This patch adds the virtual CAN bus (vcan) network driver. The vcan device is just a loopback device for CAN frames, no real CAN hardware is involved. Signed-off-by: Oliver Hartkopp Signed-off-by: Urs Thuermann --- drivers/net/Makefile | 1 drivers/net/can/Kconfig | 25 ++++ drivers/net/can/Makefile | 5 drivers/net/can/vcan.c | 260 +++++++++++++++++++++++++++++++++++++++++++++++ net/can/Kconfig | 3 5 files changed, 294 insertions(+) Index: net-2.6.24/drivers/net/Makefile =================================================================== --- net-2.6.24.orig/drivers/net/Makefile 2007-09-17 10:30:35.000000000 +0200 +++ net-2.6.24/drivers/net/Makefile 2007-09-17 11:13:45.000000000 +0200 @@ -10,6 +10,7 @@ obj-$(CONFIG_CHELSIO_T1) += chelsio/ obj-$(CONFIG_CHELSIO_T3) += cxgb3/ obj-$(CONFIG_EHEA) += ehea/ +obj-$(CONFIG_CAN) += can/ obj-$(CONFIG_BONDING) += bonding/ obj-$(CONFIG_ATL1) += atl1/ obj-$(CONFIG_GIANFAR) += gianfar_driver.o Index: net-2.6.24/drivers/net/can/Kconfig =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ net-2.6.24/drivers/net/can/Kconfig 2007-09-17 11:13:45.000000000 +0200 @@ -0,0 +1,25 @@ +menu "CAN Device Drivers" + depends on CAN + +config CAN_VCAN + tristate "Virtual Local CAN Interface (vcan)" + depends on CAN + default N + ---help--- + Similar to the network loopback devices, vcan offers a + virtual local CAN interface. + + This driver can also be built as a module. If so, the module + will be called vcan. + +config CAN_DEBUG_DEVICES + bool "CAN devices debugging messages" + depends on CAN + default N + ---help--- + Say Y here if you want the CAN device drivers to produce a bunch of + debug messages to the system log. Select this if you are having + a problem with CAN support and want to see more of what is going + on. + +endmenu Index: net-2.6.24/drivers/net/can/Makefile =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ net-2.6.24/drivers/net/can/Makefile 2007-09-17 11:13:45.000000000 +0200 @@ -0,0 +1,5 @@ +# +# Makefile for the Linux Controller Area Network drivers. +# + +obj-$(CONFIG_CAN_VCAN) += vcan.o Index: net-2.6.24/drivers/net/can/vcan.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ net-2.6.24/drivers/net/can/vcan.c 2007-09-17 11:17:45.000000000 +0200 @@ -0,0 +1,260 @@ +/* + * 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, the following disclaimer and + * the referenced file 'COPYING'. + * 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 as distributed in the 'COPYING' + * file from the main directory of the linux kernel source. + * + * 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. + * + * Send feedback to + * + */ + +#include +#include +#include +#include +#include +#include +#include + +static __initdata const char banner[] = + KERN_INFO "vcan: Virtual CAN interface driver\n"; + +MODULE_DESCRIPTION("virtual CAN interface"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Urs Thuermann "); + +#ifdef CONFIG_CAN_DEBUG_DEVICES +static int debug; +module_param(debug, int, S_IRUGO); +#endif + +/* To be moved to linux/can/dev.h */ +#ifdef CONFIG_CAN_DEBUG_DEVICES +#define DBG(args...) (debug & 1 ? \ + (printk(KERN_DEBUG "vcan %s: ", __func__), \ + printk(args)) : 0) +#else +#define DBG(args...) +#endif + + +/* + * CAN test feature: + * Enable the loopback on driver level for testing the CAN core loopback modes. + * See Documentation/networking/can.txt for details. + */ + +static int loopback; /* loopback testing. Default: 0 (Off) */ +module_param(loopback, int, S_IRUGO); +MODULE_PARM_DESC(loopback, "Loop back frames (for testing). Default: 0 (Off)"); + +struct vcan_priv { + struct net_device *dev; + struct list_head list; +}; +static LIST_HEAD(vcan_devs); + +static int vcan_open(struct net_device *dev) +{ + DBG("%s: interface up\n", dev->name); + + netif_start_queue(dev); + return 0; +} + +static int vcan_stop(struct net_device *dev) +{ + DBG("%s: interface down\n", dev->name); + + netif_stop_queue(dev); + return 0; +} + +static void vcan_rx(struct sk_buff *skb, struct net_device *dev) +{ + struct net_device_stats *stats = &dev->stats; + + stats->rx_packets++; + stats->rx_bytes += skb->len; + + skb->protocol = htons(ETH_P_CAN); + skb->pkt_type = PACKET_BROADCAST; + skb->dev = dev; + skb->ip_summed = CHECKSUM_UNNECESSARY; + + DBG("received skbuff on interface %d\n", dev->ifindex); + + netif_rx(skb); +} + +static int vcan_tx(struct sk_buff *skb, struct net_device *dev) +{ + struct net_device_stats *stats = &dev->stats; + int loop; + + DBG("sending skbuff on interface %s\n", dev->name); + + stats->tx_packets++; + stats->tx_bytes += skb->len; + + /* set flag whether this packet has to be looped back */ + loop = skb->pkt_type == PACKET_LOOPBACK; + + if (!loopback) { + /* no loopback handling available inside this driver */ + + if (loop) { + /* + * only count the packets here, because the + * CAN core already did the loopback for us + */ + stats->rx_packets++; + stats->rx_bytes += skb->len; + } + kfree_skb(skb); + return 0; + } + + /* perform standard loopback handling for CAN network interfaces */ + + if (loop) { + struct sock *srcsk = skb->sk; + + if (atomic_read(&skb->users) != 1) { + struct sk_buff *old_skb = skb; + + skb = skb_clone(old_skb, GFP_ATOMIC); + DBG(KERN_INFO "%s: %s: freeing old skbuff %p, " + "using new skbuff %p\n", + dev->name, __FUNCTION__, old_skb, skb); + kfree_skb(old_skb); + if (!skb) + return 0; + } else + skb_orphan(skb); + + /* receive with packet counting */ + skb->sk = srcsk; + vcan_rx(skb, dev); + } else { + /* no looped packets => no counting */ + kfree_skb(skb); + } + return 0; +} + +static void vcan_setup(struct net_device *dev) +{ + DBG("dev %s\n", dev->name); + + dev->type = ARPHRD_CAN; + dev->mtu = sizeof(struct can_frame); + 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 (loopback) + dev->flags |= IFF_LOOPBACK; + + dev->open = vcan_open; + dev->stop = vcan_stop; + dev->hard_start_xmit = vcan_tx; + dev->destructor = free_netdev; + +} + +static int vcan_newlink(struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[]) +{ + struct vcan_priv *priv = netdev_priv(dev); + int err; + + err = register_netdevice(dev); + if (err < 0) + return err; + + priv->dev = dev; + list_add_tail(&priv->list, &vcan_devs); + return 0; +} + +static void vcan_dellink(struct net_device *dev) +{ + struct vcan_priv *priv = netdev_priv(dev); + + list_del(&priv->list); + unregister_netdevice(dev); +} + +static struct rtnl_link_ops vcan_link_ops __read_mostly = { + .kind = "vcan", + .priv_size = sizeof(struct vcan_priv), + .setup = vcan_setup, + .newlink = vcan_newlink, + .dellink = vcan_dellink, +}; + +static __init int vcan_init_module(void) +{ + int err; + + printk(banner); + + if (loopback) + printk(KERN_INFO "vcan: enabled loopback on driver level.\n"); + + rtnl_lock(); + err = __rtnl_link_register(&vcan_link_ops); + rtnl_unlock(); + return err; +} + +static __exit void vcan_cleanup_module(void) +{ + struct vcan_priv *priv, *n; + + rtnl_lock(); + list_for_each_entry_safe(priv, n, &vcan_devs, list) + vcan_dellink(priv->dev); + __rtnl_link_unregister(&vcan_link_ops); + rtnl_unlock(); +} + +module_init(vcan_init_module); +module_exit(vcan_cleanup_module); Index: net-2.6.24/net/can/Kconfig =================================================================== --- net-2.6.24.orig/net/can/Kconfig 2007-09-17 11:12:30.000000000 +0200 +++ net-2.6.24/net/can/Kconfig 2007-09-17 11:13:45.000000000 +0200 @@ -77,3 +77,6 @@ Say Y here if you want the CAN core to produce a bunch of debug messages to the system log. Select this if you are having a problem with CAN support and want to see more of what is going on. + + +source "drivers/net/can/Kconfig" -- - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html