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Release 4.11 drivers/net/can/vcan.c

Directory: drivers/net/can
/*
 * vcan.c - Virtual CAN interface
 *
 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Volkswagen nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Alternatively, provided that this notice is retained in full, this
 * software may be distributed under the terms of the GNU General
 * Public License ("GPL") version 2, in which case the provisions of the
 * GPL apply INSTEAD OF those given above.
 *
 * The provided data structures and external interfaces from this code
 * are not restricted to be used by modules with a GPL compatible license.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/skb.h>
#include <linux/slab.h>
#include <net/rtnetlink.h>

MODULE_DESCRIPTION("virtual CAN interface");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");


/*
 * CAN test feature:
 * Enable the echo on driver level for testing the CAN core echo modes.
 * See Documentation/networking/can.txt for details.
 */


static bool echo; 
/* echo testing. Default: 0 (Off) */
module_param(echo, bool, S_IRUGO);
MODULE_PARM_DESC(echo, "Echo sent frames (for testing). Default: 0 (Off)");



static void vcan_rx(struct sk_buff *skb, struct net_device *dev) { struct canfd_frame *cfd = (struct canfd_frame *)skb->data; struct net_device_stats *stats = &dev->stats; stats->rx_packets++; stats->rx_bytes += cfd->len; skb->pkt_type = PACKET_BROADCAST; skb->dev = dev; skb->ip_summed = CHECKSUM_UNNECESSARY; netif_rx_ni(skb); }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Hartkopp76100.00%4100.00%
Total76100.00%4100.00%


static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev) { struct canfd_frame *cfd = (struct canfd_frame *)skb->data; struct net_device_stats *stats = &dev->stats; int loop; if (can_dropped_invalid_skb(dev, skb)) return NETDEV_TX_OK; stats->tx_packets++; stats->tx_bytes += cfd->len; /* set flag whether this packet has to be looped back */ loop = skb->pkt_type == PACKET_LOOPBACK; if (!echo) { /* no echo handling available inside this driver */ if (loop) { /* * only count the packets here, because the * CAN core already did the echo for us */ stats->rx_packets++; stats->rx_bytes += cfd->len; } consume_skb(skb); return NETDEV_TX_OK; } /* perform standard echo handling for CAN network interfaces */ if (loop) { skb = can_create_echo_skb(skb); if (!skb) return NETDEV_TX_OK; /* receive with packet counting */ vcan_rx(skb, dev); } else { /* no looped packets => no counting */ consume_skb(skb); } return NETDEV_TX_OK; }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Hartkopp15499.35%480.00%
Stephen Hemminger10.65%120.00%
Total155100.00%5100.00%


static int vcan_change_mtu(struct net_device *dev, int new_mtu) { /* Do not allow changing the MTU while running */ if (dev->flags & IFF_UP) return -EBUSY; if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU) return -EINVAL; dev->mtu = new_mtu; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Hartkopp50100.00%1100.00%
Total50100.00%1100.00%

static const struct net_device_ops vcan_netdev_ops = { .ndo_start_xmit = vcan_tx, .ndo_change_mtu = vcan_change_mtu, };
static void vcan_setup(struct net_device *dev) { dev->type = ARPHRD_CAN; dev->mtu = CAN_MTU; dev->hard_header_len = 0; dev->addr_len = 0; dev->tx_queue_len = 0; dev->flags = IFF_NOARP; /* set flags according to driver capabilities */ if (echo) dev->flags |= IFF_ECHO; dev->netdev_ops = &vcan_netdev_ops; dev->destructor = free_netdev; }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Hartkopp71100.00%3100.00%
Total71100.00%3100.00%

static struct rtnl_link_ops vcan_link_ops __read_mostly = { .kind = "vcan", .setup = vcan_setup, };
static __init int vcan_init_module(void) { pr_info("vcan: Virtual CAN interface driver\n"); if (echo) printk(KERN_INFO "vcan: enabled echo on driver level.\n"); return rtnl_link_register(&vcan_link_ops); }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Hartkopp2993.55%150.00%
Jeremiah Mahler26.45%150.00%
Total31100.00%2100.00%


static __exit void vcan_cleanup_module(void) { rtnl_link_unregister(&vcan_link_ops); }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Hartkopp15100.00%1100.00%
Total15100.00%1100.00%

module_init(vcan_init_module); module_exit(vcan_cleanup_module);

Overall Contributors

PersonTokensPropCommitsCommitProp
Oliver Hartkopp50498.44%654.55%
Tejun Heo30.59%19.09%
Jeremiah Mahler20.39%19.09%
Stephen Hemminger10.20%19.09%
Rusty Russell10.20%19.09%
Marc Kleine-Budde10.20%19.09%
Total512100.00%11100.00%
Directory: drivers/net/can
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