can: canxl: add virtual CAN network identifier support

CAN XL data frames contain an 8-bit virtual CAN network identifier (VCID).
A VCID value of zero represents an 'untagged' CAN XL frame.

To receive and send these optional VCIDs via CAN_RAW sockets a new socket
option CAN_RAW_XL_VCID_OPTS is introduced to define/access VCID content:

- tx: set the outgoing VCID value by the kernel (one fixed 8-bit value)
- tx: pass through VCID values from the user space (e.g. for traffic replay)
- rx: apply VCID receive filter (value/mask) to be passed to the user space

With the 'tx pass through' option CAN_RAW_XL_VCID_TX_PASS all valid VCID
values can be sent, e.g. to replay full qualified CAN XL traffic.

The VCID value provided for the CAN_RAW_XL_VCID_TX_SET option will
override the VCID value in the struct canxl_frame.prio defined for
CAN_RAW_XL_VCID_TX_PASS when both flags are set.

With a rx_vcid_mask of zero all possible VCID values (0x00 - 0xFF) are
passed to the user space when the CAN_RAW_XL_VCID_RX_FILTER flag is set.
Without this flag only untagged CAN XL frames (VCID = 0x00) are delivered
to the user space (default).

The 8-bit VCID is stored inside the CAN XL prio element (only in CAN XL
frames!) to not interfere with other CAN content or the CAN filters
provided by the CAN_RAW sockets and kernel infrastruture.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20240212213550.18516-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: af_can: remove useless parameter 'err' in 'can_rx_register()'

Since commit bdfb5765e45b remove NULL-ptr checks from users of
can_dev_rcv_lists_find(). 'err' parameter is useless, so remove it.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/all/20221208090940.3695670-1-yebin@huaweicloud.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: fix NULL pointer dereference in can_rcv_filter

Analogue to commit 8aa59e355949 ("can: af_can: fix NULL pointer
dereference in can_rx_register()") we need to check for a missing
initialization of ml_priv in the receive path of CAN frames.

Since commit 4e096a18867a ("net: introduce CAN specific pointer in the
struct net_device") the check for dev->type to be ARPHRD_CAN is not
sufficient anymore since bonding or tun netdevices claim to be CAN
devices but do not initialize ml_priv accordingly.

Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device")
Reported-by: syzbot+2d7f58292cb5b29eb5ad@syzkaller.appspotmail.com
Reported-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20221206201259.3028-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: fix NULL pointer dereference in can_rx_register()

It causes NULL pointer dereference when testing as following:
(a) use syscall(__NR_socket, 0x10ul, 3ul, 0) to create netlink socket.
(b) use syscall(__NR_sendmsg, ...) to create bond link device and vxcan
link device, and bind vxcan device to bond device (can also use
ifenslave command to bind vxcan device to bond device).
(c) use syscall(__NR_socket, 0x1dul, 3ul, 1) to create CAN socket.
(d) use syscall(__NR_bind, ...) to bind the bond device to CAN socket.

The bond device invokes the can-raw protocol registration interface to
receive CAN packets. However, ml_priv is not allocated to the dev,
dev_rcv_lists is assigned to NULL in can_rx_register(). In this case,
it will occur the NULL pointer dereference issue.

The following is the stack information:
BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 122a4067 P4D 122a4067 PUD 1223c067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
RIP: 0010:can_rx_register+0x12d/0x1e0
Call Trace:
<TASK>
raw_enable_filters+0x8d/0x120
raw_enable_allfilters+0x3b/0x130
raw_bind+0x118/0x4f0
__sys_bind+0x163/0x1a0
__x64_sys_bind+0x1e/0x30
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>

Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/all/20221028085650.170470-1-shaozhengchao@huawei.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: can_exit(): add missing dev_remove_pack() of canxl_packet

In can_init(), dev_add_pack(&canxl_packet) is added but not removed in
can_exit(). It breaks the packet handler list and can make kernel
panic when can_init() is called for the second time.

| > modprobe can && rmmod can
| > rmmod xxx && modprobe can
|
| BUG: unable to handle page fault for address: fffffbfff807d7f4
| RIP: 0010:dev_add_pack+0x133/0x1f0
| Call Trace:
| <TASK>
| can_init+0xaa/0x1000 [can]
| do_one_initcall+0xd3/0x4e0
| ...

Fixes: fb08cba12b52 ("can: canxl: update CAN infrastructure for CAN XL frames")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20221031033053.37849-1-chenzhongjin@huawei.com
[mkl: adjust subject and commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: canxl: update CAN infrastructure for CAN XL frames

- add new ETH_P_CANXL ethernet protocol type
- update skb checks for CAN XL
- add alloc_canxl_skb() which now needs a data length parameter
- introduce init_can_skb_reserve() to reduce code duplication

Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-6-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: set CANFD_FDF flag in all CAN FD frame structures

To simplify the testing in user space all struct canfd_frame's provided by
the CAN subsystem of the Linux kernel now have the CANFD_FDF flag set in
canfd_frame::flags.

NB: Handcrafted ETH_P_CANFD frames introduced via PF_PACKET socket might
not set this bit correctly. During the check for sufficient headroom in
PF_PACKET sk_buffs the uninitialized CAN sk_buff data structures are filled.
In the case of a CAN FD frame the CANFD_FDF flag is set accordingly.

As the CAN frame content is already zero initialized in alloc_canfd_skb()
the obsolete initialization of cf->flags in the CTU CAN FD driver has been
removed as it would overwrite the already set CANFD_FDF flag.

Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-4-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: skb: unify skb CAN frame identification helpers

Replace open coded checks for sk_buffs containing Classical CAN and
CAN FD frame structures as a preparation for CAN XL support.

With the added length check the unintended processing of CAN XL frames
having the CANXL_XLF bit set can be suppressed even when the skb->len
fits to non CAN XL frames.

The CAN_RAW socket needs a rework to use these helpers. Therefore the
use of these helpers is postponed to the CAN_RAW CAN XL integration.

The J1939 protocol gets a check for Classical CAN frames too.

Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: Use netif_rx().

Since commit
baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.")

the function netif_rx() can be used in preemptible/thread context as
well as in interrupt context.

Use netif_rx().

Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: linux-can@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce CAN specific pointer in the struct net_device

Since 20dd3850bcf8 ("can: Speed up CAN frame receiption by using
ml_priv") the CAN framework uses per device specific data in the AF_CAN
protocol. For this purpose the struct net_device->ml_priv is used. Later
the ml_priv usage in CAN was extended for other users, one of them being
CAN_J1939.

Later in the kernel ml_priv was converted to an union, used by other
drivers. E.g. the tun driver started storing it's stats pointer.

Since tun devices can claim to be a CAN device, CAN specific protocols
will wrongly interpret this pointer, which will cause system crashes.
Mostly this issue is visible in the CAN_J1939 stack.

To fix this issue, we request a dedicated CAN pointer within the
net_device struct.

Reported-by: syzbot+5138c4dd15a0401bec7b@syzkaller.appspotmail.com
Fixes: 20dd3850bcf8 ("can: Speed up CAN frame receiption by using ml_priv")
Fixes: ffd956eef69b ("can: introduce CAN midlayer private and allocate it automatically")
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Fixes: 497a5757ce4e ("tun: switch to net core provided statistics counters")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210223070127.4538-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

can: af_can: can_rx_unregister(): remove WARN() statement from list operation sanity check

To detect potential bugs in CAN protocol implementations (double removal of
receiver entries) a WARN() statement has been used if no matching list item was
found for removal.

The fault injection issued by syzkaller was able to create a situation where
the closing of a socket runs simultaneously to the notifier call chain for
removing the CAN network device in use.

This case is very unlikely in real life but it doesn't break anything.
Therefore we just replace the WARN() statement with pr_warn() to preserve the
notification for the CAN protocol development.

Reported-by: syzbot+381d06e0c8eaacb8706f@syzkaller.appspotmail.com
Reported-by: syzbot+d0ddd88c9a7432f041e6@syzkaller.appspotmail.com
Reported-by: syzbot+76d62d3b8162883c7d11@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201126192140.14350-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: replace can_dlc as variable/element for payload length

The naming of can_dlc as element of struct can_frame and also as variable
name is misleading as it claims to be a 'data length CODE' but in reality
it always was a plain data length.

With the indroduction of a new 'len' element in struct can_frame we can now
remove can_dlc as name and make clear which of the former uses was a plain
length (-> 'len') or a data length code (-> 'dlc') value.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201120100444.3199-1-socketcan@hartkopp.net
[mkl: gs_usb: keep struct gs_host_frame::can_dlc as is]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: prevent potential access of uninitialized member in canfd_rcv()

In canfd_rcv(), cfd->len is uninitialized when skb->len = 0, and this
uninitialized cfd->len is accessed nonetheless by pr_warn_once().

Fix this uninitialized variable access by checking cfd->len's validity
condition (cfd->len > CANFD_MAX_DLEN) separately after the skb->len's
condition is checked, and appropriately modify the log messages that
are generated as well.
In case either of the required conditions fail, the skb is freed and
NET_RX_DROP is returned, same as before.

Fixes: d4689846881d ("can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once")
Reported-by: syzbot+9bcb0c9409066696d3aa@syzkaller.appspotmail.com
Tested-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Link: https://lore.kernel.org/r/20201103213906.24219-3-anant.thazhemadam@gmail.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: prevent potential access of uninitialized member in can_rcv()

In can_rcv(), cfd->len is uninitialized when skb->len = 0, and this
uninitialized cfd->len is accessed nonetheless by pr_warn_once().

Fix this uninitialized variable access by checking cfd->len's validity
condition (cfd->len > CAN_MAX_DLEN) separately after the skb->len's
condition is checked, and appropriately modify the log messages that
are generated as well.
In case either of the required conditions fail, the skb is freed and
NET_RX_DROP is returned, same as before.

Fixes: 8cb68751c115 ("can: af_can: can_rcv(): replace WARN_ONCE by pr_warn_once")
Reported-by: syzbot+9bcb0c9409066696d3aa@syzkaller.appspotmail.com
Tested-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Link: https://lore.kernel.org/r/20201103213906.24219-2-anant.thazhemadam@gmail.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: remove obsolete version strings

As pointed out by Jakub Kicinski here:
http://lore.kernel.org/r/20201009175751.5c54097f@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com
this patch removes the obsolete version information of the different
CAN protocols and the AF_CAN core module.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201012074354.25839-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: can_rcv_list_find(): fix kernel doc after variable renaming

This patch fixes the kernel doc for can_rcv_list_find() which was broken in commit:

3ee6d2bebef8 ("can: af_can: rename find_rcv_list() to can_rcv_list_find()")

while renaming a variable, but forgetting to rename the kernel doc, too.

Link: http://lore.kernel.org/r/20201006203748.1750156-2-mkl@pengutronix.de
Fixes: 3ee6d2bebef8 ("can: af_can: rename find_rcv_list() to can_rcv_list_find()")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: net: fix spelling mistakes

This patch fixes spelling erros found by "codespell" in the net/can
subtree.

Link: https://lore.kernel.org/r/20200915223527.1417033-5-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: can: kerneldoc fixes

Simple fixes which require no deep knowledge of the code.

Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: af_can: export can_sock_destruct()

In j1939 we need our own struct sock::sk_destruct callback. Export the
generic af_can can_sock_destruct() that allows us to chain-call it.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

can: af_can: use spin_lock_bh() for &net->can.rcvlists_lock

The can_rx_unregister() can be called from NAPI (soft IRQ) context, at least
by j1939 stack. This leads to potential dead lock with &net->can.rcvlists_lock
called from can_rx_register:
===============================================================================
WARNING: inconsistent lock state
4.19.0-20181029-1-g3e67f95ba0d3 #3 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
testj1939/224 [HC0[0]:SC1[1]:HE1:SE0] takes:
1ad0fda3 (&(&net->can.rcvlists_lock)->rlock){+.?.}, at: can_rx_unregister+0x4c/0x1ac
{SOFTIRQ-ON-W} state was registered at:
lock_acquire+0xd0/0x1f4
_raw_spin_lock+0x30/0x40
can_rx_register+0x5c/0x14c
j1939_netdev_start+0xdc/0x1f8
j1939_sk_bind+0x18c/0x1c8
__sys_bind+0x70/0xb0
sys_bind+0x10/0x14
ret_fast_syscall+0x0/0x28
0xbedc9b64
irq event stamp: 2440
hardirqs last enabled at (2440): [<c01302c0>] __local_bh_enable_ip+0xac/0x184
hardirqs last disabled at (2439): [<c0130274>] __local_bh_enable_ip+0x60/0x184
softirqs last enabled at (2412): [<c08b0bf4>] release_sock+0x84/0xa4
softirqs last disabled at (2415): [<c013055c>] irq_exit+0x100/0x1b0

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&(&net->can.rcvlists_lock)->rlock);
<Interrupt>
lock(&(&net->can.rcvlists_lock)->rlock);

*** DEADLOCK ***

2 locks held by testj1939/224:
#0: 168eb13b (rcu_read_lock){....}, at: netif_receive_skb_internal+0x3c/0x350
#1: 168eb13b (rcu_read_lock){....}, at: can_receive+0x88/0x1c0
===============================================================================

To avoid this situation, we should use spin_lock_bh() instead of spin_lock().

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: remove NULL-ptr checks from users of can_dev_rcv_lists_find()

Since using the "struct can_ml_priv" for the per device "struct
dev_rcv_lists" the call can_dev_rcv_lists_find() cannot fail anymore.
This patch simplifies af_can by removing the NULL pointer checks from
the dev_rcv_lists returned by can_dev_rcv_lists_find().

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: make use of preallocated can_ml_priv for per device struct can_dev_rcv_lists

This patch removes the old method of allocating the per device protocol
specific memory via a netdevice_notifier. This had the drawback, that
the allocation can fail, leading to a lot of null pointer checks in the
code. This also makes the live cycle management of this memory quite
complicated.

This patch switches from the allocating the struct can_dev_rcv_lists in
a NETDEV_REGISTER call to using the dev->ml_priv, which is allocated by
the driver since the previous patch.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: introduce CAN midlayer private and allocate it automatically

This patch introduces the CAN midlayer private structure ("struct
can_ml_priv") which should be used to hold protocol specific per device
data structures. For now it's only member is "struct can_dev_rcv_lists".

The CAN midlayer private is allocated via alloc_netdev()'s private and
assigned to "struct net_device::ml_priv" during device creation. This is
done transparently for CAN drivers using alloc_candev(). The slcan, vcan
and vxcan drivers which are not using alloc_candev() have been adopted
manually. The memory layout of the netdev_priv allocated via
alloc_candev() will looke like this:

+-------------------------+
| driver's priv |
+-------------------------+
| struct can_ml_priv |
+-------------------------+
| array of struct sk_buff |
+-------------------------+

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: can_pernet_exit(): no need to iterate over and cleanup registered CAN devices

The networking core takes care and unregisters every network device in
a namespace before calling the can_pernet_exit() hook. This patch
removes the unneeded cleanup.

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Suggested-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: can_rx_register(): use max() instead of open coding it

This patch replaces an open coded max by the proper kernel define max().

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: give variable holding the CAN receiver and the receiver list a sensible name

This patch gives the variables holding the CAN receiver and the receiver
list a better name by renaming them from "r to "rcv" and "rl" to
"recv_list".

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: rename find_dev_rcv_lists() to can_dev_rcv_lists_find()

This patch add the commonly used prefix "can_" to the find_dev_rcv_lists()
function and moves the "find" to the end, as the function returns a struct
can_dev_rcv_list. This improves the overall readability of the code.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: rename find_rcv_list() to can_rcv_list_find()

This patch add the commonly used prefix "can_" to the find_rcv_list()
function and add the "find" to the end, as the function returns a struct
rcv_list. This improves the overall readability of the code.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: give variable holding the CAN per device receive lists a sensible name

This patch gives the variables holding the CAN receive filter lists a
better name by renaming them from "d" to "dev_rcv_lists".

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: netns: remove "can_" prefix from members struct netns_can

This patch improves the code reability by removing the redundant "can_"
prefix from the members of struct netns_can (as the struct netns_can itself
is the member "can" of the struct net.)

The conversion is done with:

sed -i \
-e "s/struct can_dev_rcv_lists \*can_rx_alldev_list;/struct can_dev_rcv_lists *rx_alldev_list;/" \
-e "s/spinlock_t can_rcvlists_lock;/spinlock_t rcvlists_lock;/" \
-e "s/struct timer_list can_stattimer;/struct timer_list stattimer; /" \
-e "s/can\.can_rx_alldev_list/can.rx_alldev_list/g" \
-e "s/can\.can_rcvlists_lock/can.rcvlists_lock/g" \
-e "s/can\.can_stattimer/can.stattimer/g" \
include/net/netns/can.h \
net/can/*.[ch]

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: give variables holding CAN statistics a sensible name

This patch rename the variables holding the CAN statistics (can_stats
and can_pstats) to pkg_stats and rcv_lists_stats which reflect better
their meaning.

The conversion is done with:

sed -i \
-e "s/can_stats\([^_]\)/pkg_stats\1/g" \
-e "s/can_pstats/rcv_lists_stats/g" \
net/can/af_can.c

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: netns: give members of struct netns_can holding the statistics a sensible name

This patch gives the members of the struct netns_can that are holding
the statistics a sensible name, by renaming struct netns_can::can_stats
into struct netns_can::pkg_stats and struct netns_can::can_pstats into
struct netns_can::rcv_lists_stats.

The conversion is done with:

sed -i \
-e "s:\(struct[^*]*\*\)can_stats;.*:\1pkg_stats;:" \
-e "s:\(struct[^*]*\*\)can_pstats;.*:\1rcv_lists_stats;:" \
-e "s/can\.can_stats/can.pkg_stats/g" \
-e "s/can\.can_pstats/can.rcv_lists_stats/g" \
net/can/*.[ch] \
include/net/netns/can.h

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: netns: give structs holding the CAN statistics a sensible name

This patch renames both "struct s_stats" and "struct s_pstats", to
"struct can_pkg_stats" and "struct can_rcv_lists_stats" to better
reflect their meaning and improve code readability.

The conversion is done with:

sed -i \
-e "s/struct s_stats/struct can_pkg_stats/g" \
-e "s/struct s_pstats/struct can_rcv_lists_stats/g" \
net/can/*.[ch] \
include/net/netns/can.h

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: can_pernet_init(): Use preferred style kzalloc(sizeof()) usage

This patch switches can_pernet_init() to the preferred style of using
the sizeof() operator in kzalloc().

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: avoid splitting quoted string across lines

This patch joins all error message strings in af_can to be in single
lines, to ease searching for them.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: fix alignment

This patch fixes the alignment of find_dev_rcv_lists() and canfd_rcv()
so that checkpatch doesn't complain anymore.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: balance braces around else statements

This patch balances the braces around else statements, so that
checkpatch doesn't complain anymore.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: convert block comments to network style comments

This patch converts all block comments to network subsystem style block
comments.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: Add SPDX license identifiers for CAN subsystem

Add missing SPDX identifiers for the CAN network layer and correct the SPDX
license for two of its include files to make sure the BSD-3-Clause applies
for the entire subsystem.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: remove obsolete empty ioctl() handler

With commit c7cbdbf29f488a ("net: rework SIOCGSTAMP ioctl handling") the only
ioctl function in can_ioctl() has been removed.

As this SIOCGSTAMP ioctl command is now handled in net/socket.c we can entirely
remove the CAN specific ioctl functions.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: purge socket error queue on sock destruct

CAN supports software tx timestamps as of the below commit. Purge
any queued timestamp packets on socket destroy.

Fixes: 51f31cabe3ce ("ip: support for TX timestamps on UDP and RAW sockets")
Reported-by: syzbot+a90604060cb40f5bdd16@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: Fix error path of can_init()

This patch add error path for can_init() to avoid possible crash if some
error occurs.

Fixes: 0d66548a10cb ("[CAN]: Add PF_CAN core module")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: rework SIOCGSTAMP ioctl handling

The SIOCGSTAMP/SIOCGSTAMPNS ioctl commands are implemented by many
socket protocol handlers, and all of those end up calling the same
sock_get_timestamp()/sock_get_timestampns() helper functions, which
results in a lot of duplicate code.

With the introduction of 64-bit time_t on 32-bit architectures, this
gets worse, as we then need four different ioctl commands in each
socket protocol implementation.

To simplify that, let's add a new .gettstamp() operation in
struct proto_ops, and move ioctl implementation into the common
sock_ioctl()/compat_sock_ioctl_trans() functions that these all go
through.

We can reuse the sock_get_timestamp() implementation, but generalize
it so it can deal with both native and compat mode, as well as
timeval and timespec structures.

Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/lkml/CAK8P3a038aDQQotzua_QtKGhq8O9n+rdiz2=WDCp82ys8eUT+A@mail.gmail.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Revert recent Spectre-v1 patches.

This reverts:

50d5258634ae ("net: core: Fix Spectre v1 vulnerability")
d686026b1e6e ("phonet: af_phonet: Fix Spectre v1 vulnerability")
a95386f0390a ("nfc: af_nfc: Fix Spectre v1 vulnerability")
a3ac5817ffe8 ("can: af_can: Fix Spectre v1 vulnerability")

After some discussion with Alexei Starovoitov these all seem to
be completely unnecessary.

Signed-off-by: David S. Miller <davem@davemloft.net>

can: af_can: Fix Spectre v1 vulnerability

protocol is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

net/can/af_can.c:115 can_get_proto() warn: potential spectre issue 'proto_tab' [w]

Fix this by sanitizing protocol before using it to index proto_tab.

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Drop pernet_operations::async

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Use octal not symbolic permissions

Prefer the direct use of octal for permissions.

Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace
and some typing.

Miscellanea:

o Whitespace neatening around these conversions.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Convert can_pernet_ops

These pernet_operations create and destroy /proc entries
and cancel per-net timer.

Also, there are unneed iterations over empty list of net
devices, since all net devices must be already moved
to init_net or unregistered by default_device_ops. This
already was mentioned here:

https://marc.info/?l=linux-can&m=150169589119335&w=2

So, it looks safe to make them async.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once

If an invalid CANFD frame is received, from a driver or from a tun
interface, a Kernel warning is generated.

This patch replaces the WARN_ONCE by a simple pr_warn_once, so that a
kernel, bootet with panic_on_warn, does not panic. A printk seems to be
more appropriate here.

Reported-by: syzbot+e3b775f40babeff6e68b@syzkaller.appspotmail.com
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: can_rcv(): replace WARN_ONCE by pr_warn_once

If an invalid CAN frame is received, from a driver or from a tun
interface, a Kernel warning is generated.

This patch replaces the WARN_ONCE by a simple pr_warn_once, so that a
kernel, bootet with panic_on_warn, does not panic. A printk seems to be
more appropriate here.

Reported-by: syzbot+4386709c0c1284dca827@syzkaller.appspotmail.com
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: give struct holding the CAN per device receive lists a sensible name

This patch adds a "can_" prefix to the "struct dev_rcv_lists" to better
reflect the meaning and improbe code readability.

The conversion is done with:

sed -i \
-e "s/struct dev_rcv_lists/struct can_dev_rcv_lists/g" \
net/can/*.[ch] include/net/netns/can.h

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: can_pernet_init(): add missing error handling for kzalloc returning NULL

This patch adds the missing check and error handling for out-of-memory
situations, when kzalloc cannot allocate memory.

Fixes: cb5635a36776 ("can: complete initial namespace support")
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: af_can: do not access proto_tab directly use rcu_access_pointer instead

"proto_tab" is a RCU protected array, when directly accessing the array,
sparse throws these warnings:

CHECK /srv/work/frogger/socketcan/linux/net/can/af_can.c
net/can/af_can.c:115:14: error: incompatible types in comparison expression (different address spaces)
net/can/af_can.c:795:17: error: incompatible types in comparison expression (different address spaces)
net/can/af_can.c:816:9: error: incompatible types in comparison expression (different address spaces)

This patch fixes the problem by using rcu_access_pointer() and
annotating "proto_tab" array as __rcu.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: can: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-can@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: af_can: namespace support: fix lockdep splat: properly initialize spin_lock

This patch uses spin_lock_init() instead of __SPIN_LOCK_UNLOCKED() to
initialize the per namespace net->can.can_rcvlists_lock lock to fix this
lockdep warning:

| INFO: trying to register non-static key.
| the code is fine but needs lockdep annotation.
| turning off the locking correctness validator.
| CPU: 0 PID: 186 Comm: candump Not tainted 4.12.0-rc3+ #47
| Hardware name: Marvell Kirkwood (Flattened Device Tree)
| [<c0016644>] (unwind_backtrace) from [<c00139a8>] (show_stack+0x18/0x1c)
| [<c00139a8>] (show_stack) from [<c0058c8c>] (register_lock_class+0x1e4/0x55c)
| [<c0058c8c>] (register_lock_class) from [<c005bdfc>] (__lock_acquire+0x148/0x1990)
| [<c005bdfc>] (__lock_acquire) from [<c005deec>] (lock_acquire+0x174/0x210)
| [<c005deec>] (lock_acquire) from [<c04a6780>] (_raw_spin_lock+0x50/0x88)
| [<c04a6780>] (_raw_spin_lock) from [<bf02116c>] (can_rx_register+0x94/0x15c [can])
| [<bf02116c>] (can_rx_register [can]) from [<bf02a868>] (raw_enable_filters+0x60/0xc0 [can_raw])
| [<bf02a868>] (raw_enable_filters [can_raw]) from [<bf02ac14>] (raw_enable_allfilters+0x2c/0xa0 [can_raw])
| [<bf02ac14>] (raw_enable_allfilters [can_raw]) from [<bf02ad38>] (raw_bind+0xb0/0x250 [can_raw])
| [<bf02ad38>] (raw_bind [can_raw]) from [<c03b5fb8>] (SyS_bind+0x70/0xac)
| [<c03b5fb8>] (SyS_bind) from [<c000f8c0>] (ret_fast_syscall+0x0/0x1c)

Cc: Mario Kicherer <dev@kicherer.org>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: complete initial namespace support

The statistics and its proc output was not implemented as per-net in the
initial network namespace support by Mario Kicherer (8e8cda6d737d).
This patch adds the missing per-net statistics for the CAN subsystem.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: remove obsolete pernet_operations definitions

The namespace support for the CAN subsystem does not need any additional
memory. So when ".size = 0" there's no extra memory allocated by the system.
And therefore ".id" is obsolete too.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: fix memory leak in initial namespace support

The can_rx_alldev_list is a per-net data structure now and allocated in
can_pernet_init(). Make sure the memory is free'd in can_pernet_exit() too.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: initial support for network namespaces

This patch adds initial support for network namespaces. The changes only
enable support in the CAN raw, proc and af_can code. GW and BCM still
have their checks that ensure that they are used only from the main
namespace.

The patch boils down to moving the global structures, i.e. the global
filter list and their /proc stats, into a per-namespace structure and passing
around the corresponding "struct net" in a lot of different places.

Changes since v1:
- rebased on current HEAD (2bfe01e)
- fixed overlong line

Signed-off-by: Mario Kicherer <dev@kicherer.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: Fix kernel panic at security_sock_rcv_skb

Zhang Yanmin reported crashes [1] and provided a patch adding a
synchronize_rcu() call in can_rx_unregister()

The main problem seems that the sockets themselves are not RCU
protected.

If CAN uses RCU for delivery, then sockets should be freed only after
one RCU grace period.

Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's
ease stable backports with the following fix instead.

[1]
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81495e25>] selinux_socket_sock_rcv_skb+0x65/0x2a0

Call Trace:
<IRQ>
[<ffffffff81485d8c>] security_sock_rcv_skb+0x4c/0x60
[<ffffffff81d55771>] sk_filter+0x41/0x210
[<ffffffff81d12913>] sock_queue_rcv_skb+0x53/0x3a0
[<ffffffff81f0a2b3>] raw_rcv+0x2a3/0x3c0
[<ffffffff81f06eab>] can_rcv_filter+0x12b/0x370
[<ffffffff81f07af9>] can_receive+0xd9/0x120
[<ffffffff81f07beb>] can_rcv+0xab/0x100
[<ffffffff81d362ac>] __netif_receive_skb_core+0xd8c/0x11f0
[<ffffffff81d36734>] __netif_receive_skb+0x24/0xb0
[<ffffffff81d37f67>] process_backlog+0x127/0x280
[<ffffffff81d36f7b>] net_rx_action+0x33b/0x4f0
[<ffffffff810c88d4>] __do_softirq+0x184/0x440
[<ffffffff81f9e86c>] do_softirq_own_stack+0x1c/0x30
<EOI>
[<ffffffff810c76fb>] do_softirq.part.18+0x3b/0x40
[<ffffffff810c8bed>] do_softirq+0x1d/0x20
[<ffffffff81d30085>] netif_rx_ni+0xe5/0x110
[<ffffffff8199cc87>] slcan_receive_buf+0x507/0x520
[<ffffffff8167ef7c>] flush_to_ldisc+0x21c/0x230
[<ffffffff810e3baf>] process_one_work+0x24f/0x670
[<ffffffff810e44ed>] worker_thread+0x9d/0x6f0
[<ffffffff810e4450>] ? rescuer_thread+0x480/0x480
[<ffffffff810ebafc>] kthread+0x12c/0x150
[<ffffffff81f9ccef>] ret_from_fork+0x3f/0x70

Reported-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: only call can_stat_update with procfs

The change to leave out procfs support in CAN when CONFIG_PROC_FS
is not set was incomplete and leads to a build error:

net/built-in.o: In function `can_init':
:(.init.text+0x9858): undefined reference to `can_stat_update'
ERROR: "can_stat_update" [net/can/can.ko] undefined!

This tries a better approach, encapsulating all of the calls
within IS_ENABLED(), so we also leave out the timer function
from the object file.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: a20fadf85312 ("can: build proc support only if CONFIG_PROC_FS is activated")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: replace timestamp as unique skb attribute

Commit 514ac99c64b "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 36c01245eb8 "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: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: fix loss of CAN frames in raw_rcv

As reported by Manfred Schlaegl here

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

commit 514ac99c64b "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: Manfred Schlaegl <manfred.schlaegl@gmx.at>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: Pass kern from net_proto_family.create to sk_alloc

In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: add missing initialisations in CAN related skbuffs

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: Austin Schuh <austin@peloton-tech.com>
Reported-by: Daniel Steer <daniel.steer@mclaren.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: fix spelling errors

Fix various spelling errors in the comments of the CAN modules.

Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: eliminate banner[] variable and switch to pr_info()

Several CAN modules use a design pattern with a banner[] variable at the
top which defines a string that is used once during init to print the
banner. The string is also embedded with KERN_INFO which makes it
printk() specific.

Improve the code by eliminating the banner[] variable and moving the
string to where it is printed. Then switch from printk(KERN_INFO to
pr_info() for the lines that were changed.

Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: add hash based access to single EFF frame filters

In contrast to the direct access to the single SFF frame filters (which are
indexed by the SFF CAN ID itself) the single EFF frame filters are arranged
in a single linked hlist. To reduce the hlist traversal in the case of many
filter subscriptions a hash based access is introduced for single EFF filters.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: add destructor for self generated skbs

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
376c7311bdb6 (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: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-by: Andre Naujoks <nautsch2@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Fix common typo in "identify"

Correct common misspelling of "identify" as "indentify" throughout
the kernel

Signed-off-by: Maxime Jayat <maxime@artisandeveloppeur.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

net: pass info struct via netdevice notifier

So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
shortened dev_getter
shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>

can: dump stack on protocol bugs

The rework of the kernel hlist implementation "hlist: drop the node parameter
from iterators" (b67bfe0d42cac56c512dd5da4b1b347a23f4b70a) created some
fallout in the form of non matching comments and obsolete code.

Additionally to the cleanup this patch adds a WARN() statement to catch the
caller of the wrong filter removal request.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: can: af_can.c: Fix checkpatch warnings

Replace printk(KERN_ERR with pr_err
Add space before {
Removed OOM messages

Signed-off-by: Valentin Ilie <valentin.ilie@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sections: fix section conflicts in net/can

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

canfd: add support for CAN FD in PF_CAN core

- handle ETH_P_CAN and ETH_P_CANFD skbuffs
- update sanity checks for CAN and CAN FD
- make sure the CAN frame can pass the selected CAN netdevice on send
- bump core version and abi version to indicate the new CAN FD support

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

canfd: add new data structures and constants

- add new struct canfd_frame
- check identical element offsets in struct can_frame and struct canfd_frame
- new ETH_P_CANFD definition to tag CAN FD skbs correctly
- add CAN_MTU and CANFD_MTU definitions for easy frame and mode detection
- add CAN[FD]_MAX_[DLC|DLEN] helper constants to remove hard coded values
- update existing struct can_frame with helper constants and comments

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: update documentation wording error frames -> error messages

As Heinz-Juergen Oertel pointed out 'CAN error frames' are a already defined
term for the CAN protocol violation indication on the wire.

To avoid confusion with the error messages created by CAN drivers available
via CAN RAW sockets update the documentation and change the naming from
'error frames' to 'error messages' or 'error message frames'.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: remove references to berlios mailinglist

The BerliOS project, which currently hosts our mailinglist, will
close with the end of the year. Now take the chance and remove all
occurrences of the mailinglist address from the source files.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/can/af_can.c: Change del_timer to del_timer_sync

This is important for SMP platform to check if timer function is
executing on other CPU with deleting the timer.

Signed-off-by: Rajan Aggarwal <Rajan Aggarwal rajan.aggarwal85@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/can: use printk_ratelimited() instead of printk_ratelimit()

Since printk_ratelimit() shouldn't be used anymore (see comment in
include/linux/printk.h), replace it with printk_ratelimited().

Signed-off-by: Manuel Zerpies <manuel.f.zerpies@ww.stud.uni-erlangen.de>
Signed-off-by: David S. Miller <davem@conan.davemloft.net>

can: rename can_try_module_get to can_get_proto

can: rename can_try_module_get to can_get_proto

can_try_module_get does return a struct can_proto.
The name explains what is done in so much detail that a caller
may not notice that a struct can_proto is locked/unlocked.

Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: make struct can_proto const

commit 53914b67993c724cec585863755c9ebc8446e83b had the
same message. That commit did put everything in place but
did not make can_proto const itself.

Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: convert protocol handling to RCU

This patch removes spin_locks at CAN socket creation time by using RCU.

Inspired by the discussion with Kurt van Dijck and Eric Dumazet the RCU code
was partly derived from af_phonet.c

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: make struct proto const

can_ioctl is the only reason for struct proto to be non-const.
script/check-patch.pl suggests struct proto be const.

Setting the reference to the common can_ioctl() in all CAN protocols directly
removes the need to make the struct proto writable in af_can.c

Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: deny filterlist access on non-CAN interfaces

In commit 20dd3850bcf860561496827b711fa10fecf6e787 "can: Speed up CAN frame
receiption by using ml_priv" the formerly used hlist of receiver lists for
each CAN netdevice has been replaced.

The hlist content ensured only CAN netdevices to be accessed by the
can_rx_(un)register() functions which accidently dropped away together with
the hlist receiver implementation.

This patch re-introduces the check for CAN netdevices in can_rx_(un)register().

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: Speed up CAN frame receiption by using ml_priv

this patch removes the hlist that contains the CAN receiver filter lists.
It uses the 'midlayer private' pointer ml_priv and links the filters directly
to the CAN netdevice, which allows to omit the walk through the complete CAN
devices hlist for each received CAN frame.

This patch is tested and does not remove any locking.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Move && and || to end of previous line

Not including net/atm/

Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use net_eq to compare nets

Generated with the following semantic patch

@@
struct net *n1;
struct net *n2;
@@
- n1 == n2
+ net_eq(n1, n2)

@@
struct net *n1;
struct net *n2;
@@
- n1 != n2
+ !net_eq(n1, n2)

applied over {include,net,drivers/net}.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: pass kern to net_proto_family create function

The generic __sock_create function has a kern argument which allows the
security system to make decisions based on if a socket is being created by
the kernel or by userspace. This patch passes that flag to the
net_proto_family specific create function, so it can do the same thing.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: drop capability from protocol definitions

struct can_proto had a capability field which wasn't ever used. It is
dropped entirely.

struct inet_protosw had a capability field which can be more clearly
expressed in the code by just checking if sock->type = SOCK_RAW.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mark net_proto_ops as const

All usages of structure net_proto_ops should be declared const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: fix NOHZ local_softirq_pending 08 warning

When using nanosleep() in an userspace application we get a ratelimit warning

NOHZ: local_softirq_pending 08

for 10 times.

The echo of CAN frames is done from process context and softirq context only.
Therefore the usage of netif_rx() was wrong (for years).

This patch replaces netif_rx() with netif_rx_ni() which has to be used from
process/softirq context. It also adds a missing comment that can_send() must
no be used from hardirq context.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Urs Thuermann <urs@isnogud.escape.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: use correct NET_RX_ return values

Dropped skb's should be documented by an appropriate return value.
Use the correct NET_RX_DROP and NET_RX_SUCCESS values for that reason.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: Use WARN_ONCE() instead of BUG_ON() for sanity check in receive path

To ensure a proper handling of CAN frames transported in skbuffs some checks
need to be performed at receive time.

As stated by Michael Olbrich and Luotao Fu BUG_ON() might be to restrictive.
This is right as we can just drop the non conform skbuff and the Kernel can
continue working.

This patch replaces the BUG_ON() with a WARN_ONCE() so that the system remains
healthy but we made the problem visible (once).

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Urs Thuermann <urs@isnogud.escape.de>
CC: Michael Olbrich <m.olbrich@pengutronix.de>
CC: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: af_can.c use rcu_barrier() on module unload.

This module uses rcu_call() thus it should use rcu_barrier()
on module unload.

Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Acked-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: Network Drop Monitor: Make use of consume_skb() in af_can.c

Since commit ead2ceb0ec9f85cff19c43b5cdb2f8a054484431 ("Network Drop
Monitor: Adding kfree_skb_clean for non-drops and modifying
end-of-line points for skbs") so called end-of-line points for skb's
should use consume_skb() to free the socket buffer.

In opposite to consume_skb() the function kfree_skb() is intended to
be used for unexpected skb drops e.g. in error conditions that now can
trigger the network drop monitor if enabled.

This patch moves the skb end-of-line point in af_can.c to use
consume_skb().

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: remove some pointless conditionals before kfree_skb()

Remove some pointless conditionals before kfree_skb().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: replace uses of __constant_{endian}

Base versions handle constant folding now.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: omit unneeded skb_clone() calls

The AF_CAN core delivered always cloned sk_buffs to the AF_CAN
protocols, although this was _only_ needed by the can-raw protocol.
With this (additionally documented) change, the AF_CAN core calls the
callback functions of the registered AF_CAN protocols with the original
(uncloned) sk_buff pointer and let's the can-raw protocol do the
skb_clone() itself which omits all unneeded skb_clone() calls for other
AF_CAN protocols.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: omit received RTR frames for single ID filter lists

Since commit d253eee20195b25e298bf162a6e72f14bf4803e5 the single CAN
identifier filter lists handle only non-RTR CAN frames.

So we need to omit the check of these filter lists when receiving RTR
CAN frames.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: Fix CAN_(EFF|RTR)_FLAG handling in can_filter

Due to a wrong safety check in af_can.c it was not possible to filter
for SFF frames with a specific CAN identifier without getting the
same selected CAN identifier from a received EFF frame also.

This fix has a minimum (but user visible) impact on the CAN filter
API and therefore the CAN version is set to a new date.

Indeed the 'old' API is still working as-is. But when now setting
CAN_(EFF|RTR)_FLAG in can_filter.can_mask you might get less traffic
than before - but still the stuff that you expected to get for your
defined filter ...

Thanks to Kurt Van Dijck for pointing at this issue and for the review.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Remove CONFIG_KMOD from net/ (towards removing CONFIG_KMOD entirely)

Some code here depends on CONFIG_KMOD to not try to load
protocol modules or similar, replace by CONFIG_MODULES
where more than just request_module depends on CONFIG_KMOD
and and also use try_then_request_module in ebtables.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: Use net_eq() to compare net-namespaces for optimization.

Without CONFIG_NET_NS, namespace is always &init_net.
Compiler will be able to omit namespace comparisons with this patch.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: add sanity checks

Even though the CAN netlayer only deals with CAN netdevices, the
netlayer interface to the userspace and to the device layer should
perform some sanity checks.

This patch adds several sanity checks that mainly prevent userspace apps
to send broken content into the system that may be misinterpreted by
some other userspace application.

Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Acked-by: Andre Naujoks <nautsch@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: Fix can_send() handling on dev_queue_xmit() failures

The tx packet counting and the local loopback of CAN frames should
only happen in the case that the CAN frame has been enqueued to the
netdevice tx queue successfully.

Thanks to Andre Naujoks <nautsch@gmail.com> for reporting this issue.

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Urs Thuermann <urs@isnogud.escape.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS.

Introduce per-net_device inlines: dev_net(), dev_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

[CAN]: Move proto_{,un}register() out of spin-locked region

The implementation of proto_register() has changed so that it can now
sleep. The call to proto_register() must be moved out of the
spin-locked region.

Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

[CAN]: Clean up module auto loading

Remove local char array to construct module name.
Don't call request_module() when CONFIG_KMOD is not set.

Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

[CAN]: Add PF_CAN core module

This patch adds the CAN core functionality but no protocols or drivers.
No protocol implementations are included here. They come as separate
patches. Protocol numbers are already in include/linux/can.h.

Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>