free_pkg_stats;
 
 	if (IS_ENABLED(CONFIG_PROC_FS)) {
 		/* the statistics are updated every second (timer triggered) */
 		if (stats_timer) {
-			timer_setup(&net->can.can_stattimer, can_stat_update,
+			timer_setup(&net->can.stattimer, can_stat_update,
 				    0);
-			mod_timer(&net->can.can_stattimer,
+			mod_timer(&net->can.stattimer,
 				  round_jiffies(jiffies + HZ));
 		}
-		net->can.can_stats->jiffies_init = jiffies;
+		net->can.pkg_stats->jiffies_init = jiffies;
 		can_init_proc(net);
 	}
 
 	return 0;
 
- out_free_can_stats:
-	kfree(net->can.can_stats);
- out_free_alldev_list:
-	kfree(net->can.can_rx_alldev_list);
+ out_free_pkg_stats:
+	kfree(net->can.pkg_stats);
+ out_free_rx_alldev_list:
+	kfree(net->can.rx_alldev_list);
  out:
 	return -ENOMEM;
 }
 
 static void can_pernet_exit(struct net *net)
 {
-	struct net_device *dev;
-
 	if (IS_ENABLED(CONFIG_PROC_FS)) {
 		can_remove_proc(net);
 		if (stats_timer)
-			del_timer_sync(&net->can.can_stattimer);
+			del_timer_sync(&net->can.stattimer);
 	}
 
-	/* remove created dev_rcv_lists from still registered CAN devices */
-	rcu_read_lock();
-	for_each_netdev_rcu(net, dev) {
-		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
-			struct can_dev_rcv_lists *d = dev->ml_priv;
-
-			BUG_ON(d->entries);
-			kfree(d);
-			dev->ml_priv = NULL;
-		}
-	}
-	rcu_read_unlock();
-
-	kfree(net->can.can_rx_alldev_list);
-	kfree(net->can.can_stats);
-	kfree(net->can.can_pstats);
+	kfree(net->can.rx_alldev_list);
+	kfree(net->can.pkg_stats);
+	kfree(net->can.rcv_lists_stats);
 }
 
 /* af_can module init/exit functions */

net/can/af_can.h

···
 	struct rcu_head rcu;
 };
 
-#define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS)
-#define CAN_EFF_RCV_HASH_BITS 10
-#define CAN_EFF_RCV_ARRAY_SZ (1 << CAN_EFF_RCV_HASH_BITS)
-
-enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_MAX };
-
-/* per device receive filters linked at dev->ml_priv */
-struct can_dev_rcv_lists {
-	struct hlist_head rx[RX_MAX];
-	struct hlist_head rx_sff[CAN_SFF_RCV_ARRAY_SZ];
-	struct hlist_head rx_eff[CAN_EFF_RCV_ARRAY_SZ];
-	int remove_on_zero_entries;
-	int entries;
-};
-
 /* statistic structures */
 
 /* can be reset e.g. by can_init_stats() */
-struct s_stats {
+struct can_pkg_stats {
 	unsigned long jiffies_init;
 
 	unsigned long rx_frames;
···
 };
 
 /* persistent statistics */
-struct s_pstats {
+struct can_rcv_lists_stats {
 	unsigned long stats_reset;
 	unsigned long user_reset;
 	unsigned long rcv_entries;

net/can/bcm.c

···
 		/* no bound device as default => check msg_name */
 		DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
 
-		if (msg->msg_namelen < sizeof(*addr))
+		if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex))
 			return -EINVAL;
 
 		if (addr->can_family != AF_CAN)
···
 	struct net *net = sock_net(sk);
 	int ret = 0;
 
-	if (len < sizeof(*addr))
+	if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex))
 		return -EINVAL;
 
 	lock_sock(sk);

net/can/j1939/Kconfig

···
+# SPDX-License-Identifier: GPL-2.0
+#
+# SAE J1939 network layer core configuration
+#
+
+config CAN_J1939
+	tristate "SAE J1939"
+	depends on CAN
+	help
+	  SAE J1939
+	  Say Y to have in-kernel support for j1939 socket type. This
+	  allows communication according to SAE j1939.
+	  The relevant parts in kernel are
+	  SAE j1939-21 (datalink & transport protocol)
+	  & SAE j1939-81 (network management).

net/can/j1939/Makefile

···
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_CAN_J1939) += can-j1939.o
+
+can-j1939-objs := \
+	address-claim.o \
+	bus.o \
+	main.o \
+	socket.o \
+	transport.o

net/can/j1939/address-claim.c

···
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <[e-mail]>
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Pieter Beyens <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <[e-mail]>
+
+/* J1939 Address Claiming.
+ * Address Claiming in the kernel
+ * - keeps track of the AC states of ECU's,
+ * - resolves NAME<=>SA taking into account the AC states of ECU's.
+ *
+ * All Address Claim msgs (including host-originated msg) are processed
+ * at the receive path (a sent msg is always received again via CAN echo).
+ * As such, the processing of AC msgs is done in the order on which msgs
+ * are sent on the bus.
+ *
+ * This module doesn't send msgs itself (e.g. replies on Address Claims),
+ * this is the responsibility of a user space application or daemon.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+
+#include "j1939-priv.h"
+
+static inline name_t j1939_skb_to_name(const struct sk_buff *skb)
+{
+	return le64_to_cpup((__le64 *)skb->data);
+}
+
+static inline bool j1939_ac_msg_is_request(struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	int req_pgn;
+
+	if (skb->len < 3 || skcb->addr.pgn != J1939_PGN_REQUEST)
+		return false;
+
+	req_pgn = skb->data[0] | (skb->data[1] << 8) | (skb->data[2] << 16);
+
+	return req_pgn == J1939_PGN_ADDRESS_CLAIMED;
+}
+
+static int j1939_ac_verify_outgoing(struct j1939_priv *priv,
+				    struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+
+	if (skb->len != 8) {
+		netdev_notice(priv->ndev, "tx address claim with dlc %i\n",
+			      skb->len);
+		return -EPROTO;
+	}
+
+	if (skcb->addr.src_name != j1939_skb_to_name(skb)) {
+		netdev_notice(priv->ndev, "tx address claim with different name\n");
+		return -EPROTO;
+	}
+
+	if (skcb->addr.sa == J1939_NO_ADDR) {
+		netdev_notice(priv->ndev, "tx address claim with broadcast sa\n");
+		return -EPROTO;
+	}
+
+	/* ac must always be a broadcast */
+	if (skcb->addr.dst_name || skcb->addr.da != J1939_NO_ADDR) {
+		netdev_notice(priv->ndev, "tx address claim with dest, not broadcast\n");
+		return -EPROTO;
+	}
+	return 0;
+}
+
+int j1939_ac_fixup(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	int ret;
+	u8 addr;
+
+	/* network mgmt: address claiming msgs */
+	if (skcb->addr.pgn == J1939_PGN_ADDRESS_CLAIMED) {
+		struct j1939_ecu *ecu;
+
+		ret = j1939_ac_verify_outgoing(priv, skb);
+		/* return both when failure & when successful */
+		if (ret < 0)
+			return ret;
+		ecu = j1939_ecu_get_by_name(priv, skcb->addr.src_name);
+		if (!ecu)
+			return -ENODEV;
+
+		if (ecu->addr != skcb->addr.sa)
+			/* hold further traffic for ecu, remove from parent */
+			j1939_ecu_unmap(ecu);
+		j1939_ecu_put(ecu);
+	} else if (skcb->addr.src_name) {
+		/* assign source address */
+		addr = j1939_name_to_addr(priv, skcb->addr.src_name);
+		if (!j1939_address_is_unicast(addr) &&
+		    !j1939_ac_msg_is_request(skb)) {
+			netdev_notice(priv->ndev, "tx drop: invalid sa for name 0x%016llx\n",
+				      skcb->addr.src_name);
+			return -EADDRNOTAVAIL;
+		}
+		skcb->addr.sa = addr;
+	}
+
+	/* assign destination address */
+	if (skcb->addr.dst_name) {
+		addr = j1939_name_to_addr(priv, skcb->addr.dst_name);
+		if (!j1939_address_is_unicast(addr)) {
+			netdev_notice(priv->ndev, "tx drop: invalid da for name 0x%016llx\n",
+				      skcb->addr.dst_name);
+			return -EADDRNOTAVAIL;
+		}
+		skcb->addr.da = addr;
+	}
+	return 0;
+}
+
+static void j1939_ac_process(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_ecu *ecu, *prev;
+	name_t name;
+
+	if (skb->len != 8) {
+		netdev_notice(priv->ndev, "rx address claim with wrong dlc %i\n",
+			      skb->len);
+		return;
+	}
+
+	name = j1939_skb_to_name(skb);
+	skcb->addr.src_name = name;
+	if (!name) {
+		netdev_notice(priv->ndev, "rx address claim without name\n");
+		return;
+	}
+
+	if (!j1939_address_is_valid(skcb->addr.sa)) {
+		netdev_notice(priv->ndev, "rx address claim with broadcast sa\n");
+		return;
+	}
+
+	write_lock_bh(&priv->lock);
+
+	/* Few words on the ECU ref counting:
+	 *
+	 * First we get an ECU handle, either with
+	 * j1939_ecu_get_by_name_locked() (increments the ref counter)
+	 * or j1939_ecu_create_locked() (initializes an ECU object
+	 * with a ref counter of 1).
+	 *
+	 * j1939_ecu_unmap_locked() will decrement the ref counter,
+	 * but only if the ECU was mapped before. So "ecu" still
+	 * belongs to us.
+	 *
+	 * j1939_ecu_timer_start() will increment the ref counter
+	 * before it starts the timer, so we can put the ecu when
+	 * leaving this function.
+	 */
+	ecu = j1939_ecu_get_by_name_locked(priv, name);
+	if (!ecu && j1939_address_is_unicast(skcb->addr.sa))
+		ecu = j1939_ecu_create_locked(priv, name);
+
+	if (IS_ERR_OR_NULL(ecu))
+		goto out_unlock_bh;
+
+	/* cancel pending (previous) address claim */
+	j1939_ecu_timer_cancel(ecu);
+
+	if (j1939_address_is_idle(skcb->addr.sa)) {
+		j1939_ecu_unmap_locked(ecu);
+		goto out_ecu_put;
+	}
+
+	/* save new addr */
+	if (ecu->addr != skcb->addr.sa)
+		j1939_ecu_unmap_locked(ecu);
+	ecu->addr = skcb->addr.sa;
+
+	prev = j1939_ecu_get_by_addr_locked(priv, skcb->addr.sa);
+	if (prev) {
+		if (ecu->name > prev->name) {
+			j1939_ecu_unmap_locked(ecu);
+			j1939_ecu_put(prev);
+			goto out_ecu_put;
+		} else {
+			/* kick prev if less or equal */
+			j1939_ecu_unmap_locked(prev);
+			j1939_ecu_put(prev);
+		}
+	}
+
+	j1939_ecu_timer_start(ecu);
+ out_ecu_put:
+	j1939_ecu_put(ecu);
+ out_unlock_bh:
+	write_unlock_bh(&priv->lock);
+}
+
+void j1939_ac_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_ecu *ecu;
+
+	/* network mgmt */
+	if (skcb->addr.pgn == J1939_PGN_ADDRESS_CLAIMED) {
+		j1939_ac_process(priv, skb);
+	} else if (j1939_address_is_unicast(skcb->addr.sa)) {
+		/* assign source name */
+		ecu = j1939_ecu_get_by_addr(priv, skcb->addr.sa);
+		if (ecu) {
+			skcb->addr.src_name = ecu->name;
+			j1939_ecu_put(ecu);
+		}
+	}
+
+	/* assign destination name */
+	ecu = j1939_ecu_get_by_addr(priv, skcb->addr.da);
+	if (ecu) {
+		skcb->addr.dst_name = ecu->name;
+		j1939_ecu_put(ecu);
+	}
+}

net/can/j1939/bus.c

···
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <[e-mail]>
+
+/* bus for j1939 remote devices
+ * Since rtnetlink, no real bus is used.
+ */
+
+#include <net/sock.h>
+
+#include "j1939-priv.h"
+
+static void __j1939_ecu_release(struct kref *kref)
+{
+	struct j1939_ecu *ecu = container_of(kref, struct j1939_ecu, kref);
+	struct j1939_priv *priv = ecu->priv;
+
+	list_del(&ecu->list);
+	kfree(ecu);
+	j1939_priv_put(priv);
+}
+
+void j1939_ecu_put(struct j1939_ecu *ecu)
+{
+	kref_put(&ecu->kref, __j1939_ecu_release);
+}
+
+static void j1939_ecu_get(struct j1939_ecu *ecu)
+{
+	kref_get(&ecu->kref);
+}
+
+static bool j1939_ecu_is_mapped_locked(struct j1939_ecu *ecu)
+{
+	struct j1939_priv *priv = ecu->priv;
+
+	lockdep_assert_held(&priv->lock);
+
+	return j1939_ecu_find_by_addr_locked(priv, ecu->addr) == ecu;
+}
+
+/* ECU device interface */
+/* map ECU to a bus address space */
+static void j1939_ecu_map_locked(struct j1939_ecu *ecu)
+{
+	struct j1939_priv *priv = ecu->priv;
+	struct j1939_addr_ent *ent;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!j1939_address_is_unicast(ecu->addr))
+		return;
+
+	ent = &priv->ents[ecu->addr];
+
+	if (ent->ecu) {
+		netdev_warn(priv->ndev, "Trying to map already mapped ECU, addr: 0x%02x, name: 0x%016llx. Skip it.\n",
+			    ecu->addr, ecu->name);
+		return;
+	}
+
+	j1939_ecu_get(ecu);
+	ent->ecu = ecu;
+	ent->nusers += ecu->nusers;
+}
+
+/* unmap ECU from a bus address space */
+void j1939_ecu_unmap_locked(struct j1939_ecu *ecu)
+{
+	struct j1939_priv *priv = ecu->priv;
+	struct j1939_addr_ent *ent;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!j1939_address_is_unicast(ecu->addr))
+		return;
+
+	if (!j1939_ecu_is_mapped_locked(ecu))
+		return;
+
+	ent = &priv->ents[ecu->addr];
+	ent->ecu = NULL;
+	ent->nusers -= ecu->nusers;
+	j1939_ecu_put(ecu);
+}
+
+void j1939_ecu_unmap(struct j1939_ecu *ecu)
+{
+	write_lock_bh(&ecu->priv->lock);
+	j1939_ecu_unmap_locked(ecu);
+	write_unlock_bh(&ecu->priv->lock);
+}
+
+void j1939_ecu_unmap_all(struct j1939_priv *priv)
+{
+	int i;
+
+	write_lock_bh(&priv->lock);
+	for (i = 0; i < ARRAY_SIZE(priv->ents); i++)
+		if (priv->ents[i].ecu)
+			j1939_ecu_unmap_locked(priv->ents[i].ecu);
+	write_unlock_bh(&priv->lock);
+}
+
+void j1939_ecu_timer_start(struct j1939_ecu *ecu)
+{
+	/* The ECU is held here and released in the
+	 * j1939_ecu_timer_handler() or j1939_ecu_timer_cancel().
+	 */
+	j1939_ecu_get(ecu);
+
+	/* Schedule timer in 250 msec to commit address change. */
+	hrtimer_start(&ecu->ac_timer, ms_to_ktime(250),
+		      HRTIMER_MODE_REL_SOFT);
+}
+
+void j1939_ecu_timer_cancel(struct j1939_ecu *ecu)
+{
+	if (hrtimer_cancel(&ecu->ac_timer))
+		j1939_ecu_put(ecu);
+}
+
+static enum hrtimer_restart j1939_ecu_timer_handler(struct hrtimer *hrtimer)
+{
+	struct j1939_ecu *ecu =
+		container_of(hrtimer, struct j1939_ecu, ac_timer);
+	struct j1939_priv *priv = ecu->priv;
+
+	write_lock_bh(&priv->lock);
+	/* TODO: can we test if ecu->addr is unicast before starting
+	 * the timer?
+	 */
+	j1939_ecu_map_locked(ecu);
+
+	/* The corresponding j1939_ecu_get() is in
+	 * j1939_ecu_timer_start().
+	 */
+	j1939_ecu_put(ecu);
+	write_unlock_bh(&priv->lock);
+
+	return HRTIMER_NORESTART;
+}
+
+struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	ecu = kzalloc(sizeof(*ecu), gfp_any());
+	if (!ecu)
+		return ERR_PTR(-ENOMEM);
+	kref_init(&ecu->kref);
+	ecu->addr = J1939_IDLE_ADDR;
+	ecu->name = name;
+
+	hrtimer_init(&ecu->ac_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+	ecu->ac_timer.function = j1939_ecu_timer_handler;
+	INIT_LIST_HEAD(&ecu->list);
+
+	j1939_priv_get(priv);
+	ecu->priv = priv;
+	list_add_tail(&ecu->list, &priv->ecus);
+
+	return ecu;
+}
+
+struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv,
+						u8 addr)
+{
+	lockdep_assert_held(&priv->lock);
+
+	return priv->ents[addr].ecu;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv, u8 addr)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!j1939_address_is_unicast(addr))
+		return NULL;
+
+	ecu = j1939_ecu_find_by_addr_locked(priv, addr);
+	if (ecu)
+		j1939_ecu_get(ecu);
+
+	return ecu;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr)
+{
+	struct j1939_ecu *ecu;
+
+	read_lock_bh(&priv->lock);
+	ecu = j1939_ecu_get_by_addr_locked(priv, addr);
+	read_unlock_bh(&priv->lock);
+
+	return ecu;
+}
+
+/* get pointer to ecu without increasing ref counter */
+static struct j1939_ecu *j1939_ecu_find_by_name_locked(struct j1939_priv *priv,
+						       name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	list_for_each_entry(ecu, &priv->ecus, list) {
+		if (ecu->name == name)
+			return ecu;
+	}
+
+	return NULL;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv,
+					       name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!name)
+		return NULL;
+
+	ecu = j1939_ecu_find_by_name_locked(priv, name);
+	if (ecu)
+		j1939_ecu_get(ecu);
+
+	return ecu;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	read_lock_bh(&priv->lock);
+	ecu = j1939_ecu_get_by_name_locked(priv, name);
+	read_unlock_bh(&priv->lock);
+
+	return ecu;
+}
+
+u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name)
+{
+	struct j1939_ecu *ecu;
+	int addr = J1939_IDLE_ADDR;
+
+	if (!name)
+		return J1939_NO_ADDR;
+
+	read_lock_bh(&priv->lock);
+	ecu = j1939_ecu_find_by_name_locked(priv, name);
+	if (ecu && j1939_ecu_is_mapped_locked(ecu))
+		/* ecu's SA is registered */
+		addr = ecu->addr;
+
+	read_unlock_bh(&priv->lock);
+
+	return addr;
+}
+
+/* TX addr/name accounting
+ * Transport protocol needs to know if a SA is local or not
+ * These functions originate from userspace manipulating sockets,
+ * so locking is straigforward
+ */
+
+int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa)
+{
+	struct j1939_ecu *ecu;
+	int err = 0;
+
+	write_lock_bh(&priv->lock);
+
+	if (j1939_address_is_unicast(sa))
+		priv->ents[sa].nusers++;
+
+	if (!name)
+		goto done;
+
+	ecu = j1939_ecu_get_by_name_locked(priv, name);
+	if (!ecu)
+		ecu = j1939_ecu_create_locked(priv, name);
+	err = PTR_ERR_OR_ZERO(ecu);
+	if (err)
+		goto done;
+
+	ecu->nusers++;
+	/* TODO: do we care if ecu->addr != sa? */
+	if (j1939_ecu_is_mapped_locked(ecu))
+		/* ecu's sa is active already */
+		priv->ents[ecu->addr].nusers++;
+
+ done:
+	write_unlock_bh(&priv->lock);
+
+	return err;
+}
+
+void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa)
+{
+	struct j1939_ecu *ecu;
+
+	write_lock_bh(&priv->lock);
+
+	if (j1939_address_is_unicast(sa))
+		priv->ents[sa].nusers--;
+
+	if (!name)
+		goto done;
+
+	ecu = j1939_ecu_find_by_name_locked(priv, name);
+	if (WARN_ON_ONCE(!ecu))
+		goto done;
+
+	ecu->nusers--;
+	/* TODO: do we care if ecu->addr != sa? */
+	if (j1939_ecu_is_mapped_locked(ecu))
+		/* ecu's sa is active already */
+		priv->ents[ecu->addr].nusers--;
+	j1939_ecu_put(ecu);
+
+ done:
+	write_unlock_bh(&priv->lock);
+}

net/can/j1939/j1939-priv.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <[e-mail]>
+
+#ifndef _J1939_PRIV_H_
+#define _J1939_PRIV_H_
+
+#include <linux/can/j1939.h>
+#include <net/sock.h>
+
+/* Timeout to receive the abort signal over loop back. In case CAN
+ * bus is open, the timeout should be triggered.
+ */
+#define J1939_XTP_ABORT_TIMEOUT_MS 500
+#define J1939_SIMPLE_ECHO_TIMEOUT_MS (10 * 1000)
+
+struct j1939_session;
+enum j1939_sk_errqueue_type {
+	J1939_ERRQUEUE_ACK,
+	J1939_ERRQUEUE_SCHED,
+	J1939_ERRQUEUE_ABORT,
+};
+
+/* j1939 devices */
+struct j1939_ecu {
+	struct list_head list;
+	name_t name;
+	u8 addr;
+
+	/* indicates that this ecu successfully claimed @sa as its address */
+	struct hrtimer ac_timer;
+	struct kref kref;
+	struct j1939_priv *priv;
+
+	/* count users, to help transport protocol decide for interaction */
+	int nusers;
+};
+
+struct j1939_priv {
+	struct list_head ecus;
+	/* local list entry in priv
+	 * These allow irq (& softirq) context lookups on j1939 devices
+	 * This approach (separate lists) is done as the other 2 alternatives
+	 * are not easier or even wrong
+	 * 1) using the pure kobject methods involves mutexes, which are not
+	 *    allowed in irq context.
+	 * 2) duplicating data structures would require a lot of synchronization
+	 *    code
+	 * usage:
+	 */
+
+	/* segments need a lock to protect the above list */
+	rwlock_t lock;
+
+	struct net_device *ndev;
+
+	/* list of 256 ecu ptrs, that cache the claimed addresses.
+	 * also protected by the above lock
+	 */
+	struct j1939_addr_ent {
+		struct j1939_ecu *ecu;
+		/* count users, to help transport protocol */
+		int nusers;
+	} ents[256];
+
+	struct kref kref;
+
+	/* List of active sessions to prevent start of conflicting
+	 * one.
+	 *
+	 * Do not start two sessions of same type, addresses and
+	 * direction.
+	 */
+	struct list_head active_session_list;
+
+	/* protects active_session_list */
+	spinlock_t active_session_list_lock;
+
+	unsigned int tp_max_packet_size;
+
+	/* lock for j1939_socks list */
+	spinlock_t j1939_socks_lock;
+	struct list_head j1939_socks;
+
+	struct kref rx_kref;
+};
+
+void j1939_ecu_put(struct j1939_ecu *ecu);
+
+/* keep the cache of what is local */
+int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa);
+void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa);
+
+static inline bool j1939_address_is_unicast(u8 addr)
+{
+	return addr <= J1939_MAX_UNICAST_ADDR;
+}
+
+static inline bool j1939_address_is_idle(u8 addr)
+{
+	return addr == J1939_IDLE_ADDR;
+}
+
+static inline bool j1939_address_is_valid(u8 addr)
+{
+	return addr != J1939_NO_ADDR;
+}
+
+static inline bool j1939_pgn_is_pdu1(pgn_t pgn)
+{
+	/* ignore dp & res bits for this */
+	return (pgn & 0xff00) < 0xf000;
+}
+
+/* utility to correctly unmap an ECU */
+void j1939_ecu_unmap_locked(struct j1939_ecu *ecu);
+void j1939_ecu_unmap(struct j1939_ecu *ecu);
+
+u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name);
+struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv,
+						u8 addr);
+struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr);
+struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv,
+					       u8 addr);
+struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name);
+struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv,
+					       name_t name);
+
+enum j1939_transfer_type {
+	J1939_TP,
+	J1939_ETP,
+	J1939_SIMPLE,
+};
+
+struct j1939_addr {
+	name_t src_name;
+	name_t dst_name;
+	pgn_t pgn;
+
+	u8 sa;
+	u8 da;
+
+	u8 type;
+};
+
+/* control buffer of the sk_buff */
+struct j1939_sk_buff_cb {
+	/* Offset in bytes within one ETP session */
+	u32 offset;
+
+	/* for tx, MSG_SYN will be used to sync on sockets */
+	u32 msg_flags;
+	u32 tskey;
+
+	struct j1939_addr addr;
+
+	/* Flags for quick lookups during skb processing.
+	 * These are set in the receive path only.
+	 */
+#define J1939_ECU_LOCAL_SRC BIT(0)
+#define J1939_ECU_LOCAL_DST BIT(1)
+	u8 flags;
+
+	priority_t priority;
+};
+
+static inline
+struct j1939_sk_buff_cb *j1939_skb_to_cb(const struct sk_buff *skb)
+{
+	BUILD_BUG_ON(sizeof(struct j1939_sk_buff_cb) > sizeof(skb->cb));
+
+	return (struct j1939_sk_buff_cb *)skb->cb;
+}
+
+int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb);
+void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb);
+bool j1939_sk_recv_match(struct j1939_priv *priv,
+			 struct j1939_sk_buff_cb *skcb);
+void j1939_sk_send_loop_abort(struct sock *sk, int err);
+void j1939_sk_errqueue(struct j1939_session *session,
+		       enum j1939_sk_errqueue_type type);
+void j1939_sk_queue_activate_next(struct j1939_session *session);
+
+/* stack entries */
+struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
+				    struct sk_buff *skb, size_t size);
+int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb);
+int j1939_ac_fixup(struct j1939_priv *priv, struct sk_buff *skb);
+void j1939_ac_recv(struct j1939_priv *priv, struct sk_buff *skb);
+void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb);
+
+/* network management */
+struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name);
+
+void j1939_ecu_timer_start(struct j1939_ecu *ecu);
+void j1939_ecu_timer_cancel(struct j1939_ecu *ecu);
+void j1939_ecu_unmap_all(struct j1939_priv *priv);
+
+struct j1939_priv *j1939_netdev_start(struct net_device *ndev);
+void j1939_netdev_stop(struct j1939_priv *priv);
+
+void j1939_priv_put(struct j1939_priv *priv);
+void j1939_priv_get(struct j1939_priv *priv);
+
+/* notify/alert all j1939 sockets bound to ifindex */
+void j1939_sk_netdev_event_netdown(struct j1939_priv *priv);
+int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk);
+void j1939_tp_init(struct j1939_priv *priv);
+
+/* decrement pending skb for a j1939 socket */
+void j1939_sock_pending_del(struct sock *sk);
+
+enum j1939_session_state {
+	J1939_SESSION_NEW,
+	J1939_SESSION_ACTIVE,
+	/* waiting for abort signal on the bus */
+	J1939_SESSION_WAITING_ABORT,
+	J1939_SESSION_ACTIVE_MAX,
+	J1939_SESSION_DONE,
+};
+
+struct j1939_session {
+	struct j1939_priv *priv;
+	struct list_head active_session_list_entry;
+	struct list_head sk_session_queue_entry;
+	struct kref kref;
+	struct sock *sk;
+
+	/* ifindex, src, dst, pgn define the session block
+	 * the are _never_ modified after insertion in the list
+	 * this decreases locking problems a _lot_
+	 */
+	struct j1939_sk_buff_cb skcb;
+	struct sk_buff_head skb_queue;
+
+	/* all tx related stuff (last_txcmd, pkt.tx)
+	 * is protected (modified only) with the txtimer hrtimer
+	 * 'total' & 'block' are never changed,
+	 * last_cmd, last & block are protected by ->lock
+	 * this means that the tx may run after cts is received that should
+	 * have stopped tx, but this time discrepancy is never avoided anyhow
+	 */
+	u8 last_cmd, last_txcmd;
+	bool transmission;
+	bool extd;
+	/* Total message size, number of bytes */
+	unsigned int total_message_size;
+	/* Total number of bytes queue from socket to the session */
+	unsigned int total_queued_size;
+	unsigned int tx_retry;
+
+	int err;
+	u32 tskey;
+	enum j1939_session_state state;
+
+	/* Packets counters for a (extended) transfer session. The packet is
+	 * maximal of 7 bytes.
+	 */
+	struct {
+		/* total - total number of packets for this session */
+		unsigned int total;
+		/* last - last packet of a transfer block after which
+		 * responder should send ETP.CM_CTS and originator
+		 * ETP.CM_DPO
+		 */
+		unsigned int last;
+		/* tx - number of packets send by originator node.
+		 * this counter can be set back if responder node
+		 * didn't received all packets send by originator.
+		 */
+		unsigned int tx;
+		unsigned int tx_acked;
+		/* rx - number of packets received */
+		unsigned int rx;
+		/* block - amount of packets expected in one block */
+		unsigned int block;
+		/* dpo - ETP.CM_DPO, Data Packet Offset */
+		unsigned int dpo;
+	} pkt;
+	struct hrtimer txtimer, rxtimer;
+};
+
+struct j1939_sock {
+	struct sock sk; /* must be first to skip with memset */
+	struct j1939_priv *priv;
+	struct list_head list;
+
+#define J1939_SOCK_BOUND BIT(0)
+#define J1939_SOCK_CONNECTED BIT(1)
+#define J1939_SOCK_PROMISC BIT(2)
+#define J1939_SOCK_ERRQUEUE BIT(3)
+	int state;
+
+	int ifindex;
+	struct j1939_addr addr;
+	struct j1939_filter *filters;
+	int nfilters;
+	pgn_t pgn_rx_filter;
+
+	/* j1939 may emit equal PGN (!= equal CAN-id's) out of order
+	 * when transport protocol comes in.
+	 * To allow emitting in order, keep a 'pending' nr. of packets
+	 */
+	atomic_t skb_pending;
+	wait_queue_head_t waitq;
+
+	/* lock for the sk_session_queue list */
+	spinlock_t sk_session_queue_lock;
+	struct list_head sk_session_queue;
+};
+
+static inline struct j1939_sock *j1939_sk(const struct sock *sk)
+{
+	return container_of(sk, struct j1939_sock, sk);
+}
+
+void j1939_session_get(struct j1939_session *session);
+void j1939_session_put(struct j1939_session *session);
+void j1939_session_skb_queue(struct j1939_session *session,
+			     struct sk_buff *skb);
+int j1939_session_activate(struct j1939_session *session);
+void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec);
+void j1939_session_timers_cancel(struct j1939_session *session);
+
+#define J1939_MAX_TP_PACKET_SIZE (7 * 0xff)
+#define J1939_MAX_ETP_PACKET_SIZE (7 * 0x00ffffff)
+
+#define J1939_REGULAR 0
+#define J1939_EXTENDED 1
+
+/* CAN protocol */
+extern const struct can_proto j1939_can_proto;
+
+#endif /* _J1939_PRIV_H_ */

net/can/j1939/main.c

···
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Pieter Beyens <[e-mail]>
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <[e-mail]>
+// Copyright (c) 2018 Protonic,
+//                         Robin van der Gracht <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <[e-mail]>
+
+/* Core of can-j1939 that links j1939 to CAN. */
+
+#include <linux/can/can-ml.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+
+#include "j1939-priv.h"
+
+MODULE_DESCRIPTION("PF_CAN SAE J1939");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("EIA Electronics (Kurt Van Dijck & Pieter Beyens)");
+MODULE_ALIAS("can-proto-" __stringify(CAN_J1939));
+
+/* LOWLEVEL CAN interface */
+
+/* CAN_HDR: #bytes before can_frame data part */
+#define J1939_CAN_HDR (offsetof(struct can_frame, data))
+
+/* CAN_FTR: #bytes beyond data part */
+#define J1939_CAN_FTR (sizeof(struct can_frame) - J1939_CAN_HDR - \
+		 sizeof(((struct can_frame *)0)->data))
+
+/* lowest layer */
+static void j1939_can_recv(struct sk_buff *iskb, void *data)
+{
+	struct j1939_priv *priv = data;
+	struct sk_buff *skb;
+	struct j1939_sk_buff_cb *skcb, *iskcb;
+	struct can_frame *cf;
+
+	/* create a copy of the skb
+	 * j1939 only delivers the real data bytes,
+	 * the header goes into sockaddr.
+	 * j1939 may not touch the incoming skb in such way
+	 */
+	skb = skb_clone(iskb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	can_skb_set_owner(skb, iskb->sk);
+
+	/* get a pointer to the header of the skb
+	 * the skb payload (pointer) is moved, so that the next skb_data
+	 * returns the actual payload
+	 */
+	cf = (void *)skb->data;
+	skb_pull(skb, J1939_CAN_HDR);
+
+	/* fix length, set to dlc, with 8 maximum */
+	skb_trim(skb, min_t(uint8_t, cf->can_dlc, 8));
+
+	/* set addr */
+	skcb = j1939_skb_to_cb(skb);
+	memset(skcb, 0, sizeof(*skcb));
+
+	iskcb = j1939_skb_to_cb(iskb);
+	skcb->tskey = iskcb->tskey;
+	skcb->priority = (cf->can_id >> 26) & 0x7;
+	skcb->addr.sa = cf->can_id;
+	skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
+	/* set default message type */
+	skcb->addr.type = J1939_TP;
+	if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
+		/* Type 1: with destination address */
+		skcb->addr.da = skcb->addr.pgn;
+		/* normalize pgn: strip dst address */
+		skcb->addr.pgn &= 0x3ff00;
+	} else {
+		/* set broadcast address */
+		skcb->addr.da = J1939_NO_ADDR;
+	}
+
+	/* update localflags */
+	read_lock_bh(&priv->lock);
+	if (j1939_address_is_unicast(skcb->addr.sa) &&
+	    priv->ents[skcb->addr.sa].nusers)
+		skcb->flags |= J1939_ECU_LOCAL_SRC;
+	if (j1939_address_is_unicast(skcb->addr.da) &&
+	    priv->ents[skcb->addr.da].nusers)
+		skcb->flags |= J1939_ECU_LOCAL_DST;
+	read_unlock_bh(&priv->lock);
+
+	/* deliver into the j1939 stack ... */
+	j1939_ac_recv(priv, skb);
+
+	if (j1939_tp_recv(priv, skb))
+		/* this means the transport layer processed the message */
+		goto done;
+
+	j1939_simple_recv(priv, skb);
+	j1939_sk_recv(priv, skb);
+ done:
+	kfree_skb(skb);
+}
+
+/* NETDEV MANAGEMENT */
+
+/* values for can_rx_(un)register */
+#define J1939_CAN_ID CAN_EFF_FLAG
+#define J1939_CAN_MASK (CAN_EFF_FLAG | CAN_RTR_FLAG)
+
+static DEFINE_SPINLOCK(j1939_netdev_lock);
+
+static struct j1939_priv *j1939_priv_create(struct net_device *ndev)
+{
+	struct j1939_priv *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return NULL;
+
+	rwlock_init(&priv->lock);
+	INIT_LIST_HEAD(&priv->ecus);
+	priv->ndev = ndev;
+	kref_init(&priv->kref);
+	kref_init(&priv->rx_kref);
+	dev_hold(ndev);
+
+	netdev_dbg(priv->ndev, "%s : 0x%p\n", __func__, priv);
+
+	return priv;
+}
+
+static inline void j1939_priv_set(struct net_device *ndev,
+				  struct j1939_priv *priv)
+{
+	struct can_ml_priv *can_ml_priv = ndev->ml_priv;
+
+	can_ml_priv->j1939_priv = priv;
+}
+
+static void __j1939_priv_release(struct kref *kref)
+{
+	struct j1939_priv *priv = container_of(kref, struct j1939_priv, kref);
+	struct net_device *ndev = priv->ndev;
+
+	netdev_dbg(priv->ndev, "%s: 0x%p\n", __func__, priv);
+
+	dev_put(ndev);
+	kfree(priv);
+}
+
+void j1939_priv_put(struct j1939_priv *priv)
+{
+	kref_put(&priv->kref, __j1939_priv_release);
+}
+
+void j1939_priv_get(struct j1939_priv *priv)
+{
+	kref_get(&priv->kref);
+}
+
+static int j1939_can_rx_register(struct j1939_priv *priv)
+{
+	struct net_device *ndev = priv->ndev;
+	int ret;
+
+	j1939_priv_get(priv);
+	ret = can_rx_register(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
+			      j1939_can_recv, priv, "j1939", NULL);
+	if (ret < 0) {
+		j1939_priv_put(priv);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void j1939_can_rx_unregister(struct j1939_priv *priv)
+{
+	struct net_device *ndev = priv->ndev;
+
+	can_rx_unregister(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
+			  j1939_can_recv, priv);
+
+	j1939_priv_put(priv);
+}
+
+static void __j1939_rx_release(struct kref *kref)
+	__releases(&j1939_netdev_lock)
+{
+	struct j1939_priv *priv = container_of(kref, struct j1939_priv,
+					       rx_kref);
+
+	j1939_can_rx_unregister(priv);
+	j1939_ecu_unmap_all(priv);
+	j1939_priv_set(priv->ndev, NULL);
+	spin_unlock(&j1939_netdev_lock);
+}
+
+/* get pointer to priv without increasing ref counter */
+static inline struct j1939_priv *j1939_ndev_to_priv(struct net_device *ndev)
+{
+	struct can_ml_priv *can_ml_priv = ndev->ml_priv;
+
+	return can_ml_priv->j1939_priv;
+}
+
+static struct j1939_priv *j1939_priv_get_by_ndev_locked(struct net_device *ndev)
+{
+	struct j1939_priv *priv;
+
+	lockdep_assert_held(&j1939_netdev_lock);
+
+	if (ndev->type != ARPHRD_CAN)
+		return NULL;
+
+	priv = j1939_ndev_to_priv(ndev);
+	if (priv)
+		j1939_priv_get(priv);
+
+	return priv;
+}
+
+static struct j1939_priv *j1939_priv_get_by_ndev(struct net_device *ndev)
+{
+	struct j1939_priv *priv;
+
+	spin_lock(&j1939_netdev_lock);
+	priv = j1939_priv_get_by_ndev_locked(ndev);
+	spin_unlock(&j1939_netdev_lock);
+
+	return priv;
+}
+
+struct j1939_priv *j1939_netdev_start(struct net_device *ndev)
+{
+	struct j1939_priv *priv, *priv_new;
+	int ret;
+
+	priv = j1939_priv_get_by_ndev(ndev);
+	if (priv) {
+		kref_get(&priv->rx_kref);
+		return priv;
+	}
+
+	priv = j1939_priv_create(ndev);
+	if (!priv)
+		return ERR_PTR(-ENOMEM);
+
+	j1939_tp_init(priv);
+	spin_lock_init(&priv->j1939_socks_lock);
+	INIT_LIST_HEAD(&priv->j1939_socks);
+
+	spin_lock(&j1939_netdev_lock);
+	priv_new = j1939_priv_get_by_ndev_locked(ndev);
+	if (priv_new) {
+		/* Someone was faster than us, use their priv and roll
+		 * back our's.
+		 */
+		spin_unlock(&j1939_netdev_lock);
+		dev_put(ndev);
+		kfree(priv);
+		kref_get(&priv_new->rx_kref);
+		return priv_new;
+	}
+	j1939_priv_set(ndev, priv);
+	spin_unlock(&j1939_netdev_lock);
+
+	ret = j1939_can_rx_register(priv);
+	if (ret < 0)
+		goto out_priv_put;
+
+	return priv;
+
+ out_priv_put:
+	j1939_priv_set(ndev, NULL);
+	dev_put(ndev);
+	kfree(priv);
+
+	return ERR_PTR(ret);
+}
+
+void j1939_netdev_stop(struct j1939_priv *priv)
+{
+	kref_put_lock(&priv->rx_kref, __j1939_rx_release, &j1939_netdev_lock);
+	j1939_priv_put(priv);
+}
+
+int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	int ret, dlc;
+	canid_t canid;
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct can_frame *cf;
+
+	/* apply sanity checks */
+	if (j1939_pgn_is_pdu1(skcb->addr.pgn))
+		skcb->addr.pgn &= J1939_PGN_PDU1_MAX;
+	else
+		skcb->addr.pgn &= J1939_PGN_MAX;
+
+	if (skcb->priority > 7)
+		skcb->priority = 6;
+
+	ret = j1939_ac_fixup(priv, skb);
+	if (unlikely(ret))
+		goto failed;
+	dlc = skb->len;
+
+	/* re-claim the CAN_HDR from the SKB */
+	cf = skb_push(skb, J1939_CAN_HDR);
+
+	/* make it a full can frame again */
+	skb_put(skb, J1939_CAN_FTR + (8 - dlc));
+
+	canid = CAN_EFF_FLAG |
+		(skcb->priority << 26) |
+		(skcb->addr.pgn << 8) |
+		skcb->addr.sa;
+	if (j1939_pgn_is_pdu1(skcb->addr.pgn))
+		canid |= skcb->addr.da << 8;
+
+	cf->can_id = canid;
+	cf->can_dlc = dlc;
+
+	return can_send(skb, 1);
+
+ failed:
+	kfree_skb(skb);
+	return ret;
+}
+
+static int j1939_netdev_notify(struct notifier_block *nb,
+			       unsigned long msg, void *data)
+{
+	struct net_device *ndev = netdev_notifier_info_to_dev(data);
+	struct j1939_priv *priv;
+
+	priv = j1939_priv_get_by_ndev(ndev);
+	if (!priv)
+		goto notify_done;
+
+	if (ndev->type != ARPHRD_CAN)
+		goto notify_put;
+
+	switch (msg) {
+	case NETDEV_DOWN:
+		j1939_cancel_active_session(priv, NULL);
+		j1939_sk_netdev_event_netdown(priv);
+		j1939_ecu_unmap_all(priv);
+		break;
+	}
+
+notify_put:
+	j1939_priv_put(priv);
+
+notify_done:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block j1939_netdev_notifier = {
+	.notifier_call = j1939_netdev_notify,
+};
+
+/* MODULE interface */
+static __init int j1939_module_init(void)
+{
+	int ret;
+
+	pr_info("can: SAE J1939\n");
+
+	ret = register_netdevice_notifier(&j1939_netdev_notifier);
+	if (ret)
+		goto fail_notifier;
+
+	ret = can_proto_register(&j1939_can_proto);
+	if (ret < 0) {
+		pr_err("can: registration of j1939 protocol failed\n");
+		goto fail_sk;
+	}
+
+	return 0;
+
+ fail_sk:
+	unregister_netdevice_notifier(&j1939_netdev_notifier);
+ fail_notifier:
+	return ret;
+}
+
+static __exit void j1939_module_exit(void)
+{
+	can_proto_unregister(&j1939_can_proto);
+
+	unregister_netdevice_notifier(&j1939_netdev_notifier);
+}
+
+module_init(j1939_module_init);
+module_exit(j1939_module_exit);

net/can/j1939/socket.c

···
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Pieter Beyens <[e-mail]>
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <[e-mail]>
+// Copyright (c) 2018 Protonic,
+//                         Robin van der Gracht <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <[e-mail]>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/errqueue.h>
+#include <linux/if_arp.h>
+
+#include "j1939-priv.h"
+
+#define J1939_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.j1939)
+
+/* conversion function between struct sock::sk_priority from linux and
+ * j1939 priority field
+ */
+static inline priority_t j1939_prio(u32 sk_priority)
+{
+	sk_priority = min(sk_priority, 7U);
+
+	return 7 - sk_priority;
+}
+
+static inline u32 j1939_to_sk_priority(priority_t prio)
+{
+	return 7 - prio;
+}
+
+/* function to see if pgn is to be evaluated */
+static inline bool j1939_pgn_is_valid(pgn_t pgn)
+{
+	return pgn <= J1939_PGN_MAX;
+}
+
+/* test function to avoid non-zero DA placeholder for pdu1 pgn's */
+static inline bool j1939_pgn_is_clean_pdu(pgn_t pgn)
+{
+	if (j1939_pgn_is_pdu1(pgn))
+		return !(pgn & 0xff);
+	else
+		return true;
+}
+
+static inline void j1939_sock_pending_add(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	atomic_inc(&jsk->skb_pending);
+}
+
+static int j1939_sock_pending_get(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	return atomic_read(&jsk->skb_pending);
+}
+
+void j1939_sock_pending_del(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	/* atomic_dec_return returns the new value */
+	if (!atomic_dec_return(&jsk->skb_pending))
+		wake_up(&jsk->waitq);	/* no pending SKB's */
+}
+
+static void j1939_jsk_add(struct j1939_priv *priv, struct j1939_sock *jsk)
+{
+	jsk->state |= J1939_SOCK_BOUND;
+	j1939_priv_get(priv);
+	jsk->priv = priv;
+
+	spin_lock_bh(&priv->j1939_socks_lock);
+	list_add_tail(&jsk->list, &priv->j1939_socks);
+	spin_unlock_bh(&priv->j1939_socks_lock);
+}
+
+static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
+{
+	spin_lock_bh(&priv->j1939_socks_lock);
+	list_del_init(&jsk->list);
+	spin_unlock_bh(&priv->j1939_socks_lock);
+
+	jsk->priv = NULL;
+	j1939_priv_put(priv);
+	jsk->state &= ~J1939_SOCK_BOUND;
+}
+
+static bool j1939_sk_queue_session(struct j1939_session *session)
+{
+	struct j1939_sock *jsk = j1939_sk(session->sk);
+	bool empty;
+
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	empty = list_empty(&jsk->sk_session_queue);
+	j1939_session_get(session);
+	list_add_tail(&session->sk_session_queue_entry, &jsk->sk_session_queue);
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+	j1939_sock_pending_add(&jsk->sk);
+
+	return empty;
+}
+
+static struct
+j1939_session *j1939_sk_get_incomplete_session(struct j1939_sock *jsk)
+{
+	struct j1939_session *session = NULL;
+
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	if (!list_empty(&jsk->sk_session_queue)) {
+		session = list_last_entry(&jsk->sk_session_queue,
+					  struct j1939_session,
+					  sk_session_queue_entry);
+		if (session->total_queued_size == session->total_message_size)
+			session = NULL;
+		else
+			j1939_session_get(session);
+	}
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+
+	return session;
+}
+
+static void j1939_sk_queue_drop_all(struct j1939_priv *priv,
+				    struct j1939_sock *jsk, int err)
+{
+	struct j1939_session *session, *tmp;
+
+	netdev_dbg(priv->ndev, "%s: err: %i\n", __func__, err);
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	list_for_each_entry_safe(session, tmp, &jsk->sk_session_queue,
+				 sk_session_queue_entry) {
+		list_del_init(&session->sk_session_queue_entry);
+		session->err = err;
+		j1939_session_put(session);
+	}
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+}
+
+static void j1939_sk_queue_activate_next_locked(struct j1939_session *session)
+{
+	struct j1939_sock *jsk;
+	struct j1939_session *first;
+	int err;
+
+	/* RX-Session don't have a socket (yet) */
+	if (!session->sk)
+		return;
+
+	jsk = j1939_sk(session->sk);
+	lockdep_assert_held(&jsk->sk_session_queue_lock);
+
+	err = session->err;
+
+	first = list_first_entry_or_null(&jsk->sk_session_queue,
+					 struct j1939_session,
+					 sk_session_queue_entry);
+
+	/* Some else has already activated the next session */
+	if (first != session)
+		return;
+
+activate_next:
+	list_del_init(&first->sk_session_queue_entry);
+	j1939_session_put(first);
+	first = list_first_entry_or_null(&jsk->sk_session_queue,
+					 struct j1939_session,
+					 sk_session_queue_entry);
+	if (!first)
+		return;
+
+	if (WARN_ON_ONCE(j1939_session_activate(first))) {
+		first->err = -EBUSY;
+		goto activate_next;
+	} else {
+		/* Give receiver some time (arbitrary chosen) to recover */
+		int time_ms = 0;
+
+		if (err)
+			time_ms = 10 + prandom_u32_max(16);
+
+		j1939_tp_schedule_txtimer(first, time_ms);
+	}
+}
+
+void j1939_sk_queue_activate_next(struct j1939_session *session)
+{
+	struct j1939_sock *jsk;
+
+	if (!session->sk)
+		return;
+
+	jsk = j1939_sk(session->sk);
+
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	j1939_sk_queue_activate_next_locked(session);
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+}
+
+static bool j1939_sk_match_dst(struct j1939_sock *jsk,
+			       const struct j1939_sk_buff_cb *skcb)
+{
+	if ((jsk->state & J1939_SOCK_PROMISC))
+		return true;
+
+	/* Destination address filter */
+	if (jsk->addr.src_name && skcb->addr.dst_name) {
+		if (jsk->addr.src_name != skcb->addr.dst_name)
+			return false;
+	} else {
+		/* receive (all sockets) if
+		 * - all packages that match our bind() address
+		 * - all broadcast on a socket if SO_BROADCAST
+		 *   is set
+		 */
+		if (j1939_address_is_unicast(skcb->addr.da)) {
+			if (jsk->addr.sa != skcb->addr.da)
+				return false;
+		} else if (!sock_flag(&jsk->sk, SOCK_BROADCAST)) {
+			/* receiving broadcast without SO_BROADCAST
+			 * flag is not allowed
+			 */
+			return false;
+		}
+	}
+
+	/* Source address filter */
+	if (jsk->state & J1939_SOCK_CONNECTED) {
+		/* receive (all sockets) if
+		 * - all packages that match our connect() name or address
+		 */
+		if (jsk->addr.dst_name && skcb->addr.src_name) {
+			if (jsk->addr.dst_name != skcb->addr.src_name)
+				return false;
+		} else {
+			if (jsk->addr.da != skcb->addr.sa)
+				return false;
+		}
+	}
+
+	/* PGN filter */
+	if (j1939_pgn_is_valid(jsk->pgn_rx_filter) &&
+	    jsk->pgn_rx_filter != skcb->addr.pgn)
+		return false;
+
+	return true;
+}
+
+/* matches skb control buffer (addr) with a j1939 filter */
+static bool j1939_sk_match_filter(struct j1939_sock *jsk,
+				  const struct j1939_sk_buff_cb *skcb)
+{
+	const struct j1939_filter *f = jsk->filters;
+	int nfilter = jsk->nfilters;
+
+	if (!nfilter)
+		/* receive all when no filters are assigned */
+		return true;
+
+	for (; nfilter; ++f, --nfilter) {
+		if ((skcb->addr.pgn & f->pgn_mask) != f->pgn)
+			continue;
+		if ((skcb->addr.sa & f->addr_mask) != f->addr)
+			continue;
+		if ((skcb->addr.src_name & f->name_mask) != f->name)
+			continue;
+		return true;
+	}
+	return false;
+}
+
+static bool j1939_sk_recv_match_one(struct j1939_sock *jsk,
+				    const struct j1939_sk_buff_cb *skcb)
+{
+	if (!(jsk->state & J1939_SOCK_BOUND))
+		return false;
+
+	if (!j1939_sk_match_dst(jsk, skcb))
+		return false;
+
+	if (!j1939_sk_match_filter(jsk, skcb))
+		return false;
+
+	return true;
+}
+
+static void j1939_sk_recv_one(struct j1939_sock *jsk, struct sk_buff *oskb)
+{
+	const struct j1939_sk_buff_cb *oskcb = j1939_skb_to_cb(oskb);
+	struct j1939_sk_buff_cb *skcb;
+	struct sk_buff *skb;
+
+	if (oskb->sk == &jsk->sk)
+		return;
+
+	if (!j1939_sk_recv_match_one(jsk, oskcb))
+		return;
+
+	skb = skb_clone(oskb, GFP_ATOMIC);
+	if (!skb) {
+		pr_warn("skb clone failed\n");
+		return;
+	}
+	can_skb_set_owner(skb, oskb->sk);
+
+	skcb = j1939_skb_to_cb(skb);
+	skcb->msg_flags &= ~(MSG_DONTROUTE);
+	if (skb->sk)
+		skcb->msg_flags |= MSG_DONTROUTE;
+
+	if (sock_queue_rcv_skb(&jsk->sk, skb) < 0)
+		kfree_skb(skb);
+}
+
+bool j1939_sk_recv_match(struct j1939_priv *priv, struct j1939_sk_buff_cb *skcb)
+{
+	struct j1939_sock *jsk;
+	bool match = false;
+
+	spin_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		match = j1939_sk_recv_match_one(jsk, skcb);
+		if (match)
+			break;
+	}
+	spin_unlock_bh(&priv->j1939_socks_lock);
+
+	return match;
+}
+
+void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sock *jsk;
+
+	spin_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		j1939_sk_recv_one(jsk, skb);
+	}
+	spin_unlock_bh(&priv->j1939_socks_lock);
+}
+
+static int j1939_sk_init(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	/* Ensure that "sk" is first member in "struct j1939_sock", so that we
+	 * can skip it during memset().
+	 */
+	BUILD_BUG_ON(offsetof(struct j1939_sock, sk) != 0);
+	memset((void *)jsk + sizeof(jsk->sk), 0x0,
+	       sizeof(*jsk) - sizeof(jsk->sk));
+
+	INIT_LIST_HEAD(&jsk->list);
+	init_waitqueue_head(&jsk->waitq);
+	jsk->sk.sk_priority = j1939_to_sk_priority(6);
+	jsk->sk.sk_reuse = 1; /* per default */
+	jsk->addr.sa = J1939_NO_ADDR;
+	jsk->addr.da = J1939_NO_ADDR;
+	jsk->addr.pgn = J1939_NO_PGN;
+	jsk->pgn_rx_filter = J1939_NO_PGN;
+	atomic_set(&jsk->skb_pending, 0);
+	spin_lock_init(&jsk->sk_session_queue_lock);
+	INIT_LIST_HEAD(&jsk->sk_session_queue);
+
+	return 0;
+}
+
+static int j1939_sk_sanity_check(struct sockaddr_can *addr, int len)
+{
+	if (!addr)
+		return -EDESTADDRREQ;
+	if (len < J1939_MIN_NAMELEN)
+		return -EINVAL;
+	if (addr->can_family != AF_CAN)
+		return -EINVAL;
+	if (!addr->can_ifindex)
+		return -ENODEV;
+	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
+	    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct j1939_sock *jsk = j1939_sk(sock->sk);
+	struct j1939_priv *priv = jsk->priv;
+	struct sock *sk = sock->sk;
+	struct net *net = sock_net(sk);
+	int ret = 0;
+
+	ret = j1939_sk_sanity_check(addr, len);
+	if (ret)
+		return ret;
+
+	lock_sock(sock->sk);
+
+	/* Already bound to an interface? */
+	if (jsk->state & J1939_SOCK_BOUND) {
+		/* A re-bind() to a different interface is not
+		 * supported.
+		 */
+		if (jsk->ifindex != addr->can_ifindex) {
+			ret = -EINVAL;
+			goto out_release_sock;
+		}
+
+		/* drop old references */
+		j1939_jsk_del(priv, jsk);
+		j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
+	} else {
+		struct net_device *ndev;
+
+		ndev = dev_get_by_index(net, addr->can_ifindex);
+		if (!ndev) {
+			ret = -ENODEV;
+			goto out_release_sock;
+		}
+
+		if (ndev->type != ARPHRD_CAN) {
+			dev_put(ndev);
+			ret = -ENODEV;
+			goto out_release_sock;
+		}
+
+		priv = j1939_netdev_start(ndev);
+		dev_put(ndev);
+		if (IS_ERR(priv)) {
+			ret = PTR_ERR(priv);
+			goto out_release_sock;
+		}
+
+		jsk->ifindex = addr->can_ifindex;
+	}
+
+	/* set default transmit pgn */
+	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
+		jsk->pgn_rx_filter = addr->can_addr.j1939.pgn;
+	jsk->addr.src_name = addr->can_addr.j1939.name;
+	jsk->addr.sa = addr->can_addr.j1939.addr;
+
+	/* get new references */
+	ret = j1939_local_ecu_get(priv, jsk->addr.src_name, jsk->addr.sa);
+	if (ret) {
+		j1939_netdev_stop(priv);
+		goto out_release_sock;
+	}
+
+	j1939_jsk_add(priv, jsk);
+
+ out_release_sock: /* fall through */
+	release_sock(sock->sk);
+
+	return ret;
+}
+
+static int j1939_sk_connect(struct socket *sock, struct sockaddr *uaddr,
+			    int len, int flags)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct j1939_sock *jsk = j1939_sk(sock->sk);
+	int ret = 0;
+
+	ret = j1939_sk_sanity_check(addr, len);
+	if (ret)
+		return ret;
+
+	lock_sock(sock->sk);
+
+	/* bind() before connect() is mandatory */
+	if (!(jsk->state & J1939_SOCK_BOUND)) {
+		ret = -EINVAL;
+		goto out_release_sock;
+	}
+
+	/* A connect() to a different interface is not supported. */
+	if (jsk->ifindex != addr->can_ifindex) {
+		ret = -EINVAL;
+		goto out_release_sock;
+	}
+
+	if (!addr->can_addr.j1939.name &&
+	    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
+	    !sock_flag(&jsk->sk, SOCK_BROADCAST)) {
+		/* broadcast, but SO_BROADCAST not set */
+		ret = -EACCES;
+		goto out_release_sock;
+	}
+
+	jsk->addr.dst_name = addr->can_addr.j1939.name;
+	jsk->addr.da = addr->can_addr.j1939.addr;
+
+	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
+		jsk->addr.pgn = addr->can_addr.j1939.pgn;
+
+	jsk->state |= J1939_SOCK_CONNECTED;
+
+ out_release_sock: /* fall through */
+	release_sock(sock->sk);
+
+	return ret;
+}
+
+static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr,
+				       const struct j1939_sock *jsk, int peer)
+{
+	addr->can_family = AF_CAN;
+	addr->can_ifindex = jsk->ifindex;
+	addr->can_addr.j1939.pgn = jsk->addr.pgn;
+	if (peer) {
+		addr->can_addr.j1939.name = jsk->addr.dst_name;
+		addr->can_addr.j1939.addr = jsk->addr.da;
+	} else {
+		addr->can_addr.j1939.name = jsk->addr.src_name;
+		addr->can_addr.j1939.addr = jsk->addr.sa;
+	}
+}
+
+static int j1939_sk_getname(struct socket *sock, struct sockaddr *uaddr,
+			    int peer)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	int ret = 0;
+
+	lock_sock(sk);
+
+	if (peer && !(jsk->state & J1939_SOCK_CONNECTED)) {
+		ret = -EADDRNOTAVAIL;
+		goto failure;
+	}
+
+	j1939_sk_sock2sockaddr_can(addr, jsk, peer);
+	ret = J1939_MIN_NAMELEN;
+
+ failure:
+	release_sock(sk);
+
+	return ret;
+}
+
+static int j1939_sk_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk;
+
+	if (!sk)
+		return 0;
+
+	jsk = j1939_sk(sk);
+	lock_sock(sk);
+
+	if (jsk->state & J1939_SOCK_BOUND) {
+		struct j1939_priv *priv = jsk->priv;
+
+		if (wait_event_interruptible(jsk->waitq,
+					     !j1939_sock_pending_get(&jsk->sk))) {
+			j1939_cancel_active_session(priv, sk);
+			j1939_sk_queue_drop_all(priv, jsk, ESHUTDOWN);
+		}
+
+		j1939_jsk_del(priv, jsk);
+
+		j1939_local_ecu_put(priv, jsk->addr.src_name,
+				    jsk->addr.sa);
+
+		j1939_netdev_stop(priv);
+	}
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	release_sock(sk);
+	sock_put(sk);
+
+	return 0;
+}
+
+static int j1939_sk_setsockopt_flag(struct j1939_sock *jsk, char __user *optval,
+				    unsigned int optlen, int flag)
+{
+	int tmp;
+
+	if (optlen != sizeof(tmp))
+		return -EINVAL;
+	if (copy_from_user(&tmp, optval, optlen))
+		return -EFAULT;
+	lock_sock(&jsk->sk);
+	if (tmp)
+		jsk->state |= flag;
+	else
+		jsk->state &= ~flag;
+	release_sock(&jsk->sk);
+	return tmp;
+}
+
+static int j1939_sk_setsockopt(struct socket *sock, int level, int optname,
+			       char __user *optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	int tmp, count = 0, ret = 0;
+	struct j1939_filter *filters = NULL, *ofilters;
+
+	if (level != SOL_CAN_J1939)
+		return -EINVAL;
+
+	switch (optname) {
+	case SO_J1939_FILTER:
+		if (optval) {
+			struct j1939_filter *f;
+			int c;
+
+			if (optlen % sizeof(*filters) != 0)
+				return -EINVAL;
+
+			if (optlen > J1939_FILTER_MAX *
+			    sizeof(struct j1939_filter))
+				return -EINVAL;
+
+			count = optlen / sizeof(*filters);
+			filters = memdup_user(optval, optlen);
+			if (IS_ERR(filters))
+				return PTR_ERR(filters);
+
+			for (f = filters, c = count; c; f++, c--) {
+				f->name &= f->name_mask;
+				f->pgn &= f->pgn_mask;
+				f->addr &= f->addr_mask;
+			}
+		}
+
+		lock_sock(&jsk->sk);
+		ofilters = jsk->filters;
+		jsk->filters = filters;
+		jsk->nfilters = count;
+		release_sock(&jsk->sk);
+		kfree(ofilters);
+		return 0;
+	case SO_J1939_PROMISC:
+		return j1939_sk_setsockopt_flag(jsk, optval, optlen,
+						J1939_SOCK_PROMISC);
+	case SO_J1939_ERRQUEUE:
+		ret = j1939_sk_setsockopt_flag(jsk, optval, optlen,
+					       J1939_SOCK_ERRQUEUE);
+		if (ret < 0)
+			return ret;
+
+		if (!(jsk->state & J1939_SOCK_ERRQUEUE))
+			skb_queue_purge(&sk->sk_error_queue);
+		return ret;
+	case SO_J1939_SEND_PRIO:
+		if (optlen != sizeof(tmp))
+			return -EINVAL;
+		if (copy_from_user(&tmp, optval, optlen))
+			return -EFAULT;
+		if (tmp < 0 || tmp > 7)
+			return -EDOM;
+		if (tmp < 2 && !capable(CAP_NET_ADMIN))
+			return -EPERM;
+		lock_sock(&jsk->sk);
+		jsk->sk.sk_priority = j1939_to_sk_priority(tmp);
+		release_sock(&jsk->sk);
+		return 0;
+	default:
+		return -ENOPROTOOPT;
+	}
+}
+
+static int j1939_sk_getsockopt(struct socket *sock, int level, int optname,
+			       char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	int ret, ulen;
+	/* set defaults for using 'int' properties */
+	int tmp = 0;
+	int len = sizeof(tmp);
+	void *val = &tmp;
+
+	if (level != SOL_CAN_J1939)
+		return -EINVAL;
+	if (get_user(ulen, optlen))
+		return -EFAULT;
+	if (ulen < 0)
+		return -EINVAL;
+
+	lock_sock(&jsk->sk);
+	switch (optname) {
+	case SO_J1939_PROMISC:
+		tmp = (jsk->state & J1939_SOCK_PROMISC) ? 1 : 0;
+		break;
+	case SO_J1939_ERRQUEUE:
+		tmp = (jsk->state & J1939_SOCK_ERRQUEUE) ? 1 : 0;
+		break;
+	case SO_J1939_SEND_PRIO:
+		tmp = j1939_prio(jsk->sk.sk_priority);
+		break;
+	default:
+		ret = -ENOPROTOOPT;
+		goto no_copy;
+	}
+
+	/* copy to user, based on 'len' & 'val'
+	 * but most sockopt's are 'int' properties, and have 'len' & 'val'
+	 * left unchanged, but instead modified 'tmp'
+	 */
+	if (len > ulen)
+		ret = -EFAULT;
+	else if (put_user(len, optlen))
+		ret = -EFAULT;
+	else if (copy_to_user(optval, val, len))
+		ret = -EFAULT;
+	else
+		ret = 0;
+ no_copy:
+	release_sock(&jsk->sk);
+	return ret;
+}
+
+static int j1939_sk_recvmsg(struct socket *sock, struct msghdr *msg,
+			    size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	struct j1939_sk_buff_cb *skcb;
+	int ret = 0;
+
+	if (flags & ~(MSG_DONTWAIT | MSG_ERRQUEUE))
+		return -EINVAL;
+
+	if (flags & MSG_ERRQUEUE)
+		return sock_recv_errqueue(sock->sk, msg, size, SOL_CAN_J1939,
+					  SCM_J1939_ERRQUEUE);
+
+	skb = skb_recv_datagram(sk, flags, 0, &ret);
+	if (!skb)
+		return ret;
+
+	if (size < skb->len)
+		msg->msg_flags |= MSG_TRUNC;
+	else
+		size = skb->len;
+
+	ret = memcpy_to_msg(msg, skb->data, size);
+	if (ret < 0) {
+		skb_free_datagram(sk, skb);
+		return ret;
+	}
+
+	skcb = j1939_skb_to_cb(skb);
+	if (j1939_address_is_valid(skcb->addr.da))
+		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_ADDR,
+			 sizeof(skcb->addr.da), &skcb->addr.da);
+
+	if (skcb->addr.dst_name)
+		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_NAME,
+			 sizeof(skcb->addr.dst_name), &skcb->addr.dst_name);
+
+	put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_PRIO,
+		 sizeof(skcb->priority), &skcb->priority);
+
+	if (msg->msg_name) {
+		struct sockaddr_can *paddr = msg->msg_name;
+
+		msg->msg_namelen = J1939_MIN_NAMELEN;
+		memset(msg->msg_name, 0, msg->msg_namelen);
+		paddr->can_family = AF_CAN;
+		paddr->can_ifindex = skb->skb_iif;
+		paddr->can_addr.j1939.name = skcb->addr.src_name;
+		paddr->can_addr.j1939.addr = skcb->addr.sa;
+		paddr->can_addr.j1939.pgn = skcb->addr.pgn;
+	}
+
+	sock_recv_ts_and_drops(msg, sk, skb);
+	msg->msg_flags |= skcb->msg_flags;
+	skb_free_datagram(sk, skb);
+
+	return size;
+}
+
+static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
+					  struct sock *sk,
+					  struct msghdr *msg, size_t size,
+					  int *errcode)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+	struct j1939_sk_buff_cb *skcb;
+	struct sk_buff *skb;
+	int ret;
+
+	skb = sock_alloc_send_skb(sk,
+				  size +
+				  sizeof(struct can_frame) -
+				  sizeof(((struct can_frame *)NULL)->data) +
+				  sizeof(struct can_skb_priv),
+				  msg->msg_flags & MSG_DONTWAIT, &ret);
+	if (!skb)
+		goto failure;
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = ndev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+	skb_reserve(skb, offsetof(struct can_frame, data));
+
+	ret = memcpy_from_msg(skb_put(skb, size), msg, size);
+	if (ret < 0)
+		goto free_skb;
+
+	skb->dev = ndev;
+
+	skcb = j1939_skb_to_cb(skb);
+	memset(skcb, 0, sizeof(*skcb));
+	skcb->addr = jsk->addr;
+	skcb->priority = j1939_prio(sk->sk_priority);
+
+	if (msg->msg_name) {
+		struct sockaddr_can *addr = msg->msg_name;
+
+		if (addr->can_addr.j1939.name ||
+		    addr->can_addr.j1939.addr != J1939_NO_ADDR) {
+			skcb->addr.dst_name = addr->can_addr.j1939.name;
+			skcb->addr.da = addr->can_addr.j1939.addr;
+		}
+		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
+			skcb->addr.pgn = addr->can_addr.j1939.pgn;
+	}
+
+	*errcode = ret;
+	return skb;
+
+free_skb:
+	kfree_skb(skb);
+failure:
+	*errcode = ret;
+	return NULL;
+}
+
+static size_t j1939_sk_opt_stats_get_size(void)
+{
+	return
+		nla_total_size(sizeof(u32)) + /* J1939_NLA_BYTES_ACKED */
+		0;
+}
+
+static struct sk_buff *
+j1939_sk_get_timestamping_opt_stats(struct j1939_session *session)
+{
+	struct sk_buff *stats;
+	u32 size;
+
+	stats = alloc_skb(j1939_sk_opt_stats_get_size(), GFP_ATOMIC);
+	if (!stats)
+		return NULL;
+
+	if (session->skcb.addr.type == J1939_SIMPLE)
+		size = session->total_message_size;
+	else
+		size = min(session->pkt.tx_acked * 7,
+			   session->total_message_size);
+
+	nla_put_u32(stats, J1939_NLA_BYTES_ACKED, size);
+
+	return stats;
+}
+
+void j1939_sk_errqueue(struct j1939_session *session,
+		       enum j1939_sk_errqueue_type type)
+{
+	struct j1939_priv *priv = session->priv;
+	struct sock *sk = session->sk;
+	struct j1939_sock *jsk;
+	struct sock_exterr_skb *serr;
+	struct sk_buff *skb;
+	char *state = "UNK";
+	int err;
+
+	/* currently we have no sk for the RX session */
+	if (!sk)
+		return;
+
+	jsk = j1939_sk(sk);
+
+	if (!(jsk->state & J1939_SOCK_ERRQUEUE))
+		return;
+
+	skb = j1939_sk_get_timestamping_opt_stats(session);
+	if (!skb)
+		return;
+
+	skb->tstamp = ktime_get_real();
+
+	BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb));
+
+	serr = SKB_EXT_ERR(skb);
+	memset(serr, 0, sizeof(*serr));
+	switch (type) {
+	case J1939_ERRQUEUE_ACK:
+		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_ACK))
+			return;
+
+		serr->ee.ee_errno = ENOMSG;
+		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
+		serr->ee.ee_info = SCM_TSTAMP_ACK;
+		state = "ACK";
+		break;
+	case J1939_ERRQUEUE_SCHED:
+		if (!(sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED))
+			return;
+
+		serr->ee.ee_errno = ENOMSG;
+		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
+		serr->ee.ee_info = SCM_TSTAMP_SCHED;
+		state = "SCH";
+		break;
+	case J1939_ERRQUEUE_ABORT:
+		serr->ee.ee_errno = session->err;
+		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
+		serr->ee.ee_info = J1939_EE_INFO_TX_ABORT;
+		state = "ABT";
+		break;
+	default:
+		netdev_err(priv->ndev, "Unknown errqueue type %i\n", type);
+	}
+
+	serr->opt_stats = true;
+	if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
+		serr->ee.ee_data = session->tskey;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p tskey: %i, state: %s\n",
+		   __func__, session, session->tskey, state);
+	err = sock_queue_err_skb(sk, skb);
+
+	if (err)
+		kfree_skb(skb);
+};
+
+void j1939_sk_send_loop_abort(struct sock *sk, int err)
+{
+	sk->sk_err = err;
+
+	sk->sk_error_report(sk);
+}
+
+static int j1939_sk_send_loop(struct j1939_priv *priv,  struct sock *sk,
+			      struct msghdr *msg, size_t size)
+
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+	struct j1939_session *session = j1939_sk_get_incomplete_session(jsk);
+	struct sk_buff *skb;
+	size_t segment_size, todo_size;
+	int ret = 0;
+
+	if (session &&
+	    session->total_message_size != session->total_queued_size + size) {
+		j1939_session_put(session);
+		return -EIO;
+	}
+
+	todo_size = size;
+
+	while (todo_size) {
+		struct j1939_sk_buff_cb *skcb;
+
+		segment_size = min_t(size_t, J1939_MAX_TP_PACKET_SIZE,
+				     todo_size);
+
+		/* Allocate skb for one segment */
+		skb = j1939_sk_alloc_skb(priv->ndev, sk, msg, segment_size,
+					 &ret);
+		if (ret)
+			break;
+
+		skcb = j1939_skb_to_cb(skb);
+
+		if (!session) {
+			/* at this point the size should be full size
+			 * of the session
+			 */
+			skcb->offset = 0;
+			session = j1939_tp_send(priv, skb, size);
+			if (IS_ERR(session)) {
+				ret = PTR_ERR(session);
+				goto kfree_skb;
+			}
+			if (j1939_sk_queue_session(session)) {
+				/* try to activate session if we a
+				 * fist in the queue
+				 */
+				if (!j1939_session_activate(session)) {
+					j1939_tp_schedule_txtimer(session, 0);
+				} else {
+					ret = -EBUSY;
+					session->err = ret;
+					j1939_sk_queue_drop_all(priv, jsk,
+								EBUSY);
+					break;
+				}
+			}
+		} else {
+			skcb->offset = session->total_queued_size;
+			j1939_session_skb_queue(session, skb);
+		}
+
+		todo_size -= segment_size;
+		session->total_queued_size += segment_size;
+	}
+
+	switch (ret) {
+	case 0: /* OK */
+		if (todo_size)
+			netdev_warn(priv->ndev,
+				    "no error found and not completely queued?! %zu\n",
+				    todo_size);
+		ret = size;
+		break;
+	case -ERESTARTSYS:
+		ret = -EINTR;
+		/* fall through */
+	case -EAGAIN: /* OK */
+		if (todo_size != size)
+			ret = size - todo_size;
+		break;
+	default: /* ERROR */
+		break;
+	}
+
+	if (session)
+		j1939_session_put(session);
+
+	return ret;
+
+ kfree_skb:
+	kfree_skb(skb);
+	return ret;
+}
+
+static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
+			    size_t size)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	struct j1939_priv *priv = jsk->priv;
+	int ifindex;
+	int ret;
+
+	/* various socket state tests */
+	if (!(jsk->state & J1939_SOCK_BOUND))
+		return -EBADFD;
+
+	ifindex = jsk->ifindex;
+
+	if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR)
+		/* no source address assigned yet */
+		return -EBADFD;
+
+	/* deal with provided destination address info */
+	if (msg->msg_name) {
+		struct sockaddr_can *addr = msg->msg_name;
+
+		if (msg->msg_namelen < J1939_MIN_NAMELEN)
+			return -EINVAL;
+
+		if (addr->can_family != AF_CAN)
+			return -EINVAL;
+
+		if (addr->can_ifindex && addr->can_ifindex != ifindex)
+			return -EBADFD;
+
+		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
+		    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
+			return -EINVAL;
+
+		if (!addr->can_addr.j1939.name &&
+		    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
+		    !sock_flag(sk, SOCK_BROADCAST))
+			/* broadcast, but SO_BROADCAST not set */
+			return -EACCES;
+	} else {
+		if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
+		    !sock_flag(sk, SOCK_BROADCAST))
+			/* broadcast, but SO_BROADCAST not set */
+			return -EACCES;
+	}
+
+	ret = j1939_sk_send_loop(priv, sk, msg, size);
+
+	return ret;
+}
+
+void j1939_sk_netdev_event_netdown(struct j1939_priv *priv)
+{
+	struct j1939_sock *jsk;
+	int error_code = ENETDOWN;
+
+	spin_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		jsk->sk.sk_err = error_code;
+		if (!sock_flag(&jsk->sk, SOCK_DEAD))
+			jsk->sk.sk_error_report(&jsk->sk);
+
+		j1939_sk_queue_drop_all(priv, jsk, error_code);
+	}
+	spin_unlock_bh(&priv->j1939_socks_lock);
+}
+
+static int j1939_sk_no_ioctlcmd(struct socket *sock, unsigned int cmd,
+				unsigned long arg)
+{
+	/* no ioctls for socket layer -> hand it down to NIC layer */
+	return -ENOIOCTLCMD;
+}
+
+static const struct proto_ops j1939_ops = {
+	.family = PF_CAN,
+	.release = j1939_sk_release,
+	.bind = j1939_sk_bind,
+	.connect = j1939_sk_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = sock_no_accept,
+	.getname = j1939_sk_getname,
+	.poll = datagram_poll,
+	.ioctl = j1939_sk_no_ioctlcmd,
+	.listen = sock_no_listen,
+	.shutdown = sock_no_shutdown,
+	.setsockopt = j1939_sk_setsockopt,
+	.getsockopt = j1939_sk_getsockopt,
+	.sendmsg = j1939_sk_sendmsg,
+	.recvmsg = j1939_sk_recvmsg,
+	.mmap = sock_no_mmap,
+	.sendpage = sock_no_sendpage,
+};
+
+static struct proto j1939_proto __read_mostly = {
+	.name = "CAN_J1939",
+	.owner = THIS_MODULE,
+	.obj_size = sizeof(struct j1939_sock),
+	.init = j1939_sk_init,
+};
+
+const struct can_proto j1939_can_proto = {
+	.type = SOCK_DGRAM,
+	.protocol = CAN_J1939,
+	.ops = &j1939_ops,
+	.prot = &j1939_proto,
+};

net/can/j1939/transport.c

···
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <[e-mail]>
+// Copyright (c) 2018 Protonic,
+//                         Robin van der Gracht <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <[e-mail]>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <[e-mail]>
+
+#include <linux/can/skb.h>
+
+#include "j1939-priv.h"
+
+#define J1939_XTP_TX_RETRY_LIMIT 100
+
+#define J1939_ETP_PGN_CTL 0xc800
+#define J1939_ETP_PGN_DAT 0xc700
+#define J1939_TP_PGN_CTL 0xec00
+#define J1939_TP_PGN_DAT 0xeb00
+
+#define J1939_TP_CMD_RTS 0x10
+#define J1939_TP_CMD_CTS 0x11
+#define J1939_TP_CMD_EOMA 0x13
+#define J1939_TP_CMD_BAM 0x20
+#define J1939_TP_CMD_ABORT 0xff
+
+#define J1939_ETP_CMD_RTS 0x14
+#define J1939_ETP_CMD_CTS 0x15
+#define J1939_ETP_CMD_DPO 0x16
+#define J1939_ETP_CMD_EOMA 0x17
+#define J1939_ETP_CMD_ABORT 0xff
+
+enum j1939_xtp_abort {
+	J1939_XTP_NO_ABORT = 0,
+	J1939_XTP_ABORT_BUSY = 1,
+	/* Already in one or more connection managed sessions and
+	 * cannot support another.
+	 *
+	 * EALREADY:
+	 * Operation already in progress
+	 */
+
+	J1939_XTP_ABORT_RESOURCE = 2,
+	/* System resources were needed for another task so this
+	 * connection managed session was terminated.
+	 *
+	 * EMSGSIZE:
+	 * The socket type requires that message be sent atomically,
+	 * and the size of the message to be sent made this
+	 * impossible.
+	 */
+
+	J1939_XTP_ABORT_TIMEOUT = 3,
+	/* A timeout occurred and this is the connection abort to
+	 * close the session.
+	 *
+	 * EHOSTUNREACH:
+	 * The destination host cannot be reached (probably because
+	 * the host is down or a remote router cannot reach it).
+	 */
+
+	J1939_XTP_ABORT_GENERIC = 4,
+	/* CTS messages received when data transfer is in progress
+	 *
+	 * EBADMSG:
+	 * Not a data message
+	 */
+
+	J1939_XTP_ABORT_FAULT = 5,
+	/* Maximal retransmit request limit reached
+	 *
+	 * ENOTRECOVERABLE:
+	 * State not recoverable
+	 */
+
+	J1939_XTP_ABORT_UNEXPECTED_DATA = 6,
+	/* Unexpected data transfer packet
+	 *
+	 * ENOTCONN:
+	 * Transport endpoint is not connected
+	 */
+
+	J1939_XTP_ABORT_BAD_SEQ = 7,
+	/* Bad sequence number (and software is not able to recover)
+	 *
+	 * EILSEQ:
+	 * Illegal byte sequence
+	 */
+
+	J1939_XTP_ABORT_DUP_SEQ = 8,
+	/* Duplicate sequence number (and software is not able to
+	 * recover)
+	 */
+
+	J1939_XTP_ABORT_EDPO_UNEXPECTED = 9,
+	/* Unexpected EDPO packet (ETP) or Message size > 1785 bytes
+	 * (TP)
+	 */
+
+	J1939_XTP_ABORT_BAD_EDPO_PGN = 10,
+	/* Unexpected EDPO PGN (PGN in EDPO is bad) */
+
+	J1939_XTP_ABORT_EDPO_OUTOF_CTS = 11,
+	/* EDPO number of packets is greater than CTS */
+
+	J1939_XTP_ABORT_BAD_EDPO_OFFSET = 12,
+	/* Bad EDPO offset */
+
+	J1939_XTP_ABORT_OTHER_DEPRECATED = 13,
+	/* Deprecated. Use 250 instead (Any other reason)  */
+
+	J1939_XTP_ABORT_ECTS_UNXPECTED_PGN = 14,
+	/* Unexpected ECTS PGN (PGN in ECTS is bad) */
+
+	J1939_XTP_ABORT_ECTS_TOO_BIG = 15,
+	/* ECTS requested packets exceeds message size */
+
+	J1939_XTP_ABORT_OTHER = 250,
+	/* Any other reason (if a Connection Abort reason is
+	 * identified that is not listed in the table use code 250)
+	 */
+};
+
+static unsigned int j1939_tp_block = 255;
+static unsigned int j1939_tp_packet_delay;
+static unsigned int j1939_tp_padding = 1;
+
+/* helpers */
+static const char *j1939_xtp_abort_to_str(enum j1939_xtp_abort abort)
+{
+	switch (abort) {
+	case J1939_XTP_ABORT_BUSY:
+		return "Already in one or more connection managed sessions and cannot support another.";
+	case J1939_XTP_ABORT_RESOURCE:
+		return "System resources were needed for another task so this connection managed session was terminated.";
+	case J1939_XTP_ABORT_TIMEOUT:
+		return "A timeout occurred and this is the connection abort to close the session.";
+	case J1939_XTP_ABORT_GENERIC:
+		return "CTS messages received when data transfer is in progress";
+	case J1939_XTP_ABORT_FAULT:
+		return "Maximal retransmit request limit reached";
+	case J1939_XTP_ABORT_UNEXPECTED_DATA:
+		return "Unexpected data transfer packet";
+	case J1939_XTP_ABORT_BAD_SEQ:
+		return "Bad sequence number (and software is not able to recover)";
+	case J1939_XTP_ABORT_DUP_SEQ:
+		return "Duplicate sequence number (and software is not able to recover)";
+	case J1939_XTP_ABORT_EDPO_UNEXPECTED:
+		return "Unexpected EDPO packet (ETP) or Message size > 1785 bytes (TP)";
+	case J1939_XTP_ABORT_BAD_EDPO_PGN:
+		return "Unexpected EDPO PGN (PGN in EDPO is bad)";
+	case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
+		return "EDPO number of packets is greater than CTS";
+	case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
+		return "Bad EDPO offset";
+	case J1939_XTP_ABORT_OTHER_DEPRECATED:
+		return "Deprecated. Use 250 instead (Any other reason)";
+	case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
+		return "Unexpected ECTS PGN (PGN in ECTS is bad)";
+	case J1939_XTP_ABORT_ECTS_TOO_BIG:
+		return "ECTS requested packets exceeds message size";
+	case J1939_XTP_ABORT_OTHER:
+		return "Any other reason (if a Connection Abort reason is identified that is not listed in the table use code 250)";
+	default:
+		return "<unknown>";
+	}
+}
+
+static int j1939_xtp_abort_to_errno(struct j1939_priv *priv,
+				    enum j1939_xtp_abort abort)
+{
+	int err;
+
+	switch (abort) {
+	case J1939_XTP_NO_ABORT:
+		WARN_ON_ONCE(abort == J1939_XTP_NO_ABORT);
+		err = 0;
+		break;
+	case J1939_XTP_ABORT_BUSY:
+		err = EALREADY;
+		break;
+	case J1939_XTP_ABORT_RESOURCE:
+		err = EMSGSIZE;
+		break;
+	case J1939_XTP_ABORT_TIMEOUT:
+		err = EHOSTUNREACH;
+		break;
+	case J1939_XTP_ABORT_GENERIC:
+		err = EBADMSG;
+		break;
+	case J1939_XTP_ABORT_FAULT:
+		err = ENOTRECOVERABLE;
+		break;
+	case J1939_XTP_ABORT_UNEXPECTED_DATA:
+		err = ENOTCONN;
+		break;
+	case J1939_XTP_ABORT_BAD_SEQ:
+		err = EILSEQ;
+		break;
+	case J1939_XTP_ABORT_DUP_SEQ:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_EDPO_UNEXPECTED:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_BAD_EDPO_PGN:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_OTHER_DEPRECATED:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_ECTS_TOO_BIG:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_OTHER:
+		err = EPROTO;
+		break;
+	default:
+		netdev_warn(priv->ndev, "Unknown abort code %i", abort);
+		err = EPROTO;
+	}
+
+	return err;
+}
+
+static inline void j1939_session_list_lock(struct j1939_priv *priv)
+{
+	spin_lock_bh(&priv->active_session_list_lock);
+}
+
+static inline void j1939_session_list_unlock(struct j1939_priv *priv)
+{
+	spin_unlock_bh(&priv->active_session_list_lock);
+}
+
+void j1939_session_get(struct j1939_session *session)
+{
+	kref_get(&session->kref);
+}
+
+/* session completion functions */
+static void __j1939_session_drop(struct j1939_session *session)
+{
+	if (!session->transmission)
+		return;
+
+	j1939_sock_pending_del(session->sk);
+}
+
+static void j1939_session_destroy(struct j1939_session *session)
+{
+	if (session->err)
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_ABORT);
+	else
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_ACK);
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	skb_queue_purge(&session->skb_queue);
+	__j1939_session_drop(session);
+	j1939_priv_put(session->priv);
+	kfree(session);
+}
+
+static void __j1939_session_release(struct kref *kref)
+{
+	struct j1939_session *session = container_of(kref, struct j1939_session,
+						     kref);
+
+	j1939_session_destroy(session);
+}
+
+void j1939_session_put(struct j1939_session *session)
+{
+	kref_put(&session->kref, __j1939_session_release);
+}
+
+static void j1939_session_txtimer_cancel(struct j1939_session *session)
+{
+	if (hrtimer_cancel(&session->txtimer))
+		j1939_session_put(session);
+}
+
+static void j1939_session_rxtimer_cancel(struct j1939_session *session)
+{
+	if (hrtimer_cancel(&session->rxtimer))
+		j1939_session_put(session);
+}
+
+void j1939_session_timers_cancel(struct j1939_session *session)
+{
+	j1939_session_txtimer_cancel(session);
+	j1939_session_rxtimer_cancel(session);
+}
+
+static inline bool j1939_cb_is_broadcast(const struct j1939_sk_buff_cb *skcb)
+{
+	return (!skcb->addr.dst_name && (skcb->addr.da == 0xff));
+}
+
+static void j1939_session_skb_drop_old(struct j1939_session *session)
+{
+	struct sk_buff *do_skb;
+	struct j1939_sk_buff_cb *do_skcb;
+	unsigned int offset_start;
+	unsigned long flags;
+
+	if (skb_queue_len(&session->skb_queue) < 2)
+		return;
+
+	offset_start = session->pkt.tx_acked * 7;
+
+	spin_lock_irqsave(&session->skb_queue.lock, flags);
+	do_skb = skb_peek(&session->skb_queue);
+	do_skcb = j1939_skb_to_cb(do_skb);
+
+	if ((do_skcb->offset + do_skb->len) < offset_start) {
+		__skb_unlink(do_skb, &session->skb_queue);
+		kfree_skb(do_skb);
+	}
+	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
+}
+
+void j1939_session_skb_queue(struct j1939_session *session,
+			     struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_priv *priv = session->priv;
+
+	j1939_ac_fixup(priv, skb);
+
+	if (j1939_address_is_unicast(skcb->addr.da) &&
+	    priv->ents[skcb->addr.da].nusers)
+		skcb->flags |= J1939_ECU_LOCAL_DST;
+
+	skcb->flags |= J1939_ECU_LOCAL_SRC;
+
+	skb_queue_tail(&session->skb_queue, skb);
+}
+
+static struct sk_buff *j1939_session_skb_find(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	struct sk_buff *skb = NULL;
+	struct sk_buff *do_skb;
+	struct j1939_sk_buff_cb *do_skcb;
+	unsigned int offset_start;
+	unsigned long flags;
+
+	offset_start = session->pkt.dpo * 7;
+
+	spin_lock_irqsave(&session->skb_queue.lock, flags);
+	skb_queue_walk(&session->skb_queue, do_skb) {
+		do_skcb = j1939_skb_to_cb(do_skb);
+
+		if (offset_start >= do_skcb->offset &&
+		    offset_start < (do_skcb->offset + do_skb->len)) {
+			skb = do_skb;
+		}
+	}
+	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
+
+	if (!skb)
+		netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
+			   __func__, session, offset_start,
+			   skb_queue_len(&session->skb_queue));
+
+	return skb;
+}
+
+/* see if we are receiver
+ * returns 0 for broadcasts, although we will receive them
+ */
+static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
+{
+	return skcb->flags & J1939_ECU_LOCAL_DST;
+}
+
+/* see if we are sender */
+static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
+{
+	return skcb->flags & J1939_ECU_LOCAL_SRC;
+}
+
+/* see if we are involved as either receiver or transmitter */
+static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
+{
+	if (swap)
+		return j1939_tp_im_receiver(skcb);
+	else
+		return j1939_tp_im_transmitter(skcb);
+}
+
+static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
+{
+	return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
+}
+
+/* extract pgn from flow-ctl message */
+static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
+{
+	pgn_t pgn;
+
+	pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
+	if (j1939_pgn_is_pdu1(pgn))
+		pgn &= 0xffff00;
+	return pgn;
+}
+
+static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
+{
+	return (dat[2] << 8) + (dat[1] << 0);
+}
+
+static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
+{
+	return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
+}
+
+static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
+{
+	return (dat[4] << 24) | (dat[3] << 16) |
+		(dat[2] << 8) | (dat[1] << 0);
+}
+
+/* find existing session:
+ * reverse: swap cb's src & dst
+ * there is no problem with matching broadcasts, since
+ * broadcasts (no dst, no da) would never call this
+ * with reverse == true
+ */
+static bool j1939_session_match(struct j1939_addr *se_addr,
+				struct j1939_addr *sk_addr, bool reverse)
+{
+	if (se_addr->type != sk_addr->type)
+		return false;
+
+	if (reverse) {
+		if (se_addr->src_name) {
+			if (se_addr->src_name != sk_addr->dst_name)
+				return false;
+		} else if (se_addr->sa != sk_addr->da) {
+			return false;
+		}
+
+		if (se_addr->dst_name) {
+			if (se_addr->dst_name != sk_addr->src_name)
+				return false;
+		} else if (se_addr->da != sk_addr->sa) {
+			return false;
+		}
+	} else {
+		if (se_addr->src_name) {
+			if (se_addr->src_name != sk_addr->src_name)
+				return false;
+		} else if (se_addr->sa != sk_addr->sa) {
+			return false;
+		}
+
+		if (se_addr->dst_name) {
+			if (se_addr->dst_name != sk_addr->dst_name)
+				return false;
+		} else if (se_addr->da != sk_addr->da) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static struct
+j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
+						struct list_head *root,
+						struct j1939_addr *addr,
+						bool reverse, bool transmitter)
+{
+	struct j1939_session *session;
+
+	lockdep_assert_held(&priv->active_session_list_lock);
+
+	list_for_each_entry(session, root, active_session_list_entry) {
+		j1939_session_get(session);
+		if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
+		    session->transmission == transmitter)
+			return session;
+		j1939_session_put(session);
+	}
+
+	return NULL;
+}
+
+static struct
+j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
+					struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	lockdep_assert_held(&priv->active_session_list_lock);
+
+	list_for_each_entry(session, &priv->active_session_list,
+			    active_session_list_entry) {
+		j1939_session_get(session);
+		if (session->skcb.addr.type == J1939_SIMPLE &&
+		    session->tskey == skcb->tskey && session->sk == skb->sk)
+			return session;
+		j1939_session_put(session);
+	}
+
+	return NULL;
+}
+
+static struct
+j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
+					 struct j1939_addr *addr,
+					 bool reverse, bool transmitter)
+{
+	struct j1939_session *session;
+
+	j1939_session_list_lock(priv);
+	session = j1939_session_get_by_addr_locked(priv,
+						   &priv->active_session_list,
+						   addr, reverse, transmitter);
+	j1939_session_list_unlock(priv);
+
+	return session;
+}
+
+static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
+{
+	u8 tmp = 0;
+
+	swap(skcb->addr.dst_name, skcb->addr.src_name);
+	swap(skcb->addr.da, skcb->addr.sa);
+
+	/* swap SRC and DST flags, leave other untouched */
+	if (skcb->flags & J1939_ECU_LOCAL_SRC)
+		tmp |= J1939_ECU_LOCAL_DST;
+	if (skcb->flags & J1939_ECU_LOCAL_DST)
+		tmp |= J1939_ECU_LOCAL_SRC;
+	skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
+	skcb->flags |= tmp;
+}
+
+static struct
+sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
+			     const struct j1939_sk_buff_cb *re_skcb,
+			     bool ctl,
+			     bool swap_src_dst)
+{
+	struct sk_buff *skb;
+	struct j1939_sk_buff_cb *skcb;
+
+	skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
+			GFP_ATOMIC);
+	if (unlikely(!skb))
+		return ERR_PTR(-ENOMEM);
+
+	skb->dev = priv->ndev;
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
+	/* reserve CAN header */
+	skb_reserve(skb, offsetof(struct can_frame, data));
+
+	memcpy(skb->cb, re_skcb, sizeof(skb->cb));
+	skcb = j1939_skb_to_cb(skb);
+	if (swap_src_dst)
+		j1939_skbcb_swap(skcb);
+
+	if (ctl) {
+		if (skcb->addr.type == J1939_ETP)
+			skcb->addr.pgn = J1939_ETP_PGN_CTL;
+		else
+			skcb->addr.pgn = J1939_TP_PGN_CTL;
+	} else {
+		if (skcb->addr.type == J1939_ETP)
+			skcb->addr.pgn = J1939_ETP_PGN_DAT;
+		else
+			skcb->addr.pgn = J1939_TP_PGN_DAT;
+	}
+
+	return skb;
+}
+
+/* TP transmit packet functions */
+static int j1939_tp_tx_dat(struct j1939_session *session,
+			   const u8 *dat, int len)
+{
+	struct j1939_priv *priv = session->priv;
+	struct sk_buff *skb;
+
+	skb = j1939_tp_tx_dat_new(priv, &session->skcb,
+				  false, false);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	skb_put_data(skb, dat, len);
+	if (j1939_tp_padding && len < 8)
+		memset(skb_put(skb, 8 - len), 0xff, 8 - len);
+
+	return j1939_send_one(priv, skb);
+}
+
+static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
+			       const struct j1939_sk_buff_cb *re_skcb,
+			       bool swap_src_dst, pgn_t pgn, const u8 *dat)
+{
+	struct sk_buff *skb;
+	u8 *skdat;
+
+	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
+		return 0;
+
+	skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	skdat = skb_put(skb, 8);
+	memcpy(skdat, dat, 5);
+	skdat[5] = (pgn >> 0);
+	skdat[6] = (pgn >> 8);
+	skdat[7] = (pgn >> 16);
+
+	return j1939_send_one(priv, skb);
+}
+
+static inline int j1939_tp_tx_ctl(struct j1939_session *session,
+				  bool swap_src_dst, const u8 *dat)
+{
+	struct j1939_priv *priv = session->priv;
+
+	return j1939_xtp_do_tx_ctl(priv, &session->skcb,
+				   swap_src_dst,
+				   session->skcb.addr.pgn, dat);
+}
+
+static int j1939_xtp_tx_abort(struct j1939_priv *priv,
+			      const struct j1939_sk_buff_cb *re_skcb,
+			      bool swap_src_dst,
+			      enum j1939_xtp_abort err,
+			      pgn_t pgn)
+{
+	u8 dat[5];
+
+	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
+		return 0;
+
+	memset(dat, 0xff, sizeof(dat));
+	dat[0] = J1939_TP_CMD_ABORT;
+	dat[1] = err;
+	return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
+}
+
+void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
+{
+	j1939_session_get(session);
+	hrtimer_start(&session->txtimer, ms_to_ktime(msec),
+		      HRTIMER_MODE_REL_SOFT);
+}
+
+static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
+					  int msec)
+{
+	j1939_session_rxtimer_cancel(session);
+	j1939_session_get(session);
+	hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
+		      HRTIMER_MODE_REL_SOFT);
+}
+
+static int j1939_session_tx_rts(struct j1939_session *session)
+{
+	u8 dat[8];
+	int ret;
+
+	memset(dat, 0xff, sizeof(dat));
+
+	dat[1] = (session->total_message_size >> 0);
+	dat[2] = (session->total_message_size >> 8);
+	dat[3] = session->pkt.total;
+
+	if (session->skcb.addr.type == J1939_ETP) {
+		dat[0] = J1939_ETP_CMD_RTS;
+		dat[1] = (session->total_message_size >> 0);
+		dat[2] = (session->total_message_size >> 8);
+		dat[3] = (session->total_message_size >> 16);
+		dat[4] = (session->total_message_size >> 24);
+	} else if (j1939_cb_is_broadcast(&session->skcb)) {
+		dat[0] = J1939_TP_CMD_BAM;
+		/* fake cts for broadcast */
+		session->pkt.tx = 0;
+	} else {
+		dat[0] = J1939_TP_CMD_RTS;
+		dat[4] = dat[3];
+	}
+
+	if (dat[0] == session->last_txcmd)
+		/* done already */
+		return 0;
+
+	ret = j1939_tp_tx_ctl(session, false, dat);
+	if (ret < 0)
+		return ret;
+
+	session->last_txcmd = dat[0];
+	if (dat[0] == J1939_TP_CMD_BAM)
+		j1939_tp_schedule_txtimer(session, 50);
+
+	j1939_tp_set_rxtimeout(session, 1250);
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_session_tx_dpo(struct j1939_session *session)
+{
+	unsigned int pkt;
+	u8 dat[8];
+	int ret;
+
+	memset(dat, 0xff, sizeof(dat));
+
+	dat[0] = J1939_ETP_CMD_DPO;
+	session->pkt.dpo = session->pkt.tx_acked;
+	pkt = session->pkt.dpo;
+	dat[1] = session->pkt.last - session->pkt.tx_acked;
+	dat[2] = (pkt >> 0);
+	dat[3] = (pkt >> 8);
+	dat[4] = (pkt >> 16);
+
+	ret = j1939_tp_tx_ctl(session, false, dat);
+	if (ret < 0)
+		return ret;
+
+	session->last_txcmd = dat[0];
+	j1939_tp_set_rxtimeout(session, 1250);
+	session->pkt.tx = session->pkt.tx_acked;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_session_tx_dat(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_sk_buff_cb *skcb;
+	int offset, pkt_done, pkt_end;
+	unsigned int len, pdelay;
+	struct sk_buff *se_skb;
+	const u8 *tpdat;
+	int ret = 0;
+	u8 dat[8];
+
+	se_skb = j1939_session_skb_find(session);
+	if (!se_skb)
+		return -ENOBUFS;
+
+	skcb = j1939_skb_to_cb(se_skb);
+	tpdat = se_skb->data;
+	ret = 0;
+	pkt_done = 0;
+	if (session->skcb.addr.type != J1939_ETP &&
+	    j1939_cb_is_broadcast(&session->skcb))
+		pkt_end = session->pkt.total;
+	else
+		pkt_end = session->pkt.last;
+
+	while (session->pkt.tx < pkt_end) {
+		dat[0] = session->pkt.tx - session->pkt.dpo + 1;
+		offset = (session->pkt.tx * 7) - skcb->offset;
+		len =  se_skb->len - offset;
+		if (len > 7)
+			len = 7;
+
+		memcpy(&dat[1], &tpdat[offset], len);
+		ret = j1939_tp_tx_dat(session, dat, len + 1);
+		if (ret < 0) {
+			/* ENOBUS == CAN interface TX queue is full */
+			if (ret != -ENOBUFS)
+				netdev_alert(priv->ndev,
+					     "%s: 0x%p: queue data error: %i\n",
+					     __func__, session, ret);
+			break;
+		}
+
+		session->last_txcmd = 0xff;
+		pkt_done++;
+		session->pkt.tx++;
+		pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
+			j1939_tp_packet_delay;
+
+		if (session->pkt.tx < session->pkt.total && pdelay) {
+			j1939_tp_schedule_txtimer(session, pdelay);
+			break;
+		}
+	}
+
+	if (pkt_done)
+		j1939_tp_set_rxtimeout(session, 250);
+
+	return ret;
+}
+
+static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	int ret = 0;
+
+	if (!j1939_tp_im_transmitter(&session->skcb)) {
+		netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
+			     __func__, session);
+		return -EINVAL;
+	}
+
+	switch (session->last_cmd) {
+	case 0:
+		ret = j1939_session_tx_rts(session);
+		break;
+
+	case J1939_ETP_CMD_CTS:
+		if (session->last_txcmd != J1939_ETP_CMD_DPO) {
+			ret = j1939_session_tx_dpo(session);
+			if (ret)
+				return ret;
+		}
+
+		/* fall through */
+	case J1939_TP_CMD_CTS:
+	case 0xff: /* did some data */
+	case J1939_ETP_CMD_DPO:
+	case J1939_TP_CMD_BAM:
+		ret = j1939_session_tx_dat(session);
+
+		break;
+	default:
+		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
+			     __func__, session, session->last_cmd);
+	}
+
+	return ret;
+}
+
+static int j1939_session_tx_cts(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	unsigned int pkt, len;
+	int ret;
+	u8 dat[8];
+
+	if (!j1939_sk_recv_match(priv, &session->skcb))
+		return -ENOENT;
+
+	len = session->pkt.total - session->pkt.rx;
+	len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
+	memset(dat, 0xff, sizeof(dat));
+
+	if (session->skcb.addr.type == J1939_ETP) {
+		pkt = session->pkt.rx + 1;
+		dat[0] = J1939_ETP_CMD_CTS;
+		dat[1] = len;
+		dat[2] = (pkt >> 0);
+		dat[3] = (pkt >> 8);
+		dat[4] = (pkt >> 16);
+	} else {
+		dat[0] = J1939_TP_CMD_CTS;
+		dat[1] = len;
+		dat[2] = session->pkt.rx + 1;
+	}
+
+	if (dat[0] == session->last_txcmd)
+		/* done already */
+		return 0;
+
+	ret = j1939_tp_tx_ctl(session, true, dat);
+	if (ret < 0)
+		return ret;
+
+	if (len)
+		/* only mark cts done when len is set */
+		session->last_txcmd = dat[0];
+	j1939_tp_set_rxtimeout(session, 1250);
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_session_tx_eoma(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	u8 dat[8];
+	int ret;
+
+	if (!j1939_sk_recv_match(priv, &session->skcb))
+		return -ENOENT;
+
+	memset(dat, 0xff, sizeof(dat));
+
+	if (session->skcb.addr.type == J1939_ETP) {
+		dat[0] = J1939_ETP_CMD_EOMA;
+		dat[1] = session->total_message_size >> 0;
+		dat[2] = session->total_message_size >> 8;
+		dat[3] = session->total_message_size >> 16;
+		dat[4] = session->total_message_size >> 24;
+	} else {
+		dat[0] = J1939_TP_CMD_EOMA;
+		dat[1] = session->total_message_size;
+		dat[2] = session->total_message_size >> 8;
+		dat[3] = session->pkt.total;
+	}
+
+	if (dat[0] == session->last_txcmd)
+		/* done already */
+		return 0;
+
+	ret = j1939_tp_tx_ctl(session, true, dat);
+	if (ret < 0)
+		return ret;
+
+	session->last_txcmd = dat[0];
+
+	/* wait for the EOMA packet to come in */
+	j1939_tp_set_rxtimeout(session, 1250);
+
+	netdev_dbg(session->priv->ndev, "%p: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_xtp_txnext_receiver(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	int ret = 0;
+
+	if (!j1939_tp_im_receiver(&session->skcb)) {
+		netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
+			     __func__, session);
+		return -EINVAL;
+	}
+
+	switch (session->last_cmd) {
+	case J1939_TP_CMD_RTS:
+	case J1939_ETP_CMD_RTS:
+		ret = j1939_session_tx_cts(session);
+		break;
+
+	case J1939_ETP_CMD_CTS:
+	case J1939_TP_CMD_CTS:
+	case 0xff: /* did some data */
+	case J1939_ETP_CMD_DPO:
+		if ((session->skcb.addr.type == J1939_TP &&
+		     j1939_cb_is_broadcast(&session->skcb)))
+			break;
+
+		if (session->pkt.rx >= session->pkt.total) {
+			ret = j1939_session_tx_eoma(session);
+		} else if (session->pkt.rx >= session->pkt.last) {
+			session->last_txcmd = 0;
+			ret = j1939_session_tx_cts(session);
+		}
+		break;
+	default:
+		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
+			     __func__, session, session->last_cmd);
+	}
+
+	return ret;
+}
+
+static int j1939_simple_txnext(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	struct sk_buff *se_skb = j1939_session_skb_find(session);
+	struct sk_buff *skb;
+	int ret;
+
+	if (!se_skb)
+		return 0;
+
+	skb = skb_clone(se_skb, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	can_skb_set_owner(skb, se_skb->sk);
+
+	j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
+
+	ret = j1939_send_one(priv, skb);
+	if (ret)
+		return ret;
+
+	j1939_sk_errqueue(session, J1939_ERRQUEUE_SCHED);
+	j1939_sk_queue_activate_next(session);
+
+	return 0;
+}
+
+static bool j1939_session_deactivate_locked(struct j1939_session *session)
+{
+	bool active = false;
+
+	lockdep_assert_held(&session->priv->active_session_list_lock);
+
+	if (session->state >= J1939_SESSION_ACTIVE &&
+	    session->state < J1939_SESSION_ACTIVE_MAX) {
+		active = true;
+
+		list_del_init(&session->active_session_list_entry);
+		session->state = J1939_SESSION_DONE;
+		j1939_session_put(session);
+	}
+
+	return active;
+}
+
+static bool j1939_session_deactivate(struct j1939_session *session)
+{
+	bool active;
+
+	j1939_session_list_lock(session->priv);
+	active = j1939_session_deactivate_locked(session);
+	j1939_session_list_unlock(session->priv);
+
+	return active;
+}
+
+static void
+j1939_session_deactivate_activate_next(struct j1939_session *session)
+{
+	if (j1939_session_deactivate(session))
+		j1939_sk_queue_activate_next(session);
+}
+
+static void j1939_session_cancel(struct j1939_session *session,
+				 enum j1939_xtp_abort err)
+{
+	struct j1939_priv *priv = session->priv;
+
+	WARN_ON_ONCE(!err);
+
+	session->err = j1939_xtp_abort_to_errno(priv, err);
+	/* do not send aborts on incoming broadcasts */
+	if (!j1939_cb_is_broadcast(&session->skcb)) {
+		session->state = J1939_SESSION_WAITING_ABORT;
+		j1939_xtp_tx_abort(priv, &session->skcb,
+				   !session->transmission,
+				   err, session->skcb.addr.pgn);
+	}
+
+	if (session->sk)
+		j1939_sk_send_loop_abort(session->sk, session->err);
+}
+
+static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
+{
+	struct j1939_session *session =
+		container_of(hrtimer, struct j1939_session, txtimer);
+	struct j1939_priv *priv = session->priv;
+	int ret = 0;
+
+	if (session->skcb.addr.type == J1939_SIMPLE) {
+		ret = j1939_simple_txnext(session);
+	} else {
+		if (session->transmission)
+			ret = j1939_xtp_txnext_transmiter(session);
+		else
+			ret = j1939_xtp_txnext_receiver(session);
+	}
+
+	switch (ret) {
+	case -ENOBUFS:
+		/* Retry limit is currently arbitrary chosen */
+		if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
+			session->tx_retry++;
+			j1939_tp_schedule_txtimer(session,
+						  10 + prandom_u32_max(16));
+		} else {
+			netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
+				     __func__, session);
+			session->err = -ENETUNREACH;
+			j1939_session_rxtimer_cancel(session);
+			j1939_session_deactivate_activate_next(session);
+		}
+		break;
+	case -ENETDOWN:
+		/* In this case we should get a netdev_event(), all active
+		 * sessions will be cleared by
+		 * j1939_cancel_all_active_sessions(). So handle this as an
+		 * error, but let j1939_cancel_all_active_sessions() do the
+		 * cleanup including propagation of the error to user space.
+		 */
+		break;
+	case 0:
+		session->tx_retry = 0;
+		break;
+	default:
+		netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
+			     __func__, session, ret);
+		if (session->skcb.addr.type != J1939_SIMPLE) {
+			j1939_tp_set_rxtimeout(session,
+					       J1939_XTP_ABORT_TIMEOUT_MS);
+			j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
+		} else {
+			session->err = ret;
+			j1939_session_rxtimer_cancel(session);
+			j1939_session_deactivate_activate_next(session);
+		}
+	}
+
+	j1939_session_put(session);
+
+	return HRTIMER_NORESTART;
+}
+
+static void j1939_session_completed(struct j1939_session *session)
+{
+	struct sk_buff *skb;
+
+	if (!session->transmission) {
+		skb = j1939_session_skb_find(session);
+		/* distribute among j1939 receivers */
+		j1939_sk_recv(session->priv, skb);
+	}
+
+	j1939_session_deactivate_activate_next(session);
+}
+
+static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
+{
+	struct j1939_session *session = container_of(hrtimer,
+						     struct j1939_session,
+						     rxtimer);
+	struct j1939_priv *priv = session->priv;
+
+	if (session->state == J1939_SESSION_WAITING_ABORT) {
+		netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
+			     __func__, session);
+
+		j1939_session_deactivate_activate_next(session);
+
+	} else if (session->skcb.addr.type == J1939_SIMPLE) {
+		netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
+			     __func__, session);
+
+		/* The message is probably stuck in the CAN controller and can
+		 * be send as soon as CAN bus is in working state again.
+		 */
+		session->err = -ETIME;
+		j1939_session_deactivate(session);
+	} else {
+		netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
+			     __func__, session);
+
+		j1939_session_list_lock(session->priv);
+		if (session->state >= J1939_SESSION_ACTIVE &&
+		    session->state < J1939_SESSION_ACTIVE_MAX) {
+			j1939_session_get(session);
+			hrtimer_start(&session->rxtimer,
+				      ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
+				      HRTIMER_MODE_REL_SOFT);
+			j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
+		}
+		j1939_session_list_unlock(session->priv);
+	}
+
+	j1939_session_put(session);
+
+	return HRTIMER_NORESTART;
+}
+
+static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
+				     const struct sk_buff *skb)
+{
+	const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
+	struct j1939_priv *priv = session->priv;
+	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
+	u8 cmd = skb->data[0];
+
+	if (session->skcb.addr.pgn == pgn)
+		return false;
+
+	switch (cmd) {
+	case J1939_TP_CMD_BAM:
+		abort = J1939_XTP_NO_ABORT;
+		break;
+
+	case J1939_ETP_CMD_RTS:
+	case J1939_TP_CMD_RTS: /* fall through */
+		abort = J1939_XTP_ABORT_BUSY;
+		break;
+
+	case J1939_ETP_CMD_CTS:
+	case J1939_TP_CMD_CTS: /* fall through */
+		abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
+		break;
+
+	case J1939_ETP_CMD_DPO:
+		abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
+		break;
+
+	case J1939_ETP_CMD_EOMA:
+	case J1939_TP_CMD_EOMA: /* fall through */
+		abort = J1939_XTP_ABORT_OTHER;
+		break;
+
+	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
+		abort = J1939_XTP_NO_ABORT;
+		break;
+
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+
+	netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
+		    __func__, session, cmd, pgn, session->skcb.addr.pgn);
+	if (abort != J1939_XTP_NO_ABORT)
+		j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
+
+	return true;
+}
+
+static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
+				   bool reverse, bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	u8 abort = skb->data[1];
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
+					    transmitter);
+	if (!session)
+		return;
+
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		goto abort_put;
+
+	netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
+		    session, j1939_xtp_ctl_to_pgn(skb->data), abort,
+		    j1939_xtp_abort_to_str(abort));
+
+	j1939_session_timers_cancel(session);
+	session->err = j1939_xtp_abort_to_errno(priv, abort);
+	if (session->sk)
+		j1939_sk_send_loop_abort(session->sk, session->err);
+	j1939_session_deactivate_activate_next(session);
+
+abort_put:
+	j1939_session_put(session);
+}
+
+/* abort packets may come in 2 directions */
+static void
+j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
+		   bool transmitter)
+{
+	j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
+	j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
+}
+
+static void
+j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
+{
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		return;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	session->pkt.tx_acked = session->pkt.total;
+	j1939_session_timers_cancel(session);
+	/* transmitted without problems */
+	j1939_session_completed(session);
+}
+
+static void
+j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
+		  bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
+					    transmitter);
+	if (!session)
+		return;
+
+	j1939_xtp_rx_eoma_one(session, skb);
+	j1939_session_put(session);
+}
+
+static void
+j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
+{
+	enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
+	unsigned int pkt;
+	const u8 *dat;
+
+	dat = skb->data;
+
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		return;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	if (session->last_cmd == dat[0]) {
+		err = J1939_XTP_ABORT_DUP_SEQ;
+		goto out_session_cancel;
+	}
+
+	if (session->skcb.addr.type == J1939_ETP)
+		pkt = j1939_etp_ctl_to_packet(dat);
+	else
+		pkt = dat[2];
+
+	if (!pkt)
+		goto out_session_cancel;
+	else if (dat[1] > session->pkt.block /* 0xff for etp */)
+		goto out_session_cancel;
+
+	/* set packet counters only when not CTS(0) */
+	session->pkt.tx_acked = pkt - 1;
+	j1939_session_skb_drop_old(session);
+	session->pkt.last = session->pkt.tx_acked + dat[1];
+	if (session->pkt.last > session->pkt.total)
+		/* safety measure */
+		session->pkt.last = session->pkt.total;
+	/* TODO: do not set tx here, do it in txtimer */
+	session->pkt.tx = session->pkt.tx_acked;
+
+	session->last_cmd = dat[0];
+	if (dat[1]) {
+		j1939_tp_set_rxtimeout(session, 1250);
+		if (session->transmission) {
+			if (session->pkt.tx_acked)
+				j1939_sk_errqueue(session,
+						  J1939_ERRQUEUE_SCHED);
+			j1939_session_txtimer_cancel(session);
+			j1939_tp_schedule_txtimer(session, 0);
+		}
+	} else {
+		/* CTS(0) */
+		j1939_tp_set_rxtimeout(session, 550);
+	}
+	return;
+
+ out_session_cancel:
+	j1939_session_timers_cancel(session);
+	j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
+	j1939_session_cancel(session, err);
+}
+
+static void
+j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
+					    transmitter);
+	if (!session)
+		return;
+	j1939_xtp_rx_cts_one(session, skb);
+	j1939_session_put(session);
+}
+
+static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
+					       struct sk_buff *skb, size_t size)
+{
+	struct j1939_session *session;
+	struct j1939_sk_buff_cb *skcb;
+
+	session = kzalloc(sizeof(*session), gfp_any());
+	if (!session)
+		return NULL;
+
+	INIT_LIST_HEAD(&session->active_session_list_entry);
+	INIT_LIST_HEAD(&session->sk_session_queue_entry);
+	kref_init(&session->kref);
+
+	j1939_priv_get(priv);
+	session->priv = priv;
+	session->total_message_size = size;
+	session->state = J1939_SESSION_NEW;
+
+	skb_queue_head_init(&session->skb_queue);
+	skb_queue_tail(&session->skb_queue, skb);
+
+	skcb = j1939_skb_to_cb(skb);
+	memcpy(&session->skcb, skcb, sizeof(session->skcb));
+
+	hrtimer_init(&session->txtimer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL_SOFT);
+	session->txtimer.function = j1939_tp_txtimer;
+	hrtimer_init(&session->rxtimer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL_SOFT);
+	session->rxtimer.function = j1939_tp_rxtimer;
+
+	netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
+		   __func__, session, skcb->addr.sa, skcb->addr.da);
+
+	return session;
+}
+
+static struct
+j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
+				       int size,
+				       const struct j1939_sk_buff_cb *rel_skcb)
+{
+	struct sk_buff *skb;
+	struct j1939_sk_buff_cb *skcb;
+	struct j1939_session *session;
+
+	skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
+	if (unlikely(!skb))
+		return NULL;
+
+	skb->dev = priv->ndev;
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
+	skcb = j1939_skb_to_cb(skb);
+	memcpy(skcb, rel_skcb, sizeof(*skcb));
+
+	session = j1939_session_new(priv, skb, skb->len);
+	if (!session) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* alloc data area */
+	skb_put(skb, size);
+	/* skb is recounted in j1939_session_new() */
+	return session;
+}
+
+int j1939_session_activate(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_session *active = NULL;
+	int ret = 0;
+
+	j1939_session_list_lock(priv);
+	if (session->skcb.addr.type != J1939_SIMPLE)
+		active = j1939_session_get_by_addr_locked(priv,
+							  &priv->active_session_list,
+							  &session->skcb.addr, false,
+							  session->transmission);
+	if (active) {
+		j1939_session_put(active);
+		ret = -EAGAIN;
+	} else {
+		WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
+		list_add_tail(&session->active_session_list_entry,
+			      &priv->active_session_list);
+		j1939_session_get(session);
+		session->state = J1939_SESSION_ACTIVE;
+
+		netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
+			   __func__, session);
+	}
+	j1939_session_list_unlock(priv);
+
+	return ret;
+}
+
+static struct
+j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
+					    struct sk_buff *skb)
+{
+	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
+	struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	const u8 *dat;
+	pgn_t pgn;
+	int len;
+
+	netdev_dbg(priv->ndev, "%s\n", __func__);
+
+	dat = skb->data;
+	pgn = j1939_xtp_ctl_to_pgn(dat);
+	skcb.addr.pgn = pgn;
+
+	if (!j1939_sk_recv_match(priv, &skcb))
+		return NULL;
+
+	if (skcb.addr.type == J1939_ETP) {
+		len = j1939_etp_ctl_to_size(dat);
+		if (len > J1939_MAX_ETP_PACKET_SIZE)
+			abort = J1939_XTP_ABORT_FAULT;
+		else if (len > priv->tp_max_packet_size)
+			abort = J1939_XTP_ABORT_RESOURCE;
+		else if (len <= J1939_MAX_TP_PACKET_SIZE)
+			abort = J1939_XTP_ABORT_FAULT;
+	} else {
+		len = j1939_tp_ctl_to_size(dat);
+		if (len > J1939_MAX_TP_PACKET_SIZE)
+			abort = J1939_XTP_ABORT_FAULT;
+		else if (len > priv->tp_max_packet_size)
+			abort = J1939_XTP_ABORT_RESOURCE;
+	}
+
+	if (abort != J1939_XTP_NO_ABORT) {
+		j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
+		return NULL;
+	}
+
+	session = j1939_session_fresh_new(priv, len, &skcb);
+	if (!session) {
+		j1939_xtp_tx_abort(priv, &skcb, true,
+				   J1939_XTP_ABORT_RESOURCE, pgn);
+		return NULL;
+	}
+
+	/* initialize the control buffer: plain copy */
+	session->pkt.total = (len + 6) / 7;
+	session->pkt.block = 0xff;
+	if (skcb.addr.type != J1939_ETP) {
+		if (dat[3] != session->pkt.total)
+			netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
+				     __func__, session, session->pkt.total,
+				     dat[3]);
+		session->pkt.total = dat[3];
+		session->pkt.block = min(dat[3], dat[4]);
+	}
+
+	session->pkt.rx = 0;
+	session->pkt.tx = 0;
+
+	WARN_ON_ONCE(j1939_session_activate(session));
+
+	return session;
+}
+
+static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
+					   struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_priv *priv = session->priv;
+
+	if (!session->transmission) {
+		if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+			return -EBUSY;
+
+		/* RTS on active session */
+		j1939_session_timers_cancel(session);
+		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
+		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
+	}
+
+	if (session->last_cmd != 0) {
+		/* we received a second rts on the same connection */
+		netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
+			     __func__, session, skcb->addr.sa, skcb->addr.da,
+			     session->last_cmd);
+
+		j1939_session_timers_cancel(session);
+		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
+		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
+
+		return -EBUSY;
+	}
+
+	if (session->skcb.addr.sa != skcb->addr.sa ||
+	    session->skcb.addr.da != skcb->addr.da)
+		netdev_warn(priv->ndev, "%s: 0x%p: session->skcb.addr.sa=0x%02x skcb->addr.sa=0x%02x session->skcb.addr.da=0x%02x skcb->addr.da=0x%02x\n",
+			    __func__, session,
+			    session->skcb.addr.sa, skcb->addr.sa,
+			    session->skcb.addr.da, skcb->addr.da);
+	/* make sure 'sa' & 'da' are correct !
+	 * They may be 'not filled in yet' for sending
+	 * skb's, since they did not pass the Address Claim ever.
+	 */
+	session->skcb.addr.sa = skcb->addr.sa;
+	session->skcb.addr.da = skcb->addr.da;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
+			     bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	u8 cmd = skb->data[0];
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+					    transmitter);
+
+	if (!session) {
+		if (transmitter) {
+			/* If we're the transmitter and this function is called,
+			 * we received our own RTS. A session has already been
+			 * created.
+			 *
+			 * For some reasons however it might have been destroyed
+			 * already. So don't create a new one here (using
+			 * "j1939_xtp_rx_rts_session_new()") as this will be a
+			 * receiver session.
+			 *
+			 * The reasons the session is already destroyed might
+			 * be:
+			 * - user space closed socket was and the session was
+			 *   aborted
+			 * - session was aborted due to external abort message
+			 */
+			return;
+		}
+		session = j1939_xtp_rx_rts_session_new(priv, skb);
+		if (!session)
+			return;
+	} else {
+		if (j1939_xtp_rx_rts_session_active(session, skb)) {
+			j1939_session_put(session);
+			return;
+		}
+	}
+	session->last_cmd = cmd;
+
+	j1939_tp_set_rxtimeout(session, 1250);
+
+	if (cmd != J1939_TP_CMD_BAM && !session->transmission) {
+		j1939_session_txtimer_cancel(session);
+		j1939_tp_schedule_txtimer(session, 0);
+	}
+
+	j1939_session_put(session);
+}
+
+static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
+				 struct sk_buff *skb)
+{
+	const u8 *dat = skb->data;
+
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		return;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	/* transmitted without problems */
+	session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
+	session->last_cmd = dat[0];
+	j1939_tp_set_rxtimeout(session, 750);
+}
+
+static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
+			     bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+					    transmitter);
+	if (!session) {
+		netdev_info(priv->ndev,
+			    "%s: no connection found\n", __func__);
+		return;
+	}
+
+	j1939_xtp_rx_dpo_one(session, skb);
+	j1939_session_put(session);
+}
+
+static void j1939_xtp_rx_dat_one(struct j1939_session *session,
+				 struct sk_buff *skb)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_sk_buff_cb *skcb;
+	struct sk_buff *se_skb;
+	const u8 *dat;
+	u8 *tpdat;
+	int offset;
+	int nbytes;
+	bool final = false;
+	bool do_cts_eoma = false;
+	int packet;
+
+	skcb = j1939_skb_to_cb(skb);
+	dat = skb->data;
+	if (skb->len <= 1)
+		/* makes no sense */
+		goto out_session_cancel;
+
+	switch (session->last_cmd) {
+	case 0xff:
+		break;
+	case J1939_ETP_CMD_DPO:
+		if (skcb->addr.type == J1939_ETP)
+			break;
+		/* fall through */
+	case J1939_TP_CMD_BAM: /* fall through */
+	case J1939_TP_CMD_CTS: /* fall through */
+		if (skcb->addr.type != J1939_ETP)
+			break;
+		/* fall through */
+	default:
+		netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
+			    session, session->last_cmd);
+		goto out_session_cancel;
+	}
+
+	packet = (dat[0] - 1 + session->pkt.dpo);
+	if (packet > session->pkt.total ||
+	    (session->pkt.rx + 1) > session->pkt.total) {
+		netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
+			    __func__, session);
+		goto out_session_cancel;
+	}
+	se_skb = j1939_session_skb_find(session);
+	if (!se_skb) {
+		netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
+			    session);
+		goto out_session_cancel;
+	}
+
+	skcb = j1939_skb_to_cb(se_skb);
+	offset = packet * 7 - skcb->offset;
+	nbytes = se_skb->len - offset;
+	if (nbytes > 7)
+		nbytes = 7;
+	if (nbytes <= 0 || (nbytes + 1) > skb->len) {
+		netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
+			    __func__, session, nbytes, skb->len);
+		goto out_session_cancel;
+	}
+
+	tpdat = se_skb->data;
+	memcpy(&tpdat[offset], &dat[1], nbytes);
+	if (packet == session->pkt.rx)
+		session->pkt.rx++;
+
+	if (skcb->addr.type != J1939_ETP &&
+	    j1939_cb_is_broadcast(&session->skcb)) {
+		if (session->pkt.rx >= session->pkt.total)
+			final = true;
+	} else {
+		/* never final, an EOMA must follow */
+		if (session->pkt.rx >= session->pkt.last)
+			do_cts_eoma = true;
+	}
+
+	if (final) {
+		j1939_session_completed(session);
+	} else if (do_cts_eoma) {
+		j1939_tp_set_rxtimeout(session, 1250);
+		if (!session->transmission)
+			j1939_tp_schedule_txtimer(session, 0);
+	} else {
+		j1939_tp_set_rxtimeout(session, 250);
+	}
+	session->last_cmd = 0xff;
+	j1939_session_put(session);
+
+	return;
+
+ out_session_cancel:
+	j1939_session_timers_cancel(session);
+	j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
+	j1939_session_cancel(session, J1939_XTP_ABORT_FAULT);
+	j1939_session_put(session);
+}
+
+static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb;
+	struct j1939_session *session;
+
+	skcb = j1939_skb_to_cb(skb);
+
+	if (j1939_tp_im_transmitter(skcb)) {
+		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+						    true);
+		if (!session)
+			netdev_info(priv->ndev, "%s: no tx connection found\n",
+				    __func__);
+		else
+			j1939_xtp_rx_dat_one(session, skb);
+	}
+
+	if (j1939_tp_im_receiver(skcb)) {
+		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+						    false);
+		if (!session)
+			netdev_info(priv->ndev, "%s: no rx connection found\n",
+				    __func__);
+		else
+			j1939_xtp_rx_dat_one(session, skb);
+	}
+}
+
+/* j1939 main intf */
+struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
+				    struct sk_buff *skb, size_t size)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	int ret;
+
+	if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
+	    skcb->addr.pgn == J1939_TP_PGN_CTL ||
+	    skcb->addr.pgn == J1939_ETP_PGN_DAT ||
+	    skcb->addr.pgn == J1939_ETP_PGN_CTL)
+		/* avoid conflict */
+		return ERR_PTR(-EDOM);
+
+	if (size > priv->tp_max_packet_size)
+		return ERR_PTR(-EMSGSIZE);
+
+	if (size <= 8)
+		skcb->addr.type = J1939_SIMPLE;
+	else if (size > J1939_MAX_TP_PACKET_SIZE)
+		skcb->addr.type = J1939_ETP;
+	else
+		skcb->addr.type = J1939_TP;
+
+	if (skcb->addr.type == J1939_ETP &&
+	    j1939_cb_is_broadcast(skcb))
+		return ERR_PTR(-EDESTADDRREQ);
+
+	/* fill in addresses from names */
+	ret = j1939_ac_fixup(priv, skb);
+	if (unlikely(ret))
+		return ERR_PTR(ret);
+
+	/* fix DST flags, it may be used there soon */
+	if (j1939_address_is_unicast(skcb->addr.da) &&
+	    priv->ents[skcb->addr.da].nusers)
+		skcb->flags |= J1939_ECU_LOCAL_DST;
+
+	/* src is always local, I'm sending ... */
+	skcb->flags |= J1939_ECU_LOCAL_SRC;
+
+	/* prepare new session */
+	session = j1939_session_new(priv, skb, size);
+	if (!session)
+		return ERR_PTR(-ENOMEM);
+
+	/* skb is recounted in j1939_session_new() */
+	session->sk = skb->sk;
+	session->transmission = true;
+	session->pkt.total = (size + 6) / 7;
+	session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
+		min(j1939_tp_block ?: 255, session->pkt.total);
+
+	if (j1939_cb_is_broadcast(&session->skcb))
+		/* set the end-packet for broadcast */
+		session->pkt.last = session->pkt.total;
+
+	skcb->tskey = session->sk->sk_tskey++;
+	session->tskey = skcb->tskey;
+
+	return session;
+}
+
+static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	int extd = J1939_TP;
+	u8 cmd = skb->data[0];
+
+	switch (cmd) {
+	case J1939_ETP_CMD_RTS:
+		extd = J1939_ETP;
+		/* fall through */
+	case J1939_TP_CMD_BAM: /* fall through */
+	case J1939_TP_CMD_RTS: /* fall through */
+		if (skcb->addr.type != extd)
+			return;
+
+		if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
+			netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
+				     __func__, skcb->addr.sa);
+			return;
+		}
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_rts(priv, skb, true);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_rts(priv, skb, false);
+
+		break;
+
+	case J1939_ETP_CMD_CTS:
+		extd = J1939_ETP;
+		/* fall through */
+	case J1939_TP_CMD_CTS:
+		if (skcb->addr.type != extd)
+			return;
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_cts(priv, skb, false);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_cts(priv, skb, true);
+
+		break;
+
+	case J1939_ETP_CMD_DPO:
+		if (skcb->addr.type != J1939_ETP)
+			return;
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_dpo(priv, skb, true);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_dpo(priv, skb, false);
+
+		break;
+
+	case J1939_ETP_CMD_EOMA:
+		extd = J1939_ETP;
+		/* fall through */
+	case J1939_TP_CMD_EOMA:
+		if (skcb->addr.type != extd)
+			return;
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_eoma(priv, skb, false);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_eoma(priv, skb, true);
+
+		break;
+
+	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_abort(priv, skb, true);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_abort(priv, skb, false);
+
+		break;
+	default:
+		return;
+	}
+}
+
+int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+
+	if (!j1939_tp_im_involved_anydir(skcb))
+		return 0;
+
+	switch (skcb->addr.pgn) {
+	case J1939_ETP_PGN_DAT:
+		skcb->addr.type = J1939_ETP;
+		/* fall through */
+	case J1939_TP_PGN_DAT:
+		j1939_xtp_rx_dat(priv, skb);
+		break;
+
+	case J1939_ETP_PGN_CTL:
+		skcb->addr.type = J1939_ETP;
+		/* fall through */
+	case J1939_TP_PGN_CTL:
+		if (skb->len < 8)
+			return 0; /* Don't care. Nothing to extract here */
+
+		j1939_tp_cmd_recv(priv, skb);
+		break;
+	default:
+		return 0; /* no problem */
+	}
+	return 1; /* "I processed the message" */
+}
+
+void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_session *session;
+
+	if (!skb->sk)
+		return;
+
+	j1939_session_list_lock(priv);
+	session = j1939_session_get_simple(priv, skb);
+	j1939_session_list_unlock(priv);
+	if (!session) {
+		netdev_warn(priv->ndev,
+			    "%s: Received already invalidated message\n",
+			    __func__);
+		return;
+	}
+
+	j1939_session_timers_cancel(session);
+	j1939_session_deactivate(session);
+	j1939_session_put(session);
+}
+
+int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
+{
+	struct j1939_session *session, *saved;
+
+	netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
+	j1939_session_list_lock(priv);
+	list_for_each_entry_safe(session, saved,
+				 &priv->active_session_list,
+				 active_session_list_entry) {
+		if (!sk || sk == session->sk) {
+			j1939_session_timers_cancel(session);
+			session->err = ESHUTDOWN;
+			j1939_session_deactivate_locked(session);
+		}
+	}
+	j1939_session_list_unlock(priv);
+	return NOTIFY_DONE;
+}
+
+void j1939_tp_init(struct j1939_priv *priv)
+{
+	spin_lock_init(&priv->active_session_list_lock);
+	INIT_LIST_HEAD(&priv->active_session_list);
+	priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
+}

net/can/proc.c

···
 #include <linux/list.h>
 #include <linux/rcupdate.h>
 #include <linux/if_arp.h>
+#include <linux/can/can-ml.h>
 #include <linux/can/core.h>
 
 #include "af_can.h"
···
 
 static void can_init_stats(struct net *net)
 {
-	struct s_stats *can_stats = net->can.can_stats;
-	struct s_pstats *can_pstats = net->can.can_pstats;
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
 	/*
 	 * This memset function is called from a timer context (when
 	 * can_stattimer is active which is the default) OR in a process
 	 * context (reading the proc_fs when can_stattimer is disabled).
 	 */
-	memset(can_stats, 0, sizeof(struct s_stats));
-	can_stats->jiffies_init = jiffies;
+	memset(pkg_stats, 0, sizeof(struct can_pkg_stats));
+	pkg_stats->jiffies_init = jiffies;
 
-	can_pstats->stats_reset++;
+	rcv_lists_stats->stats_reset++;
 
 	if (user_reset) {
 		user_reset = 0;
-		can_pstats->user_reset++;
+		rcv_lists_stats->user_reset++;
 	}
 }
 
···
 
 void can_stat_update(struct timer_list *t)
 {
-	struct net *net = from_timer(net, t, can.can_stattimer);
-	struct s_stats *can_stats = net->can.can_stats;
+	struct net *net = from_timer(net, t, can.stattimer);
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
 	unsigned long j = jiffies; /* snapshot */
 
 	/* restart counting in timer context on user request */
···
 		can_init_stats(net);
 
 	/* restart counting on jiffies overflow */
-	if (j < can_stats->jiffies_init)
+	if (j < pkg_stats->jiffies_init)
 		can_init_stats(net);
 
 	/* prevent overflow in calc_rate() */
-	if (can_stats->rx_frames > (ULONG_MAX / HZ))
+	if (pkg_stats->rx_frames > (ULONG_MAX / HZ))
 		can_init_stats(net);
 
 	/* prevent overflow in calc_rate() */
-	if (can_stats->tx_frames > (ULONG_MAX / HZ))
+	if (pkg_stats->tx_frames > (ULONG_MAX / HZ))
 		can_init_stats(net);
 
 	/* matches overflow - very improbable */
-	if (can_stats->matches > (ULONG_MAX / 100))
+	if (pkg_stats->matches > (ULONG_MAX / 100))
 		can_init_stats(net);
 
 	/* calc total values */
-	if (can_stats->rx_frames)
-		can_stats->total_rx_match_ratio = (can_stats->matches * 100) /
-			can_stats->rx_frames;
+	if (pkg_stats->rx_frames)
+		pkg_stats->total_rx_match_ratio = (pkg_stats->matches * 100) /
+			pkg_stats->rx_frames;
 
-	can_stats->total_tx_rate = calc_rate(can_stats->jiffies_init, j,
-					    can_stats->tx_frames);
-	can_stats->total_rx_rate = calc_rate(can_stats->jiffies_init, j,
-					    can_stats->rx_frames);
+	pkg_stats->total_tx_rate = calc_rate(pkg_stats->jiffies_init, j,
+					    pkg_stats->tx_frames);
+	pkg_stats->total_rx_rate = calc_rate(pkg_stats->jiffies_init, j,
+					    pkg_stats->rx_frames);
 
 	/* calc current values */
-	if (can_stats->rx_frames_delta)
-		can_stats->current_rx_match_ratio =
-			(can_stats->matches_delta * 100) /
-			can_stats->rx_frames_delta;
+	if (pkg_stats->rx_frames_delta)
+		pkg_stats->current_rx_match_ratio =
+			(pkg_stats->matches_delta * 100) /
+			pkg_stats->rx_frames_delta;
 
-	can_stats->current_tx_rate = calc_rate(0, HZ, can_stats->tx_frames_delta);
-	can_stats->current_rx_rate = calc_rate(0, HZ, can_stats->rx_frames_delta);
+	pkg_stats->current_tx_rate = calc_rate(0, HZ, pkg_stats->tx_frames_delta);
+	pkg_stats->current_rx_rate = calc_rate(0, HZ, pkg_stats->rx_frames_delta);
 
 	/* check / update maximum values */
-	if (can_stats->max_tx_rate < can_stats->current_tx_rate)
-		can_stats->max_tx_rate = can_stats->current_tx_rate;
+	if (pkg_stats->max_tx_rate < pkg_stats->current_tx_rate)
+		pkg_stats->max_tx_rate = pkg_stats->current_tx_rate;
 
-	if (can_stats->max_rx_rate < can_stats->current_rx_rate)
-		can_stats->max_rx_rate = can_stats->current_rx_rate;
+	if (pkg_stats->max_rx_rate < pkg_stats->current_rx_rate)
+		pkg_stats->max_rx_rate = pkg_stats->current_rx_rate;
 
-	if (can_stats->max_rx_match_ratio < can_stats->current_rx_match_ratio)
-		can_stats->max_rx_match_ratio = can_stats->current_rx_match_ratio;
+	if (pkg_stats->max_rx_match_ratio < pkg_stats->current_rx_match_ratio)
+		pkg_stats->max_rx_match_ratio = pkg_stats->current_rx_match_ratio;
 
 	/* clear values for 'current rate' calculation */
-	can_stats->tx_frames_delta = 0;
-	can_stats->rx_frames_delta = 0;
-	can_stats->matches_delta   = 0;
+	pkg_stats->tx_frames_delta = 0;
+	pkg_stats->rx_frames_delta = 0;
+	pkg_stats->matches_delta   = 0;
 
 	/* restart timer (one second) */
-	mod_timer(&net->can.can_stattimer, round_jiffies(jiffies + HZ));
+	mod_timer(&net->can.stattimer, round_jiffies(jiffies + HZ));
 }
 
 /*
···
 static int can_stats_proc_show(struct seq_file *m, void *v)
 {
 	struct net *net = m->private;
-	struct s_stats *can_stats = net->can.can_stats;
-	struct s_pstats *can_pstats = net->can.can_pstats;
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
 
 	seq_putc(m, '\n');
-	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats->tx_frames);
-	seq_printf(m, " %8ld received frames (RXF)\n", can_stats->rx_frames);
-	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats->matches);
+	seq_printf(m, " %8ld transmitted frames (TXF)\n", pkg_stats->tx_frames);
+	seq_printf(m, " %8ld received frames (RXF)\n", pkg_stats->rx_frames);
+	seq_printf(m, " %8ld matched frames (RXMF)\n", pkg_stats->matches);
 
 	seq_putc(m, '\n');
 
-	if (net->can.can_stattimer.function == can_stat_update) {
+	if (net->can.stattimer.function == can_stat_update) {
 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
-				can_stats->total_rx_match_ratio);
+				pkg_stats->total_rx_match_ratio);
 
 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
-				can_stats->total_tx_rate);
+				pkg_stats->total_tx_rate);
 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
-				can_stats->total_rx_rate);
+				pkg_stats->total_rx_rate);
 
 		seq_putc(m, '\n');
 
 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
-				can_stats->current_rx_match_ratio);
+				pkg_stats->current_rx_match_ratio);
 
 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
-				can_stats->current_tx_rate);
+				pkg_stats->current_tx_rate);
 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
-				can_stats->current_rx_rate);
+				pkg_stats->current_rx_rate);
 
 		seq_putc(m, '\n');
 
 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
-				can_stats->max_rx_match_ratio);
+				pkg_stats->max_rx_match_ratio);
 
 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
-				can_stats->max_tx_rate);
+				pkg_stats->max_tx_rate);
 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
-				can_stats->max_rx_rate);
+				pkg_stats->max_rx_rate);
 
 		seq_putc(m, '\n');
 	}
 
 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
-			can_pstats->rcv_entries);
+			rcv_lists_stats->rcv_entries);
 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
-			can_pstats->rcv_entries_max);
+			rcv_lists_stats->rcv_entries_max);
 
-	if (can_pstats->stats_reset)
+	if (rcv_lists_stats->stats_reset)
 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
-				can_pstats->stats_reset);
+				rcv_lists_stats->stats_reset);
 
-	if (can_pstats->user_reset)
+	if (rcv_lists_stats->user_reset)
 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
-				can_pstats->user_reset);
+				rcv_lists_stats->user_reset);
 
 	seq_putc(m, '\n');
 	return 0;
···
 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
 {
 	struct net *net = m->private;
-	struct s_pstats *can_pstats = net->can.can_pstats;
-	struct s_stats *can_stats = net->can.can_stats;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
 
 	user_reset = 1;
 
-	if (net->can.can_stattimer.function == can_stat_update) {
+	if (net->can.stattimer.function == can_stat_update) {
 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
-				can_pstats->stats_reset + 1);
+				rcv_lists_stats->stats_reset + 1);
 	} else {
-		if (can_stats->jiffies_init != jiffies)
+		if (pkg_stats->jiffies_init != jiffies)
 			can_init_stats(net);
 
 		seq_printf(m, "Performed statistic reset #%ld.\n",
-				can_pstats->stats_reset);
+				rcv_lists_stats->stats_reset);
 	}
 	return 0;
 }
···
 
 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
 					     struct net_device *dev,
-					     struct can_dev_rcv_lists *d)
+					     struct can_dev_rcv_lists *dev_rcv_lists)
 {
-	if (!hlist_empty(&d->rx[idx])) {
+	if (!hlist_empty(&dev_rcv_lists->rx[idx])) {
 		can_print_recv_banner(m);
-		can_print_rcvlist(m, &d->rx[idx], dev);
+		can_print_rcvlist(m, &dev_rcv_lists->rx[idx], dev);
 	} else
 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
 
···
 	/* double cast to prevent GCC warning */
 	int idx = (int)(long)PDE_DATA(m->file->f_inode);
 	struct net_device *dev;
-	struct can_dev_rcv_lists *d;
+	struct can_dev_rcv_lists *dev_rcv_lists;
 	struct net *net = m->private;
 
 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
···
 	rcu_read_lock();
 
 	/* receive list for 'all' CAN devices (dev == NULL) */
-	d = net->can.can_rx_alldev_list;
-	can_rcvlist_proc_show_one(m, idx, NULL, d);
+	dev_rcv_lists = net->can.rx_alldev_list;
+	can_rcvlist_proc_show_one(m, idx, NULL, dev_rcv_lists);
 
 	/* receive list for registered CAN devices */
 	for_each_netdev_rcu(net, dev) {
···
 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
 {
 	struct net_device *dev;
-	struct can_dev_rcv_lists *d;
+	struct can_dev_rcv_lists *dev_rcv_lists;
 	struct net *net = m->private;
 
 	/* RX_SFF */
···
 	rcu_read_lock();
 
 	/* sff receive list for 'all' CAN devices (dev == NULL) */
-	d = net->can.can_rx_alldev_list;
-	can_rcvlist_proc_show_array(m, NULL, d->rx_sff, ARRAY_SIZE(d->rx_sff));
+	dev_rcv_lists = net->can.rx_alldev_list;
+	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_sff,
+				    ARRAY_SIZE(dev_rcv_lists->rx_sff));
 
 	/* sff receive list for registered CAN devices */
 	for_each_netdev_rcu(net, dev) {
 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
-			d = dev->ml_priv;
-			can_rcvlist_proc_show_array(m, dev, d->rx_sff,
-						    ARRAY_SIZE(d->rx_sff));
+			dev_rcv_lists = dev->ml_priv;
+			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_sff,
+						    ARRAY_SIZE(dev_rcv_lists->rx_sff));
 		}
 	}
 
···
 static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
 {
 	struct net_device *dev;
-	struct can_dev_rcv_lists *d;
+	struct can_dev_rcv_lists *dev_rcv_lists;
 	struct net *net = m->private;
 
 	/* RX_EFF */
···
 	rcu_read_lock();
 
 	/* eff receive list for 'all' CAN devices (dev == NULL) */
-	d = net->can.can_rx_alldev_list;
-	can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff));
+	dev_rcv_lists = net->can.rx_alldev_list;
+	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_eff,
+				    ARRAY_SIZE(dev_rcv_lists->rx_eff));
 
 	/* eff receive list for registered CAN devices */
 	for_each_netdev_rcu(net, dev) {
 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
-			d = dev->ml_priv;
-			can_rcvlist_proc_show_array(m, dev, d->rx_eff,
-						    ARRAY_SIZE(d->rx_eff));
+			dev_rcv_lists = dev->ml_priv;
+			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_eff,
+						    ARRAY_SIZE(dev_rcv_lists->rx_eff));
 		}
 	}
 

net/can/raw.c

···
 	int err = 0;
 	int notify_enetdown = 0;
 
-	if (len < sizeof(*addr))
+	if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex))
 		return -EINVAL;
 	if (addr->can_family != AF_CAN)
 		return -EINVAL;
···
 	if (msg->msg_name) {
 		DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
 
-		if (msg->msg_namelen < sizeof(*addr))
+		if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex))
 			return -EINVAL;
 
 		if (addr->can_family != AF_CAN)