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/ratelimit.h>
62 #include <net/net_namespace.h>
67 MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
68 MODULE_LICENSE("Dual BSD/GPL");
69 MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
70 "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
72 MODULE_ALIAS_NETPROTO(PF_CAN);
74 static int stats_timer __read_mostly = 1;
75 module_param(stats_timer, int, 0444);
76 MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
78 static struct kmem_cache *rcv_cache __read_mostly;
80 /* table of registered CAN protocols */
81 static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly;
82 static DEFINE_MUTEX(proto_tab_lock);
84 static atomic_t skbcounter = ATOMIC_INIT(0);
86 /* af_can socket functions */
88 static void can_sock_destruct(struct sock *sk)
90 skb_queue_purge(&sk->sk_receive_queue);
91 skb_queue_purge(&sk->sk_error_queue);
94 static const struct can_proto *can_get_proto(int protocol)
96 const struct can_proto *cp;
99 cp = rcu_dereference(proto_tab[protocol]);
100 if (cp && !try_module_get(cp->prot->owner))
107 static inline void can_put_proto(const struct can_proto *cp)
109 module_put(cp->prot->owner);
112 static int can_create(struct net *net, struct socket *sock, int protocol,
116 const struct can_proto *cp;
119 sock->state = SS_UNCONNECTED;
121 if (protocol < 0 || protocol >= CAN_NPROTO)
124 cp = can_get_proto(protocol);
126 #ifdef CONFIG_MODULES
128 /* try to load protocol module if kernel is modular */
130 err = request_module("can-proto-%d", protocol);
132 /* In case of error we only print a message but don't
133 * return the error code immediately. Below we will
134 * return -EPROTONOSUPPORT
137 pr_err_ratelimited("can: request_module (can-proto-%d) failed.\n",
140 cp = can_get_proto(protocol);
144 /* check for available protocol and correct usage */
147 return -EPROTONOSUPPORT;
149 if (cp->type != sock->type) {
156 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern);
162 sock_init_data(sock, sk);
163 sk->sk_destruct = can_sock_destruct;
165 if (sk->sk_prot->init)
166 err = sk->sk_prot->init(sk);
169 /* release sk on errors */
182 * can_send - transmit a CAN frame (optional with local loopback)
183 * @skb: pointer to socket buffer with CAN frame in data section
184 * @loop: loopback for listeners on local CAN sockets (recommended default!)
186 * Due to the loopback this routine must not be called from hardirq context.
190 * -ENETDOWN when the selected interface is down
191 * -ENOBUFS on full driver queue (see net_xmit_errno())
192 * -ENOMEM when local loopback failed at calling skb_clone()
193 * -EPERM when trying to send on a non-CAN interface
194 * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
195 * -EINVAL when the skb->data does not contain a valid CAN frame
197 int can_send(struct sk_buff *skb, int loop)
199 struct sk_buff *newskb = NULL;
200 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
201 struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;
204 if (skb->len == CAN_MTU) {
205 skb->protocol = htons(ETH_P_CAN);
206 if (unlikely(cfd->len > CAN_MAX_DLEN))
208 } else if (skb->len == CANFD_MTU) {
209 skb->protocol = htons(ETH_P_CANFD);
210 if (unlikely(cfd->len > CANFD_MAX_DLEN))
216 /* Make sure the CAN frame can pass the selected CAN netdevice.
217 * As structs can_frame and canfd_frame are similar, we can provide
218 * CAN FD frames to legacy CAN drivers as long as the length is <= 8
220 if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
225 if (unlikely(skb->dev->type != ARPHRD_CAN)) {
230 if (unlikely(!(skb->dev->flags & IFF_UP))) {
235 skb->ip_summed = CHECKSUM_UNNECESSARY;
237 skb_reset_mac_header(skb);
238 skb_reset_network_header(skb);
239 skb_reset_transport_header(skb);
242 /* local loopback of sent CAN frames */
244 /* indication for the CAN driver: do loopback */
245 skb->pkt_type = PACKET_LOOPBACK;
247 /* The reference to the originating sock may be required
248 * by the receiving socket to check whether the frame is
249 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
250 * Therefore we have to ensure that skb->sk remains the
251 * reference to the originating sock by restoring skb->sk
252 * after each skb_clone() or skb_orphan() usage.
255 if (!(skb->dev->flags & IFF_ECHO)) {
256 /* If the interface is not capable to do loopback
257 * itself, we do it here.
259 newskb = skb_clone(skb, GFP_ATOMIC);
265 can_skb_set_owner(newskb, skb->sk);
266 newskb->ip_summed = CHECKSUM_UNNECESSARY;
267 newskb->pkt_type = PACKET_BROADCAST;
270 /* indication for the CAN driver: no loopback required */
271 skb->pkt_type = PACKET_HOST;
274 /* send to netdevice */
275 err = dev_queue_xmit(skb);
277 err = net_xmit_errno(err);
287 /* update statistics */
288 pkg_stats->tx_frames++;
289 pkg_stats->tx_frames_delta++;
297 EXPORT_SYMBOL(can_send);
301 static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net,
302 struct net_device *dev)
305 return net->can.rx_alldev_list;
307 return (struct can_dev_rcv_lists *)dev->ml_priv;
311 * effhash - hash function for 29 bit CAN identifier reduction
312 * @can_id: 29 bit CAN identifier
315 * To reduce the linear traversal in one linked list of _single_ EFF CAN
316 * frame subscriptions the 29 bit identifier is mapped to 10 bits.
317 * (see CAN_EFF_RCV_HASH_BITS definition)
320 * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
322 static unsigned int effhash(canid_t can_id)
327 hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
328 hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
330 return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
334 * can_rcv_list_find - determine optimal filterlist inside device filter struct
335 * @can_id: pointer to CAN identifier of a given can_filter
336 * @mask: pointer to CAN mask of a given can_filter
337 * @d: pointer to the device filter struct
340 * Returns the optimal filterlist to reduce the filter handling in the
341 * receive path. This function is called by service functions that need
342 * to register or unregister a can_filter in the filter lists.
344 * A filter matches in general, when
346 * <received_can_id> & mask == can_id & mask
348 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
349 * relevant bits for the filter.
351 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
352 * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
353 * frames there is a special filterlist and a special rx path filter handling.
356 * Pointer to optimal filterlist for the given can_id/mask pair.
357 * Constistency checked mask.
358 * Reduced can_id to have a preprocessed filter compare value.
360 static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
361 struct can_dev_rcv_lists *dev_rcv_lists)
363 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
365 /* filter for error message frames in extra filterlist */
366 if (*mask & CAN_ERR_FLAG) {
367 /* clear CAN_ERR_FLAG in filter entry */
368 *mask &= CAN_ERR_MASK;
369 return &dev_rcv_lists->rx[RX_ERR];
372 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
374 #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
376 /* ensure valid values in can_mask for 'SFF only' frame filtering */
377 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
378 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
380 /* reduce condition testing at receive time */
383 /* inverse can_id/can_mask filter */
385 return &dev_rcv_lists->rx[RX_INV];
387 /* mask == 0 => no condition testing at receive time */
389 return &dev_rcv_lists->rx[RX_ALL];
391 /* extra filterlists for the subscription of a single non-RTR can_id */
392 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
393 !(*can_id & CAN_RTR_FLAG)) {
394 if (*can_id & CAN_EFF_FLAG) {
395 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
396 return &dev_rcv_lists->rx_eff[effhash(*can_id)];
398 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
399 return &dev_rcv_lists->rx_sff[*can_id];
403 /* default: filter via can_id/can_mask */
404 return &dev_rcv_lists->rx[RX_FIL];
408 * can_rx_register - subscribe CAN frames from a specific interface
409 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
410 * @can_id: CAN identifier (see description)
411 * @mask: CAN mask (see description)
412 * @func: callback function on filter match
413 * @data: returned parameter for callback function
414 * @ident: string for calling module identification
415 * @sk: socket pointer (might be NULL)
418 * Invokes the callback function with the received sk_buff and the given
419 * parameter 'data' on a matching receive filter. A filter matches, when
421 * <received_can_id> & mask == can_id & mask
423 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
424 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
426 * The provided pointer to the sk_buff is guaranteed to be valid as long as
427 * the callback function is running. The callback function must *not* free
428 * the given sk_buff while processing it's task. When the given sk_buff is
429 * needed after the end of the callback function it must be cloned inside
430 * the callback function with skb_clone().
434 * -ENOMEM on missing cache mem to create subscription entry
435 * -ENODEV unknown device
437 int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
438 canid_t mask, void (*func)(struct sk_buff *, void *),
439 void *data, char *ident, struct sock *sk)
442 struct hlist_head *rl;
443 struct can_dev_rcv_lists *dev_rcv_lists;
444 struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
447 /* insert new receiver (dev,canid,mask) -> (func,data) */
449 if (dev && dev->type != ARPHRD_CAN)
452 if (dev && !net_eq(net, dev_net(dev)))
455 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
459 spin_lock(&net->can.rcvlists_lock);
461 dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
463 rl = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
473 hlist_add_head_rcu(&r->list, rl);
474 dev_rcv_lists->entries++;
476 rcv_lists_stats->rcv_entries++;
477 if (rcv_lists_stats->rcv_entries_max < rcv_lists_stats->rcv_entries)
478 rcv_lists_stats->rcv_entries_max = rcv_lists_stats->rcv_entries;
480 kmem_cache_free(rcv_cache, r);
484 spin_unlock(&net->can.rcvlists_lock);
488 EXPORT_SYMBOL(can_rx_register);
490 /* can_rx_delete_receiver - rcu callback for single receiver entry removal */
491 static void can_rx_delete_receiver(struct rcu_head *rp)
493 struct receiver *r = container_of(rp, struct receiver, rcu);
494 struct sock *sk = r->sk;
496 kmem_cache_free(rcv_cache, r);
502 * can_rx_unregister - unsubscribe CAN frames from a specific interface
503 * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
504 * @can_id: CAN identifier
506 * @func: callback function on filter match
507 * @data: returned parameter for callback function
510 * Removes subscription entry depending on given (subscription) values.
512 void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
513 canid_t mask, void (*func)(struct sk_buff *, void *),
516 struct receiver *r = NULL;
517 struct hlist_head *rl;
518 struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
519 struct can_dev_rcv_lists *dev_rcv_lists;
521 if (dev && dev->type != ARPHRD_CAN)
524 if (dev && !net_eq(net, dev_net(dev)))
527 spin_lock(&net->can.rcvlists_lock);
529 dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
530 if (!dev_rcv_lists) {
531 pr_err("BUG: receive list not found for dev %s, id %03X, mask %03X\n",
532 DNAME(dev), can_id, mask);
536 rl = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
538 /* Search the receiver list for the item to delete. This should
539 * exist, since no receiver may be unregistered that hasn't
540 * been registered before.
542 hlist_for_each_entry_rcu(r, rl, list) {
543 if (r->can_id == can_id && r->mask == mask &&
544 r->func == func && r->data == data)
548 /* Check for bugs in CAN protocol implementations using af_can.c:
549 * 'r' will be NULL if no matching list item was found for removal.
553 WARN(1, "BUG: receive list entry not found for dev %s, id %03X, mask %03X\n",
554 DNAME(dev), can_id, mask);
558 hlist_del_rcu(&r->list);
559 dev_rcv_lists->entries--;
561 if (rcv_lists_stats->rcv_entries > 0)
562 rcv_lists_stats->rcv_entries--;
564 /* remove device structure requested by NETDEV_UNREGISTER */
565 if (dev_rcv_lists->remove_on_zero_entries && !dev_rcv_lists->entries) {
566 kfree(dev_rcv_lists);
571 spin_unlock(&net->can.rcvlists_lock);
573 /* schedule the receiver item for deletion */
577 call_rcu(&r->rcu, can_rx_delete_receiver);
580 EXPORT_SYMBOL(can_rx_unregister);
582 static inline void deliver(struct sk_buff *skb, struct receiver *r)
584 r->func(skb, r->data);
588 static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb)
592 struct can_frame *cf = (struct can_frame *)skb->data;
593 canid_t can_id = cf->can_id;
595 if (dev_rcv_lists->entries == 0)
598 if (can_id & CAN_ERR_FLAG) {
599 /* check for error message frame entries only */
600 hlist_for_each_entry_rcu(r, &dev_rcv_lists->rx[RX_ERR], list) {
601 if (can_id & r->mask) {
609 /* check for unfiltered entries */
610 hlist_for_each_entry_rcu(r, &dev_rcv_lists->rx[RX_ALL], list) {
615 /* check for can_id/mask entries */
616 hlist_for_each_entry_rcu(r, &dev_rcv_lists->rx[RX_FIL], list) {
617 if ((can_id & r->mask) == r->can_id) {
623 /* check for inverted can_id/mask entries */
624 hlist_for_each_entry_rcu(r, &dev_rcv_lists->rx[RX_INV], list) {
625 if ((can_id & r->mask) != r->can_id) {
631 /* check filterlists for single non-RTR can_ids */
632 if (can_id & CAN_RTR_FLAG)
635 if (can_id & CAN_EFF_FLAG) {
636 hlist_for_each_entry_rcu(r, &dev_rcv_lists->rx_eff[effhash(can_id)], list) {
637 if (r->can_id == can_id) {
643 can_id &= CAN_SFF_MASK;
644 hlist_for_each_entry_rcu(r, &dev_rcv_lists->rx_sff[can_id], list) {
653 static void can_receive(struct sk_buff *skb, struct net_device *dev)
655 struct can_dev_rcv_lists *dev_rcv_lists;
656 struct net *net = dev_net(dev);
657 struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
660 /* update statistics */
661 pkg_stats->rx_frames++;
662 pkg_stats->rx_frames_delta++;
664 /* create non-zero unique skb identifier together with *skb */
665 while (!(can_skb_prv(skb)->skbcnt))
666 can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter);
670 /* deliver the packet to sockets listening on all devices */
671 matches = can_rcv_filter(net->can.rx_alldev_list, skb);
673 /* find receive list for this device */
674 dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
676 matches += can_rcv_filter(dev_rcv_lists, skb);
680 /* consume the skbuff allocated by the netdevice driver */
684 pkg_stats->matches++;
685 pkg_stats->matches_delta++;
689 static int can_rcv(struct sk_buff *skb, struct net_device *dev,
690 struct packet_type *pt, struct net_device *orig_dev)
692 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
694 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU ||
695 cfd->len > CAN_MAX_DLEN)) {
696 pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, datalen %d\n",
697 dev->type, skb->len, cfd->len);
702 can_receive(skb, dev);
703 return NET_RX_SUCCESS;
706 static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
707 struct packet_type *pt, struct net_device *orig_dev)
709 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
711 if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU ||
712 cfd->len > CANFD_MAX_DLEN)) {
713 pr_warn_once("PF_CAN: dropped non conform CAN FD skbuf: dev type %d, len %d, datalen %d\n",
714 dev->type, skb->len, cfd->len);
719 can_receive(skb, dev);
720 return NET_RX_SUCCESS;
723 /* af_can protocol functions */
726 * can_proto_register - register CAN transport protocol
727 * @cp: pointer to CAN protocol structure
731 * -EINVAL invalid (out of range) protocol number
732 * -EBUSY protocol already in use
733 * -ENOBUF if proto_register() fails
735 int can_proto_register(const struct can_proto *cp)
737 int proto = cp->protocol;
740 if (proto < 0 || proto >= CAN_NPROTO) {
741 pr_err("can: protocol number %d out of range\n", proto);
745 err = proto_register(cp->prot, 0);
749 mutex_lock(&proto_tab_lock);
751 if (rcu_access_pointer(proto_tab[proto])) {
752 pr_err("can: protocol %d already registered\n", proto);
755 RCU_INIT_POINTER(proto_tab[proto], cp);
758 mutex_unlock(&proto_tab_lock);
761 proto_unregister(cp->prot);
765 EXPORT_SYMBOL(can_proto_register);
768 * can_proto_unregister - unregister CAN transport protocol
769 * @cp: pointer to CAN protocol structure
771 void can_proto_unregister(const struct can_proto *cp)
773 int proto = cp->protocol;
775 mutex_lock(&proto_tab_lock);
776 BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp);
777 RCU_INIT_POINTER(proto_tab[proto], NULL);
778 mutex_unlock(&proto_tab_lock);
782 proto_unregister(cp->prot);
784 EXPORT_SYMBOL(can_proto_unregister);
786 /* af_can notifier to create/remove CAN netdevice specific structs */
787 static int can_notifier(struct notifier_block *nb, unsigned long msg,
790 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
791 struct can_dev_rcv_lists *dev_rcv_lists;
793 if (dev->type != ARPHRD_CAN)
797 case NETDEV_REGISTER:
799 /* create new dev_rcv_lists for this device */
800 dev_rcv_lists = kzalloc(sizeof(*dev_rcv_lists), GFP_KERNEL);
803 BUG_ON(dev->ml_priv);
804 dev->ml_priv = dev_rcv_lists;
808 case NETDEV_UNREGISTER:
809 spin_lock(&dev_net(dev)->can.rcvlists_lock);
811 dev_rcv_lists = dev->ml_priv;
813 if (dev_rcv_lists->entries)
814 dev_rcv_lists->remove_on_zero_entries = 1;
816 kfree(dev_rcv_lists);
820 pr_err("can: notifier: receive list not found for dev %s\n",
824 spin_unlock(&dev_net(dev)->can.rcvlists_lock);
832 static int can_pernet_init(struct net *net)
834 spin_lock_init(&net->can.rcvlists_lock);
835 net->can.rx_alldev_list =
836 kzalloc(sizeof(*net->can.rx_alldev_list), GFP_KERNEL);
837 if (!net->can.rx_alldev_list)
839 net->can.pkg_stats = kzalloc(sizeof(*net->can.pkg_stats), GFP_KERNEL);
840 if (!net->can.pkg_stats)
841 goto out_free_rx_alldev_list;
842 net->can.rcv_lists_stats = kzalloc(sizeof(*net->can.rcv_lists_stats), GFP_KERNEL);
843 if (!net->can.rcv_lists_stats)
844 goto out_free_pkg_stats;
846 if (IS_ENABLED(CONFIG_PROC_FS)) {
847 /* the statistics are updated every second (timer triggered) */
849 timer_setup(&net->can.stattimer, can_stat_update,
851 mod_timer(&net->can.stattimer,
852 round_jiffies(jiffies + HZ));
854 net->can.pkg_stats->jiffies_init = jiffies;
861 kfree(net->can.pkg_stats);
862 out_free_rx_alldev_list:
863 kfree(net->can.rx_alldev_list);
868 static void can_pernet_exit(struct net *net)
870 struct net_device *dev;
872 if (IS_ENABLED(CONFIG_PROC_FS)) {
873 can_remove_proc(net);
875 del_timer_sync(&net->can.stattimer);
878 /* remove created dev_rcv_lists from still registered CAN devices */
880 for_each_netdev_rcu(net, dev) {
881 if (dev->type == ARPHRD_CAN && dev->ml_priv) {
882 struct can_dev_rcv_lists *dev_rcv_lists = dev->ml_priv;
884 BUG_ON(dev_rcv_lists->entries);
885 kfree(dev_rcv_lists);
891 kfree(net->can.rx_alldev_list);
892 kfree(net->can.pkg_stats);
893 kfree(net->can.rcv_lists_stats);
896 /* af_can module init/exit functions */
898 static struct packet_type can_packet __read_mostly = {
899 .type = cpu_to_be16(ETH_P_CAN),
903 static struct packet_type canfd_packet __read_mostly = {
904 .type = cpu_to_be16(ETH_P_CANFD),
908 static const struct net_proto_family can_family_ops = {
910 .create = can_create,
911 .owner = THIS_MODULE,
914 /* notifier block for netdevice event */
915 static struct notifier_block can_netdev_notifier __read_mostly = {
916 .notifier_call = can_notifier,
919 static struct pernet_operations can_pernet_ops __read_mostly = {
920 .init = can_pernet_init,
921 .exit = can_pernet_exit,
924 static __init int can_init(void)
928 /* check for correct padding to be able to use the structs similarly */
929 BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
930 offsetof(struct canfd_frame, len) ||
931 offsetof(struct can_frame, data) !=
932 offsetof(struct canfd_frame, data));
934 pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n");
936 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
941 err = register_pernet_subsys(&can_pernet_ops);
945 /* protocol register */
946 err = sock_register(&can_family_ops);
949 err = register_netdevice_notifier(&can_netdev_notifier);
953 dev_add_pack(&can_packet);
954 dev_add_pack(&canfd_packet);
959 sock_unregister(PF_CAN);
961 unregister_pernet_subsys(&can_pernet_ops);
963 kmem_cache_destroy(rcv_cache);
968 static __exit void can_exit(void)
970 /* protocol unregister */
971 dev_remove_pack(&canfd_packet);
972 dev_remove_pack(&can_packet);
973 unregister_netdevice_notifier(&can_netdev_notifier);
974 sock_unregister(PF_CAN);
976 unregister_pernet_subsys(&can_pernet_ops);
978 rcu_barrier(); /* Wait for completion of call_rcu()'s */
980 kmem_cache_destroy(rcv_cache);
983 module_init(can_init);
984 module_exit(can_exit);