1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /* af_can.c - Protocol family CAN core module
5  * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
61 #include <linux/can/can-ml.h>
91 	skb_queue_purge(&sk->sk_receive_queue);  in can_sock_destruct()
92 	skb_queue_purge(&sk->sk_error_queue);  in can_sock_destruct()
102 	if (cp && !try_module_get(cp->prot->owner))  in can_get_proto()
111 	module_put(cp->prot->owner);  in can_put_proto()
121 	sock->state = SS_UNCONNECTED;  in can_create()
124 		return -EINVAL;  in can_create()
132 		err = request_module("can-proto-%d", protocol);  in can_create()
136 		 * return -EPROTONOSUPPORT  in can_create()
139 			pr_err_ratelimited("can: request_module (can-proto-%d) failed.\n",  in can_create()
149 		return -EPROTONOSUPPORT;  in can_create()
151 	if (cp->type != sock->type) {  in can_create()
152 		err = -EPROTOTYPE;  in can_create()
156 	sock->ops = cp->ops;  in can_create()
158 	sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern);  in can_create()
160 		err = -ENOMEM;  in can_create()
165 	sk->sk_destruct = can_sock_destruct;  in can_create()
167 	if (sk->sk_prot->init)  in can_create()
168 		err = sk->sk_prot->init(sk);  in can_create()
184  * can_send - transmit a CAN frame (optional with local loopback)
192  *  -ENETDOWN when the selected interface is down
193  *  -ENOBUFS on full driver queue (see net_xmit_errno())
194  *  -ENOMEM when local loopback failed at calling skb_clone()
195  *  -EPERM when trying to send on a non-CAN interface
196  *  -EMSGSIZE CAN frame size is bigger than CAN interface MTU
197  *  -EINVAL when the skb->data does not contain a valid CAN frame
202 	struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;  in can_send()
203 	int err = -EINVAL;  in can_send()
206 		skb->protocol = htons(ETH_P_CANXL);  in can_send()
208 		skb->protocol = htons(ETH_P_CAN);  in can_send()
210 		struct canfd_frame *cfd = (struct canfd_frame *)skb->data;  in can_send()
212 		skb->protocol = htons(ETH_P_CANFD);  in can_send()
215 		cfd->flags |= CANFD_FDF;  in can_send()
221 	if (unlikely(skb->len > skb->dev->mtu)) {  in can_send()
222 		err = -EMSGSIZE;  in can_send()
226 	if (unlikely(skb->dev->type != ARPHRD_CAN)) {  in can_send()
227 		err = -EPERM;  in can_send()
231 	if (unlikely(!(skb->dev->flags & IFF_UP))) {  in can_send()
232 		err = -ENETDOWN;  in can_send()
236 	skb->ip_summed = CHECKSUM_UNNECESSARY;  in can_send()
246 		skb->pkt_type = PACKET_LOOPBACK;  in can_send()
251 		 * Therefore we have to ensure that skb->sk remains the  in can_send()
252 		 * reference to the originating sock by restoring skb->sk  in can_send()
256 		if (!(skb->dev->flags & IFF_ECHO)) {  in can_send()
263 				return -ENOMEM;  in can_send()
266 			can_skb_set_owner(newskb, skb->sk);  in can_send()
267 			newskb->ip_summed = CHECKSUM_UNNECESSARY;  in can_send()
268 			newskb->pkt_type = PACKET_BROADCAST;  in can_send()
272 		skb->pkt_type = PACKET_HOST;  in can_send()
289 	pkg_stats->tx_frames++;  in can_send()
290 	pkg_stats->tx_frames_delta++;  in can_send()
307 		return &can_ml->dev_rcv_lists;  in can_dev_rcv_lists_find()
309 		return net->can.rx_alldev_list;  in can_dev_rcv_lists_find()
314  * effhash - hash function for 29 bit CAN identifier reduction
323  *  Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
333 	return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);  in effhash()
337  * can_rcv_list_find - determine optimal filterlist inside device filter struct
339  * @mask: pointer to CAN mask of a given can_filter
344  *  receive path. This function is called by service functions that need
349  *          <received_can_id> & mask == can_id & mask
351  *  so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
355  *  filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
359  *  Pointer to optimal filterlist for the given can_id/mask pair.
360  *  Consistency checked mask.
363 static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,  in can_rcv_list_find()  argument
369 	if (*mask & CAN_ERR_FLAG) {  in can_rcv_list_find()
371 		*mask &= CAN_ERR_MASK;  in can_rcv_list_find()
372 		return &dev_rcv_lists->rx[RX_ERR];  in can_rcv_list_find()
375 	/* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */  in can_rcv_list_find()
380 	if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))  in can_rcv_list_find()
381 		*mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);  in can_rcv_list_find()
384 	*can_id &= *mask;  in can_rcv_list_find()
388 		return &dev_rcv_lists->rx[RX_INV];  in can_rcv_list_find()
390 	/* mask == 0 => no condition testing at receive time */  in can_rcv_list_find()
391 	if (!(*mask))  in can_rcv_list_find()
392 		return &dev_rcv_lists->rx[RX_ALL];  in can_rcv_list_find()
394 	/* extra filterlists for the subscription of a single non-RTR can_id */  in can_rcv_list_find()
395 	if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&  in can_rcv_list_find()
398 			if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))  in can_rcv_list_find()
399 				return &dev_rcv_lists->rx_eff[effhash(*can_id)];  in can_rcv_list_find()
401 			if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))  in can_rcv_list_find()
402 				return &dev_rcv_lists->rx_sff[*can_id];  in can_rcv_list_find()
407 	return &dev_rcv_lists->rx[RX_FIL];  in can_rcv_list_find()
411  * can_rx_register - subscribe CAN frames from a specific interface
415  * @mask: CAN mask (see description)
416  * @func: callback function on filter match
417  * @data: returned parameter for callback function
422  *  Invokes the callback function with the received sk_buff and the given
425  *          <received_can_id> & mask == can_id & mask
428  *  filter for error message frames (CAN_ERR_FLAG bit set in mask).
431  *  the callback function is running. The callback function must *not* free
433  *  needed after the end of the callback function it must be cloned inside
434  *  the callback function with skb_clone().
438  *  -ENOMEM on missing cache mem to create subscription entry
439  *  -ENODEV unknown device
442 		    canid_t mask, void (*func)(struct sk_buff *, void *),  in can_rx_register()  argument
448 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;  in can_rx_register()
450 	/* insert new receiver  (dev,canid,mask) -> (func,data) */  in can_rx_register()
452 	if (dev && (dev->type != ARPHRD_CAN || !can_get_ml_priv(dev)))  in can_rx_register()
453 		return -ENODEV;  in can_rx_register()
456 		return -ENODEV;  in can_rx_register()
460 		return -ENOMEM;  in can_rx_register()
462 	spin_lock_bh(&net->can.rcvlists_lock);  in can_rx_register()
465 	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);  in can_rx_register()
467 	rcv->can_id = can_id;  in can_rx_register()
468 	rcv->mask = mask;  in can_rx_register()
469 	rcv->matches = 0;  in can_rx_register()
470 	rcv->func = func;  in can_rx_register()
471 	rcv->data = data;  in can_rx_register()
472 	rcv->ident = ident;  in can_rx_register()
473 	rcv->sk = sk;  in can_rx_register()
475 	hlist_add_head_rcu(&rcv->list, rcv_list);  in can_rx_register()
476 	dev_rcv_lists->entries++;  in can_rx_register()
478 	rcv_lists_stats->rcv_entries++;  in can_rx_register()
479 	rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max,  in can_rx_register()
480 					       rcv_lists_stats->rcv_entries);  in can_rx_register()
481 	spin_unlock_bh(&net->can.rcvlists_lock);  in can_rx_register()
487 /* can_rx_delete_receiver - rcu callback for single receiver entry removal */
491 	struct sock *sk = rcv->sk;  in can_rx_delete_receiver()
499  * can_rx_unregister - unsubscribe CAN frames from a specific interface
503  * @mask: CAN mask
504  * @func: callback function on filter match
505  * @data: returned parameter for callback function
511 		       canid_t mask, void (*func)(struct sk_buff *, void *),  in can_rx_unregister()  argument
516 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;  in can_rx_unregister()
519 	if (dev && dev->type != ARPHRD_CAN)  in can_rx_unregister()
525 	spin_lock_bh(&net->can.rcvlists_lock);  in can_rx_unregister()
528 	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);  in can_rx_unregister()
535 		if (rcv->can_id == can_id && rcv->mask == mask &&  in can_rx_unregister()
536 		    rcv->func == func && rcv->data == data)  in can_rx_unregister()
547 		pr_warn("can: receive list entry not found for dev %s, id %03X, mask %03X\n",  in can_rx_unregister()
548 			DNAME(dev), can_id, mask);  in can_rx_unregister()
552 	hlist_del_rcu(&rcv->list);  in can_rx_unregister()
553 	dev_rcv_lists->entries--;  in can_rx_unregister()
555 	if (rcv_lists_stats->rcv_entries > 0)  in can_rx_unregister()
556 		rcv_lists_stats->rcv_entries--;  in can_rx_unregister()
559 	spin_unlock_bh(&net->can.rcvlists_lock);  in can_rx_unregister()
563 		if (rcv->sk)  in can_rx_unregister()
564 			sock_hold(rcv->sk);  in can_rx_unregister()
565 		call_rcu(&rcv->rcu, can_rx_delete_receiver);  in can_rx_unregister()
572 	rcv->func(skb, rcv->data);  in deliver()
573 	rcv->matches++;  in deliver()
580 	struct can_frame *cf = (struct can_frame *)skb->data;  in can_rcv_filter()
581 	canid_t can_id = cf->can_id;  in can_rcv_filter()
583 	if (dev_rcv_lists->entries == 0)  in can_rcv_filter()
588 		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) {  in can_rcv_filter()
589 			if (can_id & rcv->mask) {  in can_rcv_filter()
598 	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) {  in can_rcv_filter()
603 	/* check for can_id/mask entries */  in can_rcv_filter()
604 	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) {  in can_rcv_filter()
605 		if ((can_id & rcv->mask) == rcv->can_id) {  in can_rcv_filter()
611 	/* check for inverted can_id/mask entries */  in can_rcv_filter()
612 	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) {  in can_rcv_filter()
613 		if ((can_id & rcv->mask) != rcv->can_id) {  in can_rcv_filter()
619 	/* check filterlists for single non-RTR can_ids */  in can_rcv_filter()
624 		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) {  in can_rcv_filter()
625 			if (rcv->can_id == can_id) {  in can_rcv_filter()
632 		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) {  in can_rcv_filter()
645 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;  in can_receive()
649 	pkg_stats->rx_frames++;  in can_receive()
650 	pkg_stats->rx_frames_delta++;  in can_receive()
652 	/* create non-zero unique skb identifier together with *skb */  in can_receive()
653 	while (!(can_skb_prv(skb)->skbcnt))  in can_receive()
654 		can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter);  in can_receive()
659 	matches = can_rcv_filter(net->can.rx_alldev_list, skb);  in can_receive()
671 		pkg_stats->matches++;  in can_receive()
672 		pkg_stats->matches_delta++;  in can_receive()
679 	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_can_skb(skb))) {  in can_rcv()
681 			     dev->type, skb->len);  in can_rcv()
694 	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_canfd_skb(skb))) {  in canfd_rcv()
696 			     dev->type, skb->len);  in canfd_rcv()
709 	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_canxl_skb(skb))) {  in canxl_rcv()
711 			     dev->type, skb->len);  in canxl_rcv()
724  * can_proto_register - register CAN transport protocol
729  *  -EINVAL invalid (out of range) protocol number
730  *  -EBUSY  protocol already in use
731  *  -ENOBUF if proto_register() fails
735 	int proto = cp->protocol;  in can_proto_register()
740 		return -EINVAL;  in can_proto_register()
743 	err = proto_register(cp->prot, 0);  in can_proto_register()
751 		err = -EBUSY;  in can_proto_register()
759 		proto_unregister(cp->prot);  in can_proto_register()
766  * can_proto_unregister - unregister CAN transport protocol
771 	int proto = cp->protocol;  in can_proto_unregister()
780 	proto_unregister(cp->prot);  in can_proto_unregister()
786 	spin_lock_init(&net->can.rcvlists_lock);  in can_pernet_init()
787 	net->can.rx_alldev_list =  in can_pernet_init()
788 		kzalloc(sizeof(*net->can.rx_alldev_list), GFP_KERNEL);  in can_pernet_init()
789 	if (!net->can.rx_alldev_list)  in can_pernet_init()
791 	net->can.pkg_stats = kzalloc(sizeof(*net->can.pkg_stats), GFP_KERNEL);  in can_pernet_init()
792 	if (!net->can.pkg_stats)  in can_pernet_init()
794 	net->can.rcv_lists_stats = kzalloc(sizeof(*net->can.rcv_lists_stats), GFP_KERNEL);  in can_pernet_init()
795 	if (!net->can.rcv_lists_stats)  in can_pernet_init()
801 			timer_setup(&net->can.stattimer, can_stat_update,  in can_pernet_init()
803 			mod_timer(&net->can.stattimer,  in can_pernet_init()
806 		net->can.pkg_stats->jiffies_init = jiffies;  in can_pernet_init()
813 	kfree(net->can.pkg_stats);  in can_pernet_init()
815 	kfree(net->can.rx_alldev_list);  in can_pernet_init()
817 	return -ENOMEM;  in can_pernet_init()
825 			del_timer_sync(&net->can.stattimer);  in can_pernet_exit()
828 	kfree(net->can.rx_alldev_list);  in can_pernet_exit()
829 	kfree(net->can.pkg_stats);  in can_pernet_exit()
830 	kfree(net->can.rcv_lists_stats);  in can_pernet_exit()
876 		return -ENOMEM;  in can_init()