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919 lines
25 KiB
919 lines
25 KiB
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) |
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/* af_can.c - Protocol family CAN core module |
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* (used by different CAN protocol modules) |
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* |
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* Copyright (c) 2002-2017 Volkswagen Group Electronic Research |
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* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of Volkswagen nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* Alternatively, provided that this notice is retained in full, this |
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* software may be distributed under the terms of the GNU General |
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* Public License ("GPL") version 2, in which case the provisions of the |
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* GPL apply INSTEAD OF those given above. |
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* |
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* The provided data structures and external interfaces from this code |
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* are not restricted to be used by modules with a GPL compatible license. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
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* DAMAGE. |
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* |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/stddef.h> |
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#include <linux/init.h> |
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#include <linux/kmod.h> |
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#include <linux/slab.h> |
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#include <linux/list.h> |
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#include <linux/spinlock.h> |
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#include <linux/rcupdate.h> |
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#include <linux/uaccess.h> |
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#include <linux/net.h> |
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#include <linux/netdevice.h> |
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#include <linux/socket.h> |
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#include <linux/if_ether.h> |
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#include <linux/if_arp.h> |
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#include <linux/skbuff.h> |
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#include <linux/can.h> |
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#include <linux/can/core.h> |
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#include <linux/can/skb.h> |
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#include <linux/can/can-ml.h> |
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#include <linux/ratelimit.h> |
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#include <net/net_namespace.h> |
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#include <net/sock.h> |
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|
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#include "af_can.h" |
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|
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MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); |
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MODULE_LICENSE("Dual BSD/GPL"); |
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MODULE_AUTHOR("Urs Thuermann <[email protected]>, " |
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"Oliver Hartkopp <[email protected]>"); |
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|
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MODULE_ALIAS_NETPROTO(PF_CAN); |
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|
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static int stats_timer __read_mostly = 1; |
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module_param(stats_timer, int, 0444); |
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MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); |
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|
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static struct kmem_cache *rcv_cache __read_mostly; |
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|
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/* table of registered CAN protocols */ |
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static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly; |
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static DEFINE_MUTEX(proto_tab_lock); |
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|
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static atomic_t skbcounter = ATOMIC_INIT(0); |
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|
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/* af_can socket functions */ |
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|
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void can_sock_destruct(struct sock *sk) |
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{ |
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skb_queue_purge(&sk->sk_receive_queue); |
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skb_queue_purge(&sk->sk_error_queue); |
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} |
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EXPORT_SYMBOL(can_sock_destruct); |
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|
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static const struct can_proto *can_get_proto(int protocol) |
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{ |
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const struct can_proto *cp; |
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|
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rcu_read_lock(); |
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cp = rcu_dereference(proto_tab[protocol]); |
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if (cp && !try_module_get(cp->prot->owner)) |
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cp = NULL; |
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rcu_read_unlock(); |
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|
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return cp; |
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} |
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|
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static inline void can_put_proto(const struct can_proto *cp) |
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{ |
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module_put(cp->prot->owner); |
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} |
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|
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static int can_create(struct net *net, struct socket *sock, int protocol, |
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int kern) |
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{ |
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struct sock *sk; |
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const struct can_proto *cp; |
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int err = 0; |
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|
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sock->state = SS_UNCONNECTED; |
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|
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if (protocol < 0 || protocol >= CAN_NPROTO) |
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return -EINVAL; |
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cp = can_get_proto(protocol); |
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|
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#ifdef CONFIG_MODULES |
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if (!cp) { |
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/* try to load protocol module if kernel is modular */ |
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err = request_module("can-proto-%d", protocol); |
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|
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/* In case of error we only print a message but don't |
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* return the error code immediately. Below we will |
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* return -EPROTONOSUPPORT |
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*/ |
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if (err) |
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pr_err_ratelimited("can: request_module (can-proto-%d) failed.\n", |
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protocol); |
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cp = can_get_proto(protocol); |
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} |
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#endif |
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|
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/* check for available protocol and correct usage */ |
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|
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if (!cp) |
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return -EPROTONOSUPPORT; |
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|
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if (cp->type != sock->type) { |
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err = -EPROTOTYPE; |
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goto errout; |
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} |
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sock->ops = cp->ops; |
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|
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sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern); |
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if (!sk) { |
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err = -ENOMEM; |
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goto errout; |
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} |
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sock_init_data(sock, sk); |
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sk->sk_destruct = can_sock_destruct; |
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if (sk->sk_prot->init) |
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err = sk->sk_prot->init(sk); |
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if (err) { |
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/* release sk on errors */ |
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sock_orphan(sk); |
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sock_put(sk); |
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} |
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errout: |
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can_put_proto(cp); |
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return err; |
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} |
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/* af_can tx path */ |
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/** |
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* can_send - transmit a CAN frame (optional with local loopback) |
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* @skb: pointer to socket buffer with CAN frame in data section |
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* @loop: loopback for listeners on local CAN sockets (recommended default!) |
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* |
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* Due to the loopback this routine must not be called from hardirq context. |
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* |
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* Return: |
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* 0 on success |
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* -ENETDOWN when the selected interface is down |
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* -ENOBUFS on full driver queue (see net_xmit_errno()) |
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* -ENOMEM when local loopback failed at calling skb_clone() |
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* -EPERM when trying to send on a non-CAN interface |
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* -EMSGSIZE CAN frame size is bigger than CAN interface MTU |
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* -EINVAL when the skb->data does not contain a valid CAN frame |
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*/ |
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int can_send(struct sk_buff *skb, int loop) |
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{ |
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struct sk_buff *newskb = NULL; |
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struct canfd_frame *cfd = (struct canfd_frame *)skb->data; |
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struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats; |
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int err = -EINVAL; |
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|
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if (skb->len == CAN_MTU) { |
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skb->protocol = htons(ETH_P_CAN); |
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if (unlikely(cfd->len > CAN_MAX_DLEN)) |
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goto inval_skb; |
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} else if (skb->len == CANFD_MTU) { |
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skb->protocol = htons(ETH_P_CANFD); |
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if (unlikely(cfd->len > CANFD_MAX_DLEN)) |
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goto inval_skb; |
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} else { |
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goto inval_skb; |
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} |
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|
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/* Make sure the CAN frame can pass the selected CAN netdevice. |
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* As structs can_frame and canfd_frame are similar, we can provide |
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* CAN FD frames to legacy CAN drivers as long as the length is <= 8 |
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*/ |
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if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) { |
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err = -EMSGSIZE; |
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goto inval_skb; |
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} |
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if (unlikely(skb->dev->type != ARPHRD_CAN)) { |
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err = -EPERM; |
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goto inval_skb; |
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} |
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if (unlikely(!(skb->dev->flags & IFF_UP))) { |
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err = -ENETDOWN; |
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goto inval_skb; |
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} |
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skb->ip_summed = CHECKSUM_UNNECESSARY; |
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skb_reset_mac_header(skb); |
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skb_reset_network_header(skb); |
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skb_reset_transport_header(skb); |
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if (loop) { |
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/* local loopback of sent CAN frames */ |
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|
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/* indication for the CAN driver: do loopback */ |
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skb->pkt_type = PACKET_LOOPBACK; |
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|
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/* The reference to the originating sock may be required |
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* by the receiving socket to check whether the frame is |
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* its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS |
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* Therefore we have to ensure that skb->sk remains the |
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* reference to the originating sock by restoring skb->sk |
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* after each skb_clone() or skb_orphan() usage. |
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*/ |
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if (!(skb->dev->flags & IFF_ECHO)) { |
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/* If the interface is not capable to do loopback |
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* itself, we do it here. |
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*/ |
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newskb = skb_clone(skb, GFP_ATOMIC); |
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if (!newskb) { |
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kfree_skb(skb); |
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return -ENOMEM; |
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} |
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can_skb_set_owner(newskb, skb->sk); |
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newskb->ip_summed = CHECKSUM_UNNECESSARY; |
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newskb->pkt_type = PACKET_BROADCAST; |
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} |
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} else { |
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/* indication for the CAN driver: no loopback required */ |
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skb->pkt_type = PACKET_HOST; |
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} |
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/* send to netdevice */ |
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err = dev_queue_xmit(skb); |
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if (err > 0) |
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err = net_xmit_errno(err); |
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if (err) { |
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kfree_skb(newskb); |
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return err; |
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} |
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if (newskb) |
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netif_rx_ni(newskb); |
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/* update statistics */ |
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pkg_stats->tx_frames++; |
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pkg_stats->tx_frames_delta++; |
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return 0; |
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inval_skb: |
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kfree_skb(skb); |
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return err; |
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} |
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EXPORT_SYMBOL(can_send); |
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/* af_can rx path */ |
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static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net, |
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struct net_device *dev) |
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{ |
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if (dev) { |
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struct can_ml_priv *can_ml = can_get_ml_priv(dev); |
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return &can_ml->dev_rcv_lists; |
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} else { |
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return net->can.rx_alldev_list; |
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} |
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} |
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/** |
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* effhash - hash function for 29 bit CAN identifier reduction |
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* @can_id: 29 bit CAN identifier |
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* |
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* Description: |
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* To reduce the linear traversal in one linked list of _single_ EFF CAN |
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* frame subscriptions the 29 bit identifier is mapped to 10 bits. |
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* (see CAN_EFF_RCV_HASH_BITS definition) |
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* |
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* Return: |
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* Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask ) |
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*/ |
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static unsigned int effhash(canid_t can_id) |
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{ |
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unsigned int hash; |
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|
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hash = can_id; |
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hash ^= can_id >> CAN_EFF_RCV_HASH_BITS; |
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hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS); |
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|
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return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1); |
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} |
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/** |
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* can_rcv_list_find - determine optimal filterlist inside device filter struct |
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* @can_id: pointer to CAN identifier of a given can_filter |
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* @mask: pointer to CAN mask of a given can_filter |
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* @dev_rcv_lists: pointer to the device filter struct |
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* |
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* Description: |
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* Returns the optimal filterlist to reduce the filter handling in the |
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* receive path. This function is called by service functions that need |
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* to register or unregister a can_filter in the filter lists. |
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* |
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* A filter matches in general, when |
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* |
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* <received_can_id> & mask == can_id & mask |
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* |
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* so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe |
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* relevant bits for the filter. |
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* |
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* The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can |
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* filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg |
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* frames there is a special filterlist and a special rx path filter handling. |
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* |
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* Return: |
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* Pointer to optimal filterlist for the given can_id/mask pair. |
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* Consistency checked mask. |
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* Reduced can_id to have a preprocessed filter compare value. |
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*/ |
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static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask, |
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struct can_dev_rcv_lists *dev_rcv_lists) |
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{ |
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canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ |
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|
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/* filter for error message frames in extra filterlist */ |
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if (*mask & CAN_ERR_FLAG) { |
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/* clear CAN_ERR_FLAG in filter entry */ |
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*mask &= CAN_ERR_MASK; |
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return &dev_rcv_lists->rx[RX_ERR]; |
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} |
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|
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/* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
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|
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#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) |
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|
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/* ensure valid values in can_mask for 'SFF only' frame filtering */ |
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if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) |
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*mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); |
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|
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/* reduce condition testing at receive time */ |
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*can_id &= *mask; |
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|
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/* inverse can_id/can_mask filter */ |
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if (inv) |
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return &dev_rcv_lists->rx[RX_INV]; |
|
|
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/* mask == 0 => no condition testing at receive time */ |
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if (!(*mask)) |
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return &dev_rcv_lists->rx[RX_ALL]; |
|
|
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/* extra filterlists for the subscription of a single non-RTR can_id */ |
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if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) && |
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!(*can_id & CAN_RTR_FLAG)) { |
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if (*can_id & CAN_EFF_FLAG) { |
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if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) |
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return &dev_rcv_lists->rx_eff[effhash(*can_id)]; |
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} else { |
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if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) |
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return &dev_rcv_lists->rx_sff[*can_id]; |
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} |
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} |
|
|
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/* default: filter via can_id/can_mask */ |
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return &dev_rcv_lists->rx[RX_FIL]; |
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} |
|
|
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/** |
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* can_rx_register - subscribe CAN frames from a specific interface |
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* @net: the applicable net namespace |
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* @dev: pointer to netdevice (NULL => subscribe from 'all' CAN devices list) |
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* @can_id: CAN identifier (see description) |
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* @mask: CAN mask (see description) |
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* @func: callback function on filter match |
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* @data: returned parameter for callback function |
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* @ident: string for calling module identification |
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* @sk: socket pointer (might be NULL) |
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* |
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* Description: |
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* Invokes the callback function with the received sk_buff and the given |
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* parameter 'data' on a matching receive filter. A filter matches, when |
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* |
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* <received_can_id> & mask == can_id & mask |
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* |
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* The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can |
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* filter for error message frames (CAN_ERR_FLAG bit set in mask). |
|
* |
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* The provided pointer to the sk_buff is guaranteed to be valid as long as |
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* the callback function is running. The callback function must *not* free |
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* the given sk_buff while processing it's task. When the given sk_buff is |
|
* needed after the end of the callback function it must be cloned inside |
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* the callback function with skb_clone(). |
|
* |
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* Return: |
|
* 0 on success |
|
* -ENOMEM on missing cache mem to create subscription entry |
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* -ENODEV unknown device |
|
*/ |
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int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, |
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canid_t mask, void (*func)(struct sk_buff *, void *), |
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void *data, char *ident, struct sock *sk) |
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{ |
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struct receiver *rcv; |
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struct hlist_head *rcv_list; |
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struct can_dev_rcv_lists *dev_rcv_lists; |
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struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; |
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int err = 0; |
|
|
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/* insert new receiver (dev,canid,mask) -> (func,data) */ |
|
|
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if (dev && dev->type != ARPHRD_CAN) |
|
return -ENODEV; |
|
|
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if (dev && !net_eq(net, dev_net(dev))) |
|
return -ENODEV; |
|
|
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rcv = kmem_cache_alloc(rcv_cache, GFP_KERNEL); |
|
if (!rcv) |
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return -ENOMEM; |
|
|
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spin_lock_bh(&net->can.rcvlists_lock); |
|
|
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dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
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rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists); |
|
|
|
rcv->can_id = can_id; |
|
rcv->mask = mask; |
|
rcv->matches = 0; |
|
rcv->func = func; |
|
rcv->data = data; |
|
rcv->ident = ident; |
|
rcv->sk = sk; |
|
|
|
hlist_add_head_rcu(&rcv->list, rcv_list); |
|
dev_rcv_lists->entries++; |
|
|
|
rcv_lists_stats->rcv_entries++; |
|
rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max, |
|
rcv_lists_stats->rcv_entries); |
|
spin_unlock_bh(&net->can.rcvlists_lock); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL(can_rx_register); |
|
|
|
/* can_rx_delete_receiver - rcu callback for single receiver entry removal */ |
|
static void can_rx_delete_receiver(struct rcu_head *rp) |
|
{ |
|
struct receiver *rcv = container_of(rp, struct receiver, rcu); |
|
struct sock *sk = rcv->sk; |
|
|
|
kmem_cache_free(rcv_cache, rcv); |
|
if (sk) |
|
sock_put(sk); |
|
} |
|
|
|
/** |
|
* can_rx_unregister - unsubscribe CAN frames from a specific interface |
|
* @net: the applicable net namespace |
|
* @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list) |
|
* @can_id: CAN identifier |
|
* @mask: CAN mask |
|
* @func: callback function on filter match |
|
* @data: returned parameter for callback function |
|
* |
|
* Description: |
|
* Removes subscription entry depending on given (subscription) values. |
|
*/ |
|
void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id, |
|
canid_t mask, void (*func)(struct sk_buff *, void *), |
|
void *data) |
|
{ |
|
struct receiver *rcv = NULL; |
|
struct hlist_head *rcv_list; |
|
struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; |
|
struct can_dev_rcv_lists *dev_rcv_lists; |
|
|
|
if (dev && dev->type != ARPHRD_CAN) |
|
return; |
|
|
|
if (dev && !net_eq(net, dev_net(dev))) |
|
return; |
|
|
|
spin_lock_bh(&net->can.rcvlists_lock); |
|
|
|
dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
|
rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists); |
|
|
|
/* Search the receiver list for the item to delete. This should |
|
* exist, since no receiver may be unregistered that hasn't |
|
* been registered before. |
|
*/ |
|
hlist_for_each_entry_rcu(rcv, rcv_list, list) { |
|
if (rcv->can_id == can_id && rcv->mask == mask && |
|
rcv->func == func && rcv->data == data) |
|
break; |
|
} |
|
|
|
/* Check for bugs in CAN protocol implementations using af_can.c: |
|
* 'rcv' will be NULL if no matching list item was found for removal. |
|
* As this case may potentially happen when closing a socket while |
|
* the notifier for removing the CAN netdev is running we just print |
|
* a warning here. |
|
*/ |
|
if (!rcv) { |
|
pr_warn("can: receive list entry not found for dev %s, id %03X, mask %03X\n", |
|
DNAME(dev), can_id, mask); |
|
goto out; |
|
} |
|
|
|
hlist_del_rcu(&rcv->list); |
|
dev_rcv_lists->entries--; |
|
|
|
if (rcv_lists_stats->rcv_entries > 0) |
|
rcv_lists_stats->rcv_entries--; |
|
|
|
out: |
|
spin_unlock_bh(&net->can.rcvlists_lock); |
|
|
|
/* schedule the receiver item for deletion */ |
|
if (rcv) { |
|
if (rcv->sk) |
|
sock_hold(rcv->sk); |
|
call_rcu(&rcv->rcu, can_rx_delete_receiver); |
|
} |
|
} |
|
EXPORT_SYMBOL(can_rx_unregister); |
|
|
|
static inline void deliver(struct sk_buff *skb, struct receiver *rcv) |
|
{ |
|
rcv->func(skb, rcv->data); |
|
rcv->matches++; |
|
} |
|
|
|
static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb) |
|
{ |
|
struct receiver *rcv; |
|
int matches = 0; |
|
struct can_frame *cf = (struct can_frame *)skb->data; |
|
canid_t can_id = cf->can_id; |
|
|
|
if (dev_rcv_lists->entries == 0) |
|
return 0; |
|
|
|
if (can_id & CAN_ERR_FLAG) { |
|
/* check for error message frame entries only */ |
|
hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) { |
|
if (can_id & rcv->mask) { |
|
deliver(skb, rcv); |
|
matches++; |
|
} |
|
} |
|
return matches; |
|
} |
|
|
|
/* check for unfiltered entries */ |
|
hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) { |
|
deliver(skb, rcv); |
|
matches++; |
|
} |
|
|
|
/* check for can_id/mask entries */ |
|
hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) { |
|
if ((can_id & rcv->mask) == rcv->can_id) { |
|
deliver(skb, rcv); |
|
matches++; |
|
} |
|
} |
|
|
|
/* check for inverted can_id/mask entries */ |
|
hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) { |
|
if ((can_id & rcv->mask) != rcv->can_id) { |
|
deliver(skb, rcv); |
|
matches++; |
|
} |
|
} |
|
|
|
/* check filterlists for single non-RTR can_ids */ |
|
if (can_id & CAN_RTR_FLAG) |
|
return matches; |
|
|
|
if (can_id & CAN_EFF_FLAG) { |
|
hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) { |
|
if (rcv->can_id == can_id) { |
|
deliver(skb, rcv); |
|
matches++; |
|
} |
|
} |
|
} else { |
|
can_id &= CAN_SFF_MASK; |
|
hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) { |
|
deliver(skb, rcv); |
|
matches++; |
|
} |
|
} |
|
|
|
return matches; |
|
} |
|
|
|
static void can_receive(struct sk_buff *skb, struct net_device *dev) |
|
{ |
|
struct can_dev_rcv_lists *dev_rcv_lists; |
|
struct net *net = dev_net(dev); |
|
struct can_pkg_stats *pkg_stats = net->can.pkg_stats; |
|
int matches; |
|
|
|
/* update statistics */ |
|
pkg_stats->rx_frames++; |
|
pkg_stats->rx_frames_delta++; |
|
|
|
/* create non-zero unique skb identifier together with *skb */ |
|
while (!(can_skb_prv(skb)->skbcnt)) |
|
can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter); |
|
|
|
rcu_read_lock(); |
|
|
|
/* deliver the packet to sockets listening on all devices */ |
|
matches = can_rcv_filter(net->can.rx_alldev_list, skb); |
|
|
|
/* find receive list for this device */ |
|
dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
|
matches += can_rcv_filter(dev_rcv_lists, skb); |
|
|
|
rcu_read_unlock(); |
|
|
|
/* consume the skbuff allocated by the netdevice driver */ |
|
consume_skb(skb); |
|
|
|
if (matches > 0) { |
|
pkg_stats->matches++; |
|
pkg_stats->matches_delta++; |
|
} |
|
} |
|
|
|
static int can_rcv(struct sk_buff *skb, struct net_device *dev, |
|
struct packet_type *pt, struct net_device *orig_dev) |
|
{ |
|
struct canfd_frame *cfd = (struct canfd_frame *)skb->data; |
|
|
|
if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) { |
|
pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n", |
|
dev->type, skb->len); |
|
goto free_skb; |
|
} |
|
|
|
/* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */ |
|
if (unlikely(cfd->len > CAN_MAX_DLEN)) { |
|
pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d, datalen %d\n", |
|
dev->type, skb->len, cfd->len); |
|
goto free_skb; |
|
} |
|
|
|
can_receive(skb, dev); |
|
return NET_RX_SUCCESS; |
|
|
|
free_skb: |
|
kfree_skb(skb); |
|
return NET_RX_DROP; |
|
} |
|
|
|
static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, |
|
struct packet_type *pt, struct net_device *orig_dev) |
|
{ |
|
struct canfd_frame *cfd = (struct canfd_frame *)skb->data; |
|
|
|
if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) { |
|
pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n", |
|
dev->type, skb->len); |
|
goto free_skb; |
|
} |
|
|
|
/* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */ |
|
if (unlikely(cfd->len > CANFD_MAX_DLEN)) { |
|
pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d, datalen %d\n", |
|
dev->type, skb->len, cfd->len); |
|
goto free_skb; |
|
} |
|
|
|
can_receive(skb, dev); |
|
return NET_RX_SUCCESS; |
|
|
|
free_skb: |
|
kfree_skb(skb); |
|
return NET_RX_DROP; |
|
} |
|
|
|
/* af_can protocol functions */ |
|
|
|
/** |
|
* can_proto_register - register CAN transport protocol |
|
* @cp: pointer to CAN protocol structure |
|
* |
|
* Return: |
|
* 0 on success |
|
* -EINVAL invalid (out of range) protocol number |
|
* -EBUSY protocol already in use |
|
* -ENOBUF if proto_register() fails |
|
*/ |
|
int can_proto_register(const struct can_proto *cp) |
|
{ |
|
int proto = cp->protocol; |
|
int err = 0; |
|
|
|
if (proto < 0 || proto >= CAN_NPROTO) { |
|
pr_err("can: protocol number %d out of range\n", proto); |
|
return -EINVAL; |
|
} |
|
|
|
err = proto_register(cp->prot, 0); |
|
if (err < 0) |
|
return err; |
|
|
|
mutex_lock(&proto_tab_lock); |
|
|
|
if (rcu_access_pointer(proto_tab[proto])) { |
|
pr_err("can: protocol %d already registered\n", proto); |
|
err = -EBUSY; |
|
} else { |
|
RCU_INIT_POINTER(proto_tab[proto], cp); |
|
} |
|
|
|
mutex_unlock(&proto_tab_lock); |
|
|
|
if (err < 0) |
|
proto_unregister(cp->prot); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL(can_proto_register); |
|
|
|
/** |
|
* can_proto_unregister - unregister CAN transport protocol |
|
* @cp: pointer to CAN protocol structure |
|
*/ |
|
void can_proto_unregister(const struct can_proto *cp) |
|
{ |
|
int proto = cp->protocol; |
|
|
|
mutex_lock(&proto_tab_lock); |
|
BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp); |
|
RCU_INIT_POINTER(proto_tab[proto], NULL); |
|
mutex_unlock(&proto_tab_lock); |
|
|
|
synchronize_rcu(); |
|
|
|
proto_unregister(cp->prot); |
|
} |
|
EXPORT_SYMBOL(can_proto_unregister); |
|
|
|
static int can_pernet_init(struct net *net) |
|
{ |
|
spin_lock_init(&net->can.rcvlists_lock); |
|
net->can.rx_alldev_list = |
|
kzalloc(sizeof(*net->can.rx_alldev_list), GFP_KERNEL); |
|
if (!net->can.rx_alldev_list) |
|
goto out; |
|
net->can.pkg_stats = kzalloc(sizeof(*net->can.pkg_stats), GFP_KERNEL); |
|
if (!net->can.pkg_stats) |
|
goto out_free_rx_alldev_list; |
|
net->can.rcv_lists_stats = kzalloc(sizeof(*net->can.rcv_lists_stats), GFP_KERNEL); |
|
if (!net->can.rcv_lists_stats) |
|
goto out_free_pkg_stats; |
|
|
|
if (IS_ENABLED(CONFIG_PROC_FS)) { |
|
/* the statistics are updated every second (timer triggered) */ |
|
if (stats_timer) { |
|
timer_setup(&net->can.stattimer, can_stat_update, |
|
0); |
|
mod_timer(&net->can.stattimer, |
|
round_jiffies(jiffies + HZ)); |
|
} |
|
net->can.pkg_stats->jiffies_init = jiffies; |
|
can_init_proc(net); |
|
} |
|
|
|
return 0; |
|
|
|
out_free_pkg_stats: |
|
kfree(net->can.pkg_stats); |
|
out_free_rx_alldev_list: |
|
kfree(net->can.rx_alldev_list); |
|
out: |
|
return -ENOMEM; |
|
} |
|
|
|
static void can_pernet_exit(struct net *net) |
|
{ |
|
if (IS_ENABLED(CONFIG_PROC_FS)) { |
|
can_remove_proc(net); |
|
if (stats_timer) |
|
del_timer_sync(&net->can.stattimer); |
|
} |
|
|
|
kfree(net->can.rx_alldev_list); |
|
kfree(net->can.pkg_stats); |
|
kfree(net->can.rcv_lists_stats); |
|
} |
|
|
|
/* af_can module init/exit functions */ |
|
|
|
static struct packet_type can_packet __read_mostly = { |
|
.type = cpu_to_be16(ETH_P_CAN), |
|
.func = can_rcv, |
|
}; |
|
|
|
static struct packet_type canfd_packet __read_mostly = { |
|
.type = cpu_to_be16(ETH_P_CANFD), |
|
.func = canfd_rcv, |
|
}; |
|
|
|
static const struct net_proto_family can_family_ops = { |
|
.family = PF_CAN, |
|
.create = can_create, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
static struct pernet_operations can_pernet_ops __read_mostly = { |
|
.init = can_pernet_init, |
|
.exit = can_pernet_exit, |
|
}; |
|
|
|
static __init int can_init(void) |
|
{ |
|
int err; |
|
|
|
/* check for correct padding to be able to use the structs similarly */ |
|
BUILD_BUG_ON(offsetof(struct can_frame, len) != |
|
offsetof(struct canfd_frame, len) || |
|
offsetof(struct can_frame, data) != |
|
offsetof(struct canfd_frame, data)); |
|
|
|
pr_info("can: controller area network core\n"); |
|
|
|
rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), |
|
0, 0, NULL); |
|
if (!rcv_cache) |
|
return -ENOMEM; |
|
|
|
err = register_pernet_subsys(&can_pernet_ops); |
|
if (err) |
|
goto out_pernet; |
|
|
|
/* protocol register */ |
|
err = sock_register(&can_family_ops); |
|
if (err) |
|
goto out_sock; |
|
|
|
dev_add_pack(&can_packet); |
|
dev_add_pack(&canfd_packet); |
|
|
|
return 0; |
|
|
|
out_sock: |
|
unregister_pernet_subsys(&can_pernet_ops); |
|
out_pernet: |
|
kmem_cache_destroy(rcv_cache); |
|
|
|
return err; |
|
} |
|
|
|
static __exit void can_exit(void) |
|
{ |
|
/* protocol unregister */ |
|
dev_remove_pack(&canfd_packet); |
|
dev_remove_pack(&can_packet); |
|
sock_unregister(PF_CAN); |
|
|
|
unregister_pernet_subsys(&can_pernet_ops); |
|
|
|
rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
|
|
|
kmem_cache_destroy(rcv_cache); |
|
} |
|
|
|
module_init(can_init); |
|
module_exit(can_exit);
|
|
|