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()
174 		sock->sk = NULL;  in can_create()
185  * can_send - transmit a CAN frame (optional with local loopback)
193  *  -ENETDOWN when the selected interface is down
194  *  -ENOBUFS on full driver queue (see net_xmit_errno())
195  *  -ENOMEM when local loopback failed at calling skb_clone()
196  *  -EPERM when trying to send on a non-CAN interface
197  *  -EMSGSIZE CAN frame size is bigger than CAN interface MTU
198  *  -EINVAL when the skb->data does not contain a valid CAN frame
203 	struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;  in can_send()
204 	int err = -EINVAL;  in can_send()
207 		skb->protocol = htons(ETH_P_CANXL);  in can_send()
209 		skb->protocol = htons(ETH_P_CAN);  in can_send()
211 		struct canfd_frame *cfd = (struct canfd_frame *)skb->data;  in can_send()
213 		skb->protocol = htons(ETH_P_CANFD);  in can_send()
216 		cfd->flags |= CANFD_FDF;  in can_send()
222 	if (unlikely(skb->len > skb->dev->mtu)) {  in can_send()
223 		err = -EMSGSIZE;  in can_send()
227 	if (unlikely(skb->dev->type != ARPHRD_CAN)) {  in can_send()
228 		err = -EPERM;  in can_send()
232 	if (unlikely(!(skb->dev->flags & IFF_UP))) {  in can_send()
233 		err = -ENETDOWN;  in can_send()
237 	skb->ip_summed = CHECKSUM_UNNECESSARY;  in can_send()
247 		skb->pkt_type = PACKET_LOOPBACK;  in can_send()
252 		 * Therefore we have to ensure that skb->sk remains the  in can_send()
253 		 * reference to the originating sock by restoring skb->sk  in can_send()
257 		if (!(skb->dev->flags & IFF_ECHO)) {  in can_send()
264 				return -ENOMEM;  in can_send()
267 			can_skb_set_owner(newskb, skb->sk);  in can_send()
268 			newskb->ip_summed = CHECKSUM_UNNECESSARY;  in can_send()
269 			newskb->pkt_type = PACKET_BROADCAST;  in can_send()
273 		skb->pkt_type = PACKET_HOST;  in can_send()
290 	atomic_long_inc(&pkg_stats->tx_frames);  in can_send()
291 	atomic_long_inc(&pkg_stats->tx_frames_delta);  in can_send()
301 /* af_can rx path */
308 		return &can_ml->dev_rcv_lists;  in can_dev_rcv_lists_find()
310 		return net->can.rx_alldev_list;  in can_dev_rcv_lists_find()
315  * effhash - hash function for 29 bit CAN identifier reduction
324  *  Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
334 	return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);  in effhash()
338  * can_rcv_list_find - determine optimal filterlist inside device filter struct
355  *  The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
357  *  frames there is a special filterlist and a special rx path filter handling.
373 		return &dev_rcv_lists->rx[RX_ERR];  in can_rcv_list_find()
389 		return &dev_rcv_lists->rx[RX_INV];  in can_rcv_list_find()
393 		return &dev_rcv_lists->rx[RX_ALL];  in can_rcv_list_find()
395 	/* extra filterlists for the subscription of a single non-RTR can_id */  in can_rcv_list_find()
400 				return &dev_rcv_lists->rx_eff[effhash(*can_id)];  in can_rcv_list_find()
403 				return &dev_rcv_lists->rx_sff[*can_id];  in can_rcv_list_find()
408 	return &dev_rcv_lists->rx[RX_FIL];  in can_rcv_list_find()
412  * can_rx_register - subscribe CAN frames from a specific interface
428  *  The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
439  *  -ENOMEM on missing cache mem to create subscription entry
440  *  -ENODEV unknown device
449 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;  in can_rx_register()
451 	/* insert new receiver  (dev,canid,mask) -> (func,data) */  in can_rx_register()
453 	if (dev && (dev->type != ARPHRD_CAN || !can_get_ml_priv(dev)))  in can_rx_register()
454 		return -ENODEV;  in can_rx_register()
457 		return -ENODEV;  in can_rx_register()
461 		return -ENOMEM;  in can_rx_register()
463 	spin_lock_bh(&net->can.rcvlists_lock);  in can_rx_register()
468 	rcv->can_id = can_id;  in can_rx_register()
469 	rcv->mask = mask;  in can_rx_register()
470 	rcv->matches = 0;  in can_rx_register()
471 	rcv->func = func;  in can_rx_register()
472 	rcv->data = data;  in can_rx_register()
473 	rcv->ident = ident;  in can_rx_register()
474 	rcv->sk = sk;  in can_rx_register()
476 	hlist_add_head_rcu(&rcv->list, rcv_list);  in can_rx_register()
477 	dev_rcv_lists->entries++;  in can_rx_register()
479 	rcv_lists_stats->rcv_entries++;  in can_rx_register()
480 	rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max,  in can_rx_register()
481 					       rcv_lists_stats->rcv_entries);  in can_rx_register()
482 	spin_unlock_bh(&net->can.rcvlists_lock);  in can_rx_register()
488 /* can_rx_delete_receiver - rcu callback for single receiver entry removal */
492 	struct sock *sk = rcv->sk;  in can_rx_delete_receiver()
500  * can_rx_unregister - unsubscribe CAN frames from a specific interface
517 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;  in can_rx_unregister()
520 	if (dev && dev->type != ARPHRD_CAN)  in can_rx_unregister()
526 	spin_lock_bh(&net->can.rcvlists_lock);  in can_rx_unregister()
536 		if (rcv->can_id == can_id && rcv->mask == mask &&  in can_rx_unregister()
537 		    rcv->func == func && rcv->data == data)  in can_rx_unregister()
553 	hlist_del_rcu(&rcv->list);  in can_rx_unregister()
554 	dev_rcv_lists->entries--;  in can_rx_unregister()
556 	if (rcv_lists_stats->rcv_entries > 0)  in can_rx_unregister()
557 		rcv_lists_stats->rcv_entries--;  in can_rx_unregister()
560 	spin_unlock_bh(&net->can.rcvlists_lock);  in can_rx_unregister()
564 		if (rcv->sk)  in can_rx_unregister()
565 			sock_hold(rcv->sk);  in can_rx_unregister()
566 		call_rcu(&rcv->rcu, can_rx_delete_receiver);  in can_rx_unregister()
573 	rcv->func(skb, rcv->data);  in deliver()
574 	rcv->matches++;  in deliver()
581 	struct can_frame *cf = (struct can_frame *)skb->data;  in can_rcv_filter()
582 	canid_t can_id = cf->can_id;  in can_rcv_filter()
584 	if (dev_rcv_lists->entries == 0)  in can_rcv_filter()
589 		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) {  in can_rcv_filter()
590 			if (can_id & rcv->mask) {  in can_rcv_filter()
599 	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) {  in can_rcv_filter()
605 	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) {  in can_rcv_filter()
606 		if ((can_id & rcv->mask) == rcv->can_id) {  in can_rcv_filter()
612 	/* check for inverted can_id/mask entries */  in can_rcv_filter()
613 	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) {  in can_rcv_filter()
614 		if ((can_id & rcv->mask) != rcv->can_id) {  in can_rcv_filter()
620 	/* check filterlists for single non-RTR can_ids */  in can_rcv_filter()
625 		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) {  in can_rcv_filter()
626 			if (rcv->can_id == can_id) {  in can_rcv_filter()
633 		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) {  in can_rcv_filter()
646 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;  in can_receive()
650 	atomic_long_inc(&pkg_stats->rx_frames);  in can_receive()
651 	atomic_long_inc(&pkg_stats->rx_frames_delta);  in can_receive()
653 	/* create non-zero unique skb identifier together with *skb */  in can_receive()
654 	while (!(can_skb_prv(skb)->skbcnt))  in can_receive()
655 		can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter);  in can_receive()
660 	matches = can_rcv_filter(net->can.rx_alldev_list, skb);  in can_receive()
672 		atomic_long_inc(&pkg_stats->matches);  in can_receive()
673 		atomic_long_inc(&pkg_stats->matches_delta);  in can_receive()
680 	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_can_skb(skb))) {  in can_rcv()
682 			     dev->type, skb->len);  in can_rcv()
695 	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_canfd_skb(skb))) {  in canfd_rcv()
697 			     dev->type, skb->len);  in canfd_rcv()
710 	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) || !can_is_canxl_skb(skb))) {  in canxl_rcv()
712 			     dev->type, skb->len);  in canxl_rcv()
725  * can_proto_register - register CAN transport protocol
730  *  -EINVAL invalid (out of range) protocol number
731  *  -EBUSY  protocol already in use
732  *  -ENOBUF if proto_register() fails
736 	int proto = cp->protocol;  in can_proto_register()
741 		return -EINVAL;  in can_proto_register()
744 	err = proto_register(cp->prot, 0);  in can_proto_register()
752 		err = -EBUSY;  in can_proto_register()
760 		proto_unregister(cp->prot);  in can_proto_register()
767  * can_proto_unregister - unregister CAN transport protocol
772 	int proto = cp->protocol;  in can_proto_unregister()
781 	proto_unregister(cp->prot);  in can_proto_unregister()
787 	spin_lock_init(&net->can.rcvlists_lock);  in can_pernet_init()
788 	net->can.rx_alldev_list =  in can_pernet_init()
789 		kzalloc(sizeof(*net->can.rx_alldev_list), GFP_KERNEL);  in can_pernet_init()
790 	if (!net->can.rx_alldev_list)  in can_pernet_init()
792 	net->can.pkg_stats = kzalloc(sizeof(*net->can.pkg_stats), GFP_KERNEL);  in can_pernet_init()
793 	if (!net->can.pkg_stats)  in can_pernet_init()
795 	net->can.rcv_lists_stats = kzalloc(sizeof(*net->can.rcv_lists_stats), GFP_KERNEL);  in can_pernet_init()
796 	if (!net->can.rcv_lists_stats)  in can_pernet_init()
802 			timer_setup(&net->can.stattimer, can_stat_update,  in can_pernet_init()
804 			mod_timer(&net->can.stattimer,  in can_pernet_init()
807 		net->can.pkg_stats->jiffies_init = jiffies;  in can_pernet_init()
814 	kfree(net->can.pkg_stats);  in can_pernet_init()
816 	kfree(net->can.rx_alldev_list);  in can_pernet_init()
818 	return -ENOMEM;  in can_pernet_init()
826 			del_timer_sync(&net->can.stattimer);  in can_pernet_exit()
829 	kfree(net->can.rx_alldev_list);  in can_pernet_exit()
830 	kfree(net->can.pkg_stats);  in can_pernet_exit()
831 	kfree(net->can.rcv_lists_stats);  in can_pernet_exit()
879 		return -ENOMEM;  in can_init()