This patch adds a netlink interface to configure the CAN bus termination of
CAN interfaces.

Inside the driver an array of supported termination values is defined:

const u16 drvname_termination[] = { 60, 120, CAN_TERMINATION_DISABLED };

struct drvname_priv *priv;
priv = netdev_priv(dev);

priv->termination_const = drvname_termination;
priv->termination_const_cnt = ARRAY_SIZE(drvname_termination);
priv->termination = CAN_TERMINATION_DISABLED;

And the funtion to set the value has to be defined:

priv->do_set_termination = drvname_set_termination;
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Reviewed-by: NRamesh Shanmugasundaram <Ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

A timer was used to restart after the bus-off state, leading to a
relatively large can_restart() executed in an interrupt context,
which in turn sets up pinctrl. When this happens during system boot,
there is a high probability of grabbing the pinctrl_list_mutex,
which is locked already by the probe() of other device, making the
kernel suspect a deadlock condition [1].

To resolve this issue, the restart_timer is replaced by a delayed
work.

[1] https://github.com/victronenergy/venus/issues/24Signed-off-by: NSergei Miroshnichenko <sergeimir@emcraft.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

For 'real' hardware CAN devices the netlink interface is used to set CAN
specific communication parameters. Real CAN hardware can not be created nor
removed with the ip tool ...

This patch adds a private dellink function for the CAN device driver interface
that does just nothing.

It's a follow up to commit 993e6f2f ("can: fix oops caused by wrong rtnl
newlink usage") but for dellink.
Reported-by: Najneu <ajneu1@gmail.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

With upstream commit bb208f14 (can: fix handling of unmodifiable
configuration options) a new can_validate() function was introduced.

When invoking 'ip link set can0 type can' without any configuration data
can_validate() tries to validate the content without taking into account that
there's totally no content. This patch adds a check for missing content.
Reported-by: Najneu <ajneu1@gmail.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch optimizes the calculation of the sample point. To understand what it
does have a look at the original implementation.

If there is a combination of timing parameters where both the bitrate and
sample point error are 0 the current implementation will find it.

However if the reference clock doesn't allow an optimal bitrate (this means the
bitrate error is always != 0) there might be several timing parameter
combinations having the same bitrate error. The original implementation will
allways choose the one with the highest brp. The actual sample point error
isn't taken into account.

This patch changes the algorithm to minimize the sample point error, too. Now a
brp/tseg combination is accepted as better if one of these condition are
fulfilled:
1) the bit rate error must be smaller, or
2) the bit rate error must be equal and
   the sample point error must be equal or smaller

If a smaller bit rate error is found the sample point error is reset. This
ensures that we first optimize for small bit rate error and then for small
sample point errors.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

As described in 'can: m_can: tag current CAN FD controllers as non-ISO'
(6cfda7fb) it is possible to define fixed configuration options by
setting the according bit in 'ctrlmode' and clear it in 'ctrlmode_supported'.
This leads to the incovenience that the fixed configuration bits can not be
passed by netlink even when they have the correct values (e.g. non-ISO, FD).

This patch fixes that issue and not only allows fixed set bit values to be set
again but now requires(!) to provide these fixed values at configuration time.
A valid CAN FD configuration consists of a nominal/arbitration bittiming, a
data bittiming and a control mode with CAN_CTRLMODE_FD set - which is now
enforced by a new can_validate() function. This fix additionally removed the
inconsistency that was prohibiting the support of 'CANFD-only' controller
drivers, like the RCar CAN FD.

For this reason a new helper can_set_static_ctrlmode() has been introduced to
provide a proper interface to handle static enabled CAN controller options.
Reported-by: NRamesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Reviewed-by: NRamesh Shanmugasundaram  <ramesh.shanmugasundaram@bp.renesas.com>
Cc: <stable@vger.kernel.org> # >= 3.18
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The sizeof() is invoked on an incorrect variable, likely due to some
copy-paste error, and this might result in memory corruption. Fix this.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: netdev@vger.kernel.org
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Commit 514ac99c "can: fix multiple delivery of a single CAN frame for
overlapping CAN filters" requires the skb->tstamp to be set to check for
identical CAN skbs.

Without timestamping to be required by user space applications this timestamp
was not generated which lead to commit 36c01245 "can: fix loss of CAN frames
in raw_rcv" - which forces the timestamp to be set in all CAN related skbuffs
by introducing several __net_timestamp() calls.

This forces e.g. out of tree drivers which are not using alloc_can{,fd}_skb()
to add __net_timestamp() after skbuff creation to prevent the frame loss fixed
in mainline Linux.

This patch removes the timestamp dependency and uses an atomic counter to
create an unique identifier together with the skbuff pointer.

Btw: the new skbcnt element introduced in struct can_skb_priv has to be
initialized with zero in out-of-tree drivers which are not using
alloc_can{,fd}_skb() too.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

As reported by Manfred Schlaegl here

   http://marc.info/?l=linux-netdev&m=143482089824232&w=2

commit 514ac99c "can: fix multiple delivery of a single CAN frame for
overlapping CAN filters" requires the skb->tstamp to be set to check for
identical CAN skbs.

As net timestamping is influenced by several players (netstamp_needed and
netdev_tstamp_prequeue) Manfred missed a proper timestamp which leads to
CAN frame loss.

As skb timestamping became now mandatory for CAN related skbs this patch
makes sure that received CAN skbs always have a proper timestamp set.
Maybe there's a better solution in the future but this patch fixes the
CAN frame loss so far.
Reported-by: NManfred Schlaegl <manfred.schlaegl@gmx.at>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

When accessing CAN network interfaces with AF_PACKET sockets e.g. by dhclient
this can lead to a skb_under_panic due to missing skb initialisations.

Add the missing initialisations at the CAN skbuff creation times on driver
level (rx path) and in the network layer (tx path).
Reported-by: NAustin Schuh <austin@peloton-tech.com>
Reported-by: NDaniel Steer <daniel.steer@mclaren.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/dev.c:294:2-3: Unneeded semicolon

 Removes unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Cc: Andri Yngvason <andri.yngvason@marel.com>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

In order to be able to move the stats increment from can_bus_off() into
can_change_state(), the increment had to be moved back into code that was using
can_bus_off() but not can_change_state().

As a side-effect, this patch fixes the following bugs:
 * Redundant call to can_bus_off() in c_can.
 * Bus-off counted twice in xilinx_can.
Signed-off-by: NAndri Yngvason <andri.yngvason@marel.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

When changing flags in the CAN drivers ctrlmode the provided new content has to
be checked whether the bits are allowed to be changed. The bits that are to be
changed are given as a bitfield in cm->mask. Therefore checking against
cm->flags is wrong as the content can hold any kind of values.

The iproute2 tool sets the bits in cm->mask and cm->flags depending on the
detected command line options. To be robust against bogus user space
applications additionally sanitize the provided flags with the provided mask.

Cc: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The handling of can error states is different between platforms.
This is an attempt to correct that problem.

I've moved this handling into a generic function for changing the
error state. This ensures that error state changes are handled
the same way everywhere (where this function is used).

This new mechanism also adds reverse state transitioning in error
frames, i.e. the user will be notified through the socket interface
when the state goes down.
Signed-off-by: NAndri Yngvason <andri.yngvason@marel.com>
Acked-by: NWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch fixes a typo in CAN's dev.c:

    CIA -> CiA

which stands for CAN in Automation.
Signed-off-by: NRoman Fietze <roman.fietze@telemotive.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

ikfree_skb() is Called in can_free_echo_skb(), which might be called from (TX
Error) interrupt, which triggers the folloing warning:

[ 1153.360705] ------------[ cut here ]------------
[ 1153.360715] WARNING: CPU: 0 PID: 31 at net/core/skbuff.c:563 skb_release_head_state+0xb9/0xd0()
[ 1153.360772] Call Trace:
[ 1153.360778]  [<c167906f>] dump_stack+0x41/0x52
[ 1153.360782]  [<c105bb7e>] warn_slowpath_common+0x7e/0xa0
[ 1153.360784]  [<c158b909>] ? skb_release_head_state+0xb9/0xd0
[ 1153.360786]  [<c158b909>] ? skb_release_head_state+0xb9/0xd0
[ 1153.360788]  [<c105bc42>] warn_slowpath_null+0x22/0x30
[ 1153.360791]  [<c158b909>] skb_release_head_state+0xb9/0xd0
[ 1153.360793]  [<c158be90>] skb_release_all+0x10/0x30
[ 1153.360795]  [<c158bf06>] kfree_skb+0x36/0x80
[ 1153.360799]  [<f8486938>] ? can_free_echo_skb+0x28/0x40 [can_dev]
[ 1153.360802]  [<f8486938>] can_free_echo_skb+0x28/0x40 [can_dev]
[ 1153.360805]  [<f849a12c>] esd_pci402_interrupt+0x34c/0x57a [esd402]
[ 1153.360809]  [<c10a75b5>] handle_irq_event_percpu+0x35/0x180
[ 1153.360811]  [<c10a7623>] ? handle_irq_event_percpu+0xa3/0x180
[ 1153.360813]  [<c10a7731>] handle_irq_event+0x31/0x50
[ 1153.360816]  [<c10a9c7f>] handle_fasteoi_irq+0x6f/0x120
[ 1153.360818]  [<c10a9c10>] ? handle_edge_irq+0x110/0x110
[ 1153.360822]  [<c1011b61>] handle_irq+0x71/0x90
[ 1153.360823]  <IRQ>  [<c168152c>] do_IRQ+0x3c/0xd0
[ 1153.360829]  [<c1680b6c>] common_interrupt+0x2c/0x34
[ 1153.360834]  [<c107d277>] ? finish_task_switch+0x47/0xf0
[ 1153.360836]  [<c167c27b>] __schedule+0x35b/0x7e0
[ 1153.360839]  [<c10a5334>] ? console_unlock+0x2c4/0x4d0
[ 1153.360842]  [<c13df500>] ? n_tty_receive_buf_common+0x890/0x890
[ 1153.360845]  [<c10707b6>] ? process_one_work+0x196/0x370
[ 1153.360847]  [<c167c723>] schedule+0x23/0x60
[ 1153.360849]  [<c1070de1>] worker_thread+0x161/0x460
[ 1153.360852]  [<c1090fcf>] ? __wake_up_locked+0x1f/0x30
[ 1153.360854]  [<c1070c80>] ? rescuer_thread+0x2f0/0x2f0
[ 1153.360856]  [<c1074f01>] kthread+0xa1/0xc0
[ 1153.360859]  [<c1680401>] ret_from_kernel_thread+0x21/0x30
[ 1153.360861]  [<c1074e60>] ? kthread_create_on_node+0x110/0x110
[ 1153.360863] ---[ end trace 5ff83639cbb74b35 ]---

This patch replaces the kfree_skb() by dev_kfree_skb_any().
Signed-off-by: NThomas Körper <thomas.koerper@esd.eu>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

this patch removes best_rate variable from can_calc_bittiming()
function which was set but was never used.
Signed-off-by: NLad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert
all users to pass NET_NAME_UNKNOWN.

Coccinelle patch:

@@
expression sizeof_priv, name, setup, txqs, rxqs, count;
@@

(
-alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs)
+alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs)
|
-alloc_netdev_mq(sizeof_priv, name, setup, count)
+alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count)
|
-alloc_netdev(sizeof_priv, name, setup)
+alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup)
)

v9: move comments here from the wrong commit
Signed-off-by: NTom Gundersen <teg@jklm.no>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When trying to set a data bitrate on non CAN FD devices the 'ip' tool
answers with:

	RTNETLINK answers: Unknown error 524

Rename '-ENOTSUPP' to '-EOPNOTSUPP' so that 'ip' answers correctly:

       RTNETLINK answers: Operation not supported
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Additionally to have the second (data) bitrate available the data bitrate
has to be greater or equal to the arbitration bitrate in CAN FD.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The configuration for CAN FD depends on CAN_CTRLMODE_FD enabled in the driver
specific ctrlmode_supported capabilities.

The configuration can be done either with the 'fd { on | off }' option in the
'ip' tool from iproute2 or by setting the CAN netdevice MTU to CAN_MTU (16) or
to CANFD_MTU (72).
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

As CAN FD offers a second bitrate for the data section of the CAN frame the
infrastructure for storing and configuring this second bitrate is introduced.
Improved the readability of the if-statement by inserting some newlines.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

As the bittiming calculation functions are to be used with different
bittiming_const structures for CAN and CAN FD the direct reference to
priv->bittiming_const inside these functions has to be removed.

Also moved the check for existing bittiming const to one place.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch moves a sanity check in order to have a second user for CAN FD.
Also simplify the return value generation in can_get_bittiming() as only
correct return values of can_[calc|fixup]_bittiming() lead to a return value of
zero.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

When setting the bitrate both can_calc_bittiming() and can_fixup_bittiming()
lead to the bitrate variable to be set, when a proper bit timing is available.
Only then the bitrate configuration is stored for the device, so checking for
priv->bittiming.bitrate is always sufficient.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The skbuff protocol value was formerly fixed/sanitized to ETH_P_CAN in
can_put_echo_skb(). With CAN FD this value has to be preserved.
This patch changes the hard assignment of the protocol value to a check of
valid protocol values for CAN and CAN FD.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch adds the ability of allocating a CANFD frame data structure in the
skb data area.
Signed-off-by: NStephane Grosjean <s.grosjean@peak-system.com>
Acked-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Self generated skbuffs in net/can/bcm.c are setting a skb->sk reference but
no explicit destructor which is enforced since Linux 3.11 with commit
376c7311 (net: add a temporary sanity check in skb_orphan()).

This patch adds some helper functions to make sure that a destructor is
properly defined when a sock reference is assigned to a CAN related skb.
To create an unshared skb owned by the original sock a common helper function
has been introduced to replace open coded functions to create CAN echo skbs.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: NAndre Naujoks <nautsch2@gmail.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Wolfgang Grandegger <wg@grandegger.com>
CC: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch sorts the handling of data[IFLA_CAN_*] by IFLA_CAN_*.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch sorts the call to nla_put() by IFLA_CAN_*.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch sorts the individual addends of the sum by IFLA_CAN_*.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch fixes the calculation of the nlmsg size, by adding the missing
nla_total_size().
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added accessor and skb_reserve helpers for struct can_skb_priv.
Removed pointless skb_headroom() check.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
CC: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The struct can_skb_priv is used to transport additional information along
with the stored struct can(fd)_frame that can not be contained in existing
struct sk_buff elements.

can_skb_priv is located in the skb headroom, which does not touch the existing
CAN sk_buff usage with skb->data and skb->len, so that even out-of-tree
CAN drivers can be used without changes.

Btw. out-of-tree CAN drivers without can_skb_priv in the sk_buff headroom
would not support features based on can_skb_priv.

The can_skb_priv->ifindex contains the first interface where the CAN frame
appeared on the local host. Unfortunately skb->skb_iif can not be used as this
value is overwritten in every netif_receive_skb() call.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The LED trigger name for CAN devices is based on the initial
CAN device name, but does never change. The LED trigger name
is not guaranteed to be unique in case of hotplugging CAN devices.

This patch tries to address this problem by modifying the
LED trigger name according to the CAN device name when
the latter changes.

v1 - Kurt Van Dijck
v2 - Fabio Baltieri
- remove rename blocking if trigger is bound
- use led-subsystem function for the actual rename (still WiP)
- call init/exit functions from dev.c
v3 - Kurt Van Dijck
- safe operation for non-candev based devices (vcan, slcan)
	based on earlier patch
v4 - Kurt Van Dijck
- trivial patch mistakes fixed
Signed-off-by: NKurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: NFabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

In net_device notifier calls, it was impossible to determine
if a CAN device is based on candev in a safe way.
This patch adds such test in order to access candev storage
from within those notifiers.
Signed-off-by: NKurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NFabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

If the restart timer is running due to BUS-OFF and the device is
disconnected an dev_put will decrease the usage counter to -1 thus
blocking the interface removal, resulting in the following dmesg
lines repeating every 10s:
can: notifier: receive list not found for dev can0
can: notifier: receive list not found for dev can0
can: notifier: receive list not found for dev can0
unregister_netdevice: waiting for can0 to become free. Usage count = -1

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Make can_restart static to fix the following sparse warning:
drivers/net/can/dev.c:371:6: warning: symbol 'can_restart' was not
declared. Should it be static?
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

- update sanity checks
- add DLC to length conversion helpers
  - can_dlc2len() - get data length from can_dlc with sanitized can_dlc
  - can_len2dlc() - map the sanitized data length to an appropriate DLC
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>