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: 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: add missing identifiers to struct receiver::func

This patch adds the missing identifiers to the struct receiver::func
declaration.

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: 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>

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: 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 definitions

can_rx_alldev_list is a per-net data structure now. Remove it's definition
here and can_rx_dev_list 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: build proc support only if CONFIG_PROC_FS is activated

When building can subsystem with CONFIG_PROC_FS=n I detected some unused
variables warning by using proc functions. In CAN the proc handling is
nicely placed in one object file. This patch adds simple add a
dependency on CONFIG_PROC_FS for CAN's proc.o file and corresponding
static inline no-op functions.

Signed-off-by: Alexander Aring <aar@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
[mkl: provide static inline noops instead of using #ifdefs]
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: proc: make array printing function indenpendent from sff frames

The can_rcvlist_sff_proc_show_one() function which prints the array of filters
for the single SFF CAN identifiers is prepared to be used by a second caller.
Therefore it is also renamed to properly describe its future functionality.

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

net: 8021q/bluetooth/bridge/can/ceph: Remove extern from function prototypes

There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler. Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

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

can: fix sparse warning in af_can.c

Put can_rx_alldev_list into the af_can header to fix the following
sparse warning: net/can/af_can.c:80:22: warning: symbol
'can_rx_alldev_list' was not declared. Should it be static?

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>

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>

[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>