1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /* af_can.c - Protocol family CAN core module
3 * (used by different CAN protocol modules)
5 * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of Volkswagen nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * Alternatively, provided that this notice is retained in full, this
21 * software may be distributed under the terms of the GNU General
22 * Public License ("GPL") version 2, in which case the provisions of the
23 * GPL apply INSTEAD OF those given above.
25 * The provided data structures and external interfaces from this code
26 * are not restricted to be used by modules with a GPL compatible license.
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
43 #include <linux/module.h>
44 #include <linux/stddef.h>
45 #include <linux/init.h>
46 #include <linux/kmod.h>
47 #include <linux/slab.h>
48 #include <linux/list.h>
49 #include <linux/spinlock.h>
50 #include <linux/rcupdate.h>
51 #include <linux/uaccess.h>
52 #include <linux/net.h>
53 #include <linux/netdevice.h>
54 #include <linux/socket.h>
55 #include <linux/if_ether.h>
56 #include <linux/if_arp.h>
57 #include <linux/skbuff.h>
58 #include <linux/can.h>
59 #include <linux/can/core.h>
60 #include <linux/can/skb.h>
61 #include <linux/can/can-ml.h>
62 #include <linux/ratelimit.h>
63 #include <net/net_namespace.h>
68 MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
69 MODULE_LICENSE("Dual BSD/GPL");
70 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
71 "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
73 MODULE_ALIAS_NETPROTO(PF_CAN
);
75 static int stats_timer __read_mostly
= 1;
76 module_param(stats_timer
, int, 0444);
77 MODULE_PARM_DESC(stats_timer
, "enable timer for statistics (default:on)");
79 static struct kmem_cache
*rcv_cache __read_mostly
;
81 /* table of registered CAN protocols */
82 static const struct can_proto __rcu
*proto_tab
[CAN_NPROTO
] __read_mostly
;
83 static DEFINE_MUTEX(proto_tab_lock
);
85 static atomic_t skbcounter
= ATOMIC_INIT(0);
87 /* af_can socket functions */
89 static void can_sock_destruct(struct sock
*sk
)
91 skb_queue_purge(&sk
->sk_receive_queue
);
92 skb_queue_purge(&sk
->sk_error_queue
);
95 static const struct can_proto
*can_get_proto(int protocol
)
97 const struct can_proto
*cp
;
100 cp
= rcu_dereference(proto_tab
[protocol
]);
101 if (cp
&& !try_module_get(cp
->prot
->owner
))
108 static inline void can_put_proto(const struct can_proto
*cp
)
110 module_put(cp
->prot
->owner
);
113 static int can_create(struct net
*net
, struct socket
*sock
, int protocol
,
117 const struct can_proto
*cp
;
120 sock
->state
= SS_UNCONNECTED
;
122 if (protocol
< 0 || protocol
>= CAN_NPROTO
)
125 cp
= can_get_proto(protocol
);
127 #ifdef CONFIG_MODULES
129 /* try to load protocol module if kernel is modular */
131 err
= request_module("can-proto-%d", protocol
);
133 /* In case of error we only print a message but don't
134 * return the error code immediately. Below we will
135 * return -EPROTONOSUPPORT
138 pr_err_ratelimited("can: request_module (can-proto-%d) failed.\n",
141 cp
= can_get_proto(protocol
);
145 /* check for available protocol and correct usage */
148 return -EPROTONOSUPPORT
;
150 if (cp
->type
!= sock
->type
) {
157 sk
= sk_alloc(net
, PF_CAN
, GFP_KERNEL
, cp
->prot
, kern
);
163 sock_init_data(sock
, sk
);
164 sk
->sk_destruct
= can_sock_destruct
;
166 if (sk
->sk_prot
->init
)
167 err
= sk
->sk_prot
->init(sk
);
170 /* release sk on errors */
183 * can_send - transmit a CAN frame (optional with local loopback)
184 * @skb: pointer to socket buffer with CAN frame in data section
185 * @loop: loopback for listeners on local CAN sockets (recommended default!)
187 * Due to the loopback this routine must not be called from hardirq context.
191 * -ENETDOWN when the selected interface is down
192 * -ENOBUFS on full driver queue (see net_xmit_errno())
193 * -ENOMEM when local loopback failed at calling skb_clone()
194 * -EPERM when trying to send on a non-CAN interface
195 * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
196 * -EINVAL when the skb->data does not contain a valid CAN frame
198 int can_send(struct sk_buff
*skb
, int loop
)
200 struct sk_buff
*newskb
= NULL
;
201 struct canfd_frame
*cfd
= (struct canfd_frame
*)skb
->data
;
202 struct can_pkg_stats
*pkg_stats
= dev_net(skb
->dev
)->can
.pkg_stats
;
205 if (skb
->len
== CAN_MTU
) {
206 skb
->protocol
= htons(ETH_P_CAN
);
207 if (unlikely(cfd
->len
> CAN_MAX_DLEN
))
209 } else if (skb
->len
== CANFD_MTU
) {
210 skb
->protocol
= htons(ETH_P_CANFD
);
211 if (unlikely(cfd
->len
> CANFD_MAX_DLEN
))
217 /* Make sure the CAN frame can pass the selected CAN netdevice.
218 * As structs can_frame and canfd_frame are similar, we can provide
219 * CAN FD frames to legacy CAN drivers as long as the length is <= 8
221 if (unlikely(skb
->len
> skb
->dev
->mtu
&& cfd
->len
> CAN_MAX_DLEN
)) {
226 if (unlikely(skb
->dev
->type
!= ARPHRD_CAN
)) {
231 if (unlikely(!(skb
->dev
->flags
& IFF_UP
))) {
236 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
238 skb_reset_mac_header(skb
);
239 skb_reset_network_header(skb
);
240 skb_reset_transport_header(skb
);
243 /* local loopback of sent CAN frames */
245 /* indication for the CAN driver: do loopback */
246 skb
->pkt_type
= PACKET_LOOPBACK
;
248 /* The reference to the originating sock may be required
249 * by the receiving socket to check whether the frame is
250 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
251 * Therefore we have to ensure that skb->sk remains the
252 * reference to the originating sock by restoring skb->sk
253 * after each skb_clone() or skb_orphan() usage.
256 if (!(skb
->dev
->flags
& IFF_ECHO
)) {
257 /* If the interface is not capable to do loopback
258 * itself, we do it here.
260 newskb
= skb_clone(skb
, GFP_ATOMIC
);
266 can_skb_set_owner(newskb
, skb
->sk
);
267 newskb
->ip_summed
= CHECKSUM_UNNECESSARY
;
268 newskb
->pkt_type
= PACKET_BROADCAST
;
271 /* indication for the CAN driver: no loopback required */
272 skb
->pkt_type
= PACKET_HOST
;
275 /* send to netdevice */
276 err
= dev_queue_xmit(skb
);
278 err
= net_xmit_errno(err
);
288 /* update statistics */
289 pkg_stats
->tx_frames
++;
290 pkg_stats
->tx_frames_delta
++;
298 EXPORT_SYMBOL(can_send
);
302 static struct can_dev_rcv_lists
*can_dev_rcv_lists_find(struct net
*net
,
303 struct net_device
*dev
)
306 struct can_ml_priv
*ml_priv
= dev
->ml_priv
;
307 return &ml_priv
->dev_rcv_lists
;
309 return net
->can
.rx_alldev_list
;
314 * effhash - hash function for 29 bit CAN identifier reduction
315 * @can_id: 29 bit CAN identifier
318 * To reduce the linear traversal in one linked list of _single_ EFF CAN
319 * frame subscriptions the 29 bit identifier is mapped to 10 bits.
320 * (see CAN_EFF_RCV_HASH_BITS definition)
323 * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
325 static unsigned int effhash(canid_t can_id
)
330 hash
^= can_id
>> CAN_EFF_RCV_HASH_BITS
;
331 hash
^= can_id
>> (2 * CAN_EFF_RCV_HASH_BITS
);
333 return hash
& ((1 << CAN_EFF_RCV_HASH_BITS
) - 1);
337 * can_rcv_list_find - determine optimal filterlist inside device filter struct
338 * @can_id: pointer to CAN identifier of a given can_filter
339 * @mask: pointer to CAN mask of a given can_filter
340 * @d: pointer to the device filter struct
343 * Returns the optimal filterlist to reduce the filter handling in the
344 * receive path. This function is called by service functions that need
345 * to register or unregister a can_filter in the filter lists.
347 * A filter matches in general, when
349 * <received_can_id> & mask == can_id & mask
351 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
352 * relevant bits for the filter.
354 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
355 * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
356 * frames there is a special filterlist and a special rx path filter handling.
359 * Pointer to optimal filterlist for the given can_id/mask pair.
360 * Constistency checked mask.
361 * Reduced can_id to have a preprocessed filter compare value.
363 static struct hlist_head
*can_rcv_list_find(canid_t
*can_id
, canid_t
*mask
,
364 struct can_dev_rcv_lists
*dev_rcv_lists
)
366 canid_t inv
= *can_id
& CAN_INV_FILTER
; /* save flag before masking */
368 /* filter for error message frames in extra filterlist */
369 if (*mask
& CAN_ERR_FLAG
) {
370 /* clear CAN_ERR_FLAG in filter entry */
371 *mask
&= CAN_ERR_MASK
;
372 return &dev_rcv_lists
->rx
[RX_ERR
];
375 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
377 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
379 /* ensure valid values in can_mask for 'SFF only' frame filtering */
380 if ((*mask
& CAN_EFF_FLAG
) && !(*can_id
& CAN_EFF_FLAG
))
381 *mask
&= (CAN_SFF_MASK
| CAN_EFF_RTR_FLAGS
);
383 /* reduce condition testing at receive time */
386 /* inverse can_id/can_mask filter */
388 return &dev_rcv_lists
->rx
[RX_INV
];
390 /* mask == 0 => no condition testing at receive time */
392 return &dev_rcv_lists
->rx
[RX_ALL
];
394 /* extra filterlists for the subscription of a single non-RTR can_id */
395 if (((*mask
& CAN_EFF_RTR_FLAGS
) == CAN_EFF_RTR_FLAGS
) &&
396 !(*can_id
& CAN_RTR_FLAG
)) {
397 if (*can_id
& CAN_EFF_FLAG
) {
398 if (*mask
== (CAN_EFF_MASK
| CAN_EFF_RTR_FLAGS
))
399 return &dev_rcv_lists
->rx_eff
[effhash(*can_id
)];
401 if (*mask
== (CAN_SFF_MASK
| CAN_EFF_RTR_FLAGS
))
402 return &dev_rcv_lists
->rx_sff
[*can_id
];
406 /* default: filter via can_id/can_mask */
407 return &dev_rcv_lists
->rx
[RX_FIL
];
411 * can_rx_register - subscribe CAN frames from a specific interface
412 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
413 * @can_id: CAN identifier (see description)
414 * @mask: CAN mask (see description)
415 * @func: callback function on filter match
416 * @data: returned parameter for callback function
417 * @ident: string for calling module identification
418 * @sk: socket pointer (might be NULL)
421 * Invokes the callback function with the received sk_buff and the given
422 * parameter 'data' on a matching receive filter. A filter matches, when
424 * <received_can_id> & mask == can_id & mask
426 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
427 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
429 * The provided pointer to the sk_buff is guaranteed to be valid as long as
430 * the callback function is running. The callback function must *not* free
431 * the given sk_buff while processing it's task. When the given sk_buff is
432 * needed after the end of the callback function it must be cloned inside
433 * the callback function with skb_clone().
437 * -ENOMEM on missing cache mem to create subscription entry
438 * -ENODEV unknown device
440 int can_rx_register(struct net
*net
, struct net_device
*dev
, canid_t can_id
,
441 canid_t mask
, void (*func
)(struct sk_buff
*, void *),
442 void *data
, char *ident
, struct sock
*sk
)
444 struct receiver
*rcv
;
445 struct hlist_head
*rcv_list
;
446 struct can_dev_rcv_lists
*dev_rcv_lists
;
447 struct can_rcv_lists_stats
*rcv_lists_stats
= net
->can
.rcv_lists_stats
;
450 /* insert new receiver (dev,canid,mask) -> (func,data) */
452 if (dev
&& dev
->type
!= ARPHRD_CAN
)
455 if (dev
&& !net_eq(net
, dev_net(dev
)))
458 rcv
= kmem_cache_alloc(rcv_cache
, GFP_KERNEL
);
462 spin_lock(&net
->can
.rcvlists_lock
);
464 dev_rcv_lists
= can_dev_rcv_lists_find(net
, dev
);
466 rcv_list
= can_rcv_list_find(&can_id
, &mask
, dev_rcv_lists
);
468 rcv
->can_id
= can_id
;
476 hlist_add_head_rcu(&rcv
->list
, rcv_list
);
477 dev_rcv_lists
->entries
++;
479 rcv_lists_stats
->rcv_entries
++;
480 rcv_lists_stats
->rcv_entries_max
= max(rcv_lists_stats
->rcv_entries_max
,
481 rcv_lists_stats
->rcv_entries
);
483 kmem_cache_free(rcv_cache
, rcv
);
487 spin_unlock(&net
->can
.rcvlists_lock
);
491 EXPORT_SYMBOL(can_rx_register
);
493 /* can_rx_delete_receiver - rcu callback for single receiver entry removal */
494 static void can_rx_delete_receiver(struct rcu_head
*rp
)
496 struct receiver
*rcv
= container_of(rp
, struct receiver
, rcu
);
497 struct sock
*sk
= rcv
->sk
;
499 kmem_cache_free(rcv_cache
, rcv
);
505 * can_rx_unregister - unsubscribe CAN frames from a specific interface
506 * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
507 * @can_id: CAN identifier
509 * @func: callback function on filter match
510 * @data: returned parameter for callback function
513 * Removes subscription entry depending on given (subscription) values.
515 void can_rx_unregister(struct net
*net
, struct net_device
*dev
, canid_t can_id
,
516 canid_t mask
, void (*func
)(struct sk_buff
*, void *),
519 struct receiver
*rcv
= NULL
;
520 struct hlist_head
*rcv_list
;
521 struct can_rcv_lists_stats
*rcv_lists_stats
= net
->can
.rcv_lists_stats
;
522 struct can_dev_rcv_lists
*dev_rcv_lists
;
524 if (dev
&& dev
->type
!= ARPHRD_CAN
)
527 if (dev
&& !net_eq(net
, dev_net(dev
)))
530 spin_lock(&net
->can
.rcvlists_lock
);
532 dev_rcv_lists
= can_dev_rcv_lists_find(net
, dev
);
533 if (!dev_rcv_lists
) {
534 pr_err("BUG: receive list not found for dev %s, id %03X, mask %03X\n",
535 DNAME(dev
), can_id
, mask
);
539 rcv_list
= can_rcv_list_find(&can_id
, &mask
, dev_rcv_lists
);
541 /* Search the receiver list for the item to delete. This should
542 * exist, since no receiver may be unregistered that hasn't
543 * been registered before.
545 hlist_for_each_entry_rcu(rcv
, rcv_list
, list
) {
546 if (rcv
->can_id
== can_id
&& rcv
->mask
== mask
&&
547 rcv
->func
== func
&& rcv
->data
== data
)
551 /* Check for bugs in CAN protocol implementations using af_can.c:
552 * 'rcv' will be NULL if no matching list item was found for removal.
555 WARN(1, "BUG: receive list entry not found for dev %s, id %03X, mask %03X\n",
556 DNAME(dev
), can_id
, mask
);
560 hlist_del_rcu(&rcv
->list
);
561 dev_rcv_lists
->entries
--;
563 if (rcv_lists_stats
->rcv_entries
> 0)
564 rcv_lists_stats
->rcv_entries
--;
567 spin_unlock(&net
->can
.rcvlists_lock
);
569 /* schedule the receiver item for deletion */
573 call_rcu(&rcv
->rcu
, can_rx_delete_receiver
);
576 EXPORT_SYMBOL(can_rx_unregister
);
578 static inline void deliver(struct sk_buff
*skb
, struct receiver
*rcv
)
580 rcv
->func(skb
, rcv
->data
);
584 static int can_rcv_filter(struct can_dev_rcv_lists
*dev_rcv_lists
, struct sk_buff
*skb
)
586 struct receiver
*rcv
;
588 struct can_frame
*cf
= (struct can_frame
*)skb
->data
;
589 canid_t can_id
= cf
->can_id
;
591 if (dev_rcv_lists
->entries
== 0)
594 if (can_id
& CAN_ERR_FLAG
) {
595 /* check for error message frame entries only */
596 hlist_for_each_entry_rcu(rcv
, &dev_rcv_lists
->rx
[RX_ERR
], list
) {
597 if (can_id
& rcv
->mask
) {
605 /* check for unfiltered entries */
606 hlist_for_each_entry_rcu(rcv
, &dev_rcv_lists
->rx
[RX_ALL
], list
) {
611 /* check for can_id/mask entries */
612 hlist_for_each_entry_rcu(rcv
, &dev_rcv_lists
->rx
[RX_FIL
], list
) {
613 if ((can_id
& rcv
->mask
) == rcv
->can_id
) {
619 /* check for inverted can_id/mask entries */
620 hlist_for_each_entry_rcu(rcv
, &dev_rcv_lists
->rx
[RX_INV
], list
) {
621 if ((can_id
& rcv
->mask
) != rcv
->can_id
) {
627 /* check filterlists for single non-RTR can_ids */
628 if (can_id
& CAN_RTR_FLAG
)
631 if (can_id
& CAN_EFF_FLAG
) {
632 hlist_for_each_entry_rcu(rcv
, &dev_rcv_lists
->rx_eff
[effhash(can_id
)], list
) {
633 if (rcv
->can_id
== can_id
) {
639 can_id
&= CAN_SFF_MASK
;
640 hlist_for_each_entry_rcu(rcv
, &dev_rcv_lists
->rx_sff
[can_id
], list
) {
649 static void can_receive(struct sk_buff
*skb
, struct net_device
*dev
)
651 struct can_dev_rcv_lists
*dev_rcv_lists
;
652 struct net
*net
= dev_net(dev
);
653 struct can_pkg_stats
*pkg_stats
= net
->can
.pkg_stats
;
656 /* update statistics */
657 pkg_stats
->rx_frames
++;
658 pkg_stats
->rx_frames_delta
++;
660 /* create non-zero unique skb identifier together with *skb */
661 while (!(can_skb_prv(skb
)->skbcnt
))
662 can_skb_prv(skb
)->skbcnt
= atomic_inc_return(&skbcounter
);
666 /* deliver the packet to sockets listening on all devices */
667 matches
= can_rcv_filter(net
->can
.rx_alldev_list
, skb
);
669 /* find receive list for this device */
670 dev_rcv_lists
= can_dev_rcv_lists_find(net
, dev
);
672 matches
+= can_rcv_filter(dev_rcv_lists
, skb
);
676 /* consume the skbuff allocated by the netdevice driver */
680 pkg_stats
->matches
++;
681 pkg_stats
->matches_delta
++;
685 static int can_rcv(struct sk_buff
*skb
, struct net_device
*dev
,
686 struct packet_type
*pt
, struct net_device
*orig_dev
)
688 struct canfd_frame
*cfd
= (struct canfd_frame
*)skb
->data
;
690 if (unlikely(dev
->type
!= ARPHRD_CAN
|| skb
->len
!= CAN_MTU
||
691 cfd
->len
> CAN_MAX_DLEN
)) {
692 pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, datalen %d\n",
693 dev
->type
, skb
->len
, cfd
->len
);
698 can_receive(skb
, dev
);
699 return NET_RX_SUCCESS
;
702 static int canfd_rcv(struct sk_buff
*skb
, struct net_device
*dev
,
703 struct packet_type
*pt
, struct net_device
*orig_dev
)
705 struct canfd_frame
*cfd
= (struct canfd_frame
*)skb
->data
;
707 if (unlikely(dev
->type
!= ARPHRD_CAN
|| skb
->len
!= CANFD_MTU
||
708 cfd
->len
> CANFD_MAX_DLEN
)) {
709 pr_warn_once("PF_CAN: dropped non conform CAN FD skbuf: dev type %d, len %d, datalen %d\n",
710 dev
->type
, skb
->len
, cfd
->len
);
715 can_receive(skb
, dev
);
716 return NET_RX_SUCCESS
;
719 /* af_can protocol functions */
722 * can_proto_register - register CAN transport protocol
723 * @cp: pointer to CAN protocol structure
727 * -EINVAL invalid (out of range) protocol number
728 * -EBUSY protocol already in use
729 * -ENOBUF if proto_register() fails
731 int can_proto_register(const struct can_proto
*cp
)
733 int proto
= cp
->protocol
;
736 if (proto
< 0 || proto
>= CAN_NPROTO
) {
737 pr_err("can: protocol number %d out of range\n", proto
);
741 err
= proto_register(cp
->prot
, 0);
745 mutex_lock(&proto_tab_lock
);
747 if (rcu_access_pointer(proto_tab
[proto
])) {
748 pr_err("can: protocol %d already registered\n", proto
);
751 RCU_INIT_POINTER(proto_tab
[proto
], cp
);
754 mutex_unlock(&proto_tab_lock
);
757 proto_unregister(cp
->prot
);
761 EXPORT_SYMBOL(can_proto_register
);
764 * can_proto_unregister - unregister CAN transport protocol
765 * @cp: pointer to CAN protocol structure
767 void can_proto_unregister(const struct can_proto
*cp
)
769 int proto
= cp
->protocol
;
771 mutex_lock(&proto_tab_lock
);
772 BUG_ON(rcu_access_pointer(proto_tab
[proto
]) != cp
);
773 RCU_INIT_POINTER(proto_tab
[proto
], NULL
);
774 mutex_unlock(&proto_tab_lock
);
778 proto_unregister(cp
->prot
);
780 EXPORT_SYMBOL(can_proto_unregister
);
782 /* af_can notifier to create/remove CAN netdevice specific structs */
783 static int can_notifier(struct notifier_block
*nb
, unsigned long msg
,
786 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
788 if (dev
->type
!= ARPHRD_CAN
)
792 case NETDEV_REGISTER
:
794 "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n");
801 static int can_pernet_init(struct net
*net
)
803 spin_lock_init(&net
->can
.rcvlists_lock
);
804 net
->can
.rx_alldev_list
=
805 kzalloc(sizeof(*net
->can
.rx_alldev_list
), GFP_KERNEL
);
806 if (!net
->can
.rx_alldev_list
)
808 net
->can
.pkg_stats
= kzalloc(sizeof(*net
->can
.pkg_stats
), GFP_KERNEL
);
809 if (!net
->can
.pkg_stats
)
810 goto out_free_rx_alldev_list
;
811 net
->can
.rcv_lists_stats
= kzalloc(sizeof(*net
->can
.rcv_lists_stats
), GFP_KERNEL
);
812 if (!net
->can
.rcv_lists_stats
)
813 goto out_free_pkg_stats
;
815 if (IS_ENABLED(CONFIG_PROC_FS
)) {
816 /* the statistics are updated every second (timer triggered) */
818 timer_setup(&net
->can
.stattimer
, can_stat_update
,
820 mod_timer(&net
->can
.stattimer
,
821 round_jiffies(jiffies
+ HZ
));
823 net
->can
.pkg_stats
->jiffies_init
= jiffies
;
830 kfree(net
->can
.pkg_stats
);
831 out_free_rx_alldev_list
:
832 kfree(net
->can
.rx_alldev_list
);
837 static void can_pernet_exit(struct net
*net
)
839 if (IS_ENABLED(CONFIG_PROC_FS
)) {
840 can_remove_proc(net
);
842 del_timer_sync(&net
->can
.stattimer
);
845 kfree(net
->can
.rx_alldev_list
);
846 kfree(net
->can
.pkg_stats
);
847 kfree(net
->can
.rcv_lists_stats
);
850 /* af_can module init/exit functions */
852 static struct packet_type can_packet __read_mostly
= {
853 .type
= cpu_to_be16(ETH_P_CAN
),
857 static struct packet_type canfd_packet __read_mostly
= {
858 .type
= cpu_to_be16(ETH_P_CANFD
),
862 static const struct net_proto_family can_family_ops
= {
864 .create
= can_create
,
865 .owner
= THIS_MODULE
,
868 /* notifier block for netdevice event */
869 static struct notifier_block can_netdev_notifier __read_mostly
= {
870 .notifier_call
= can_notifier
,
873 static struct pernet_operations can_pernet_ops __read_mostly
= {
874 .init
= can_pernet_init
,
875 .exit
= can_pernet_exit
,
878 static __init
int can_init(void)
882 /* check for correct padding to be able to use the structs similarly */
883 BUILD_BUG_ON(offsetof(struct can_frame
, can_dlc
) !=
884 offsetof(struct canfd_frame
, len
) ||
885 offsetof(struct can_frame
, data
) !=
886 offsetof(struct canfd_frame
, data
));
888 pr_info("can: controller area network core (" CAN_VERSION_STRING
")\n");
890 rcv_cache
= kmem_cache_create("can_receiver", sizeof(struct receiver
),
895 err
= register_pernet_subsys(&can_pernet_ops
);
899 /* protocol register */
900 err
= sock_register(&can_family_ops
);
903 err
= register_netdevice_notifier(&can_netdev_notifier
);
907 dev_add_pack(&can_packet
);
908 dev_add_pack(&canfd_packet
);
913 sock_unregister(PF_CAN
);
915 unregister_pernet_subsys(&can_pernet_ops
);
917 kmem_cache_destroy(rcv_cache
);
922 static __exit
void can_exit(void)
924 /* protocol unregister */
925 dev_remove_pack(&canfd_packet
);
926 dev_remove_pack(&can_packet
);
927 unregister_netdevice_notifier(&can_netdev_notifier
);
928 sock_unregister(PF_CAN
);
930 unregister_pernet_subsys(&can_pernet_ops
);
932 rcu_barrier(); /* Wait for completion of call_rcu()'s */
934 kmem_cache_destroy(rcv_cache
);
937 module_init(can_init
);
938 module_exit(can_exit
);