Initial import

1 files changed, 190 insertions, 0 deletions

diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c
new file mode 100644
index 000000000..0ce868de8
--- /dev/null
+++ b/drivers/net/can/vcan.c
@@ -0,0 +1,190 @@
+/*
+ * 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;
+
+	if (!(skb->tstamp.tv64))
+		__net_timestamp(skb);
+
+	netif_rx_ni(skb);
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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);
+}
+
+static __exit void vcan_cleanup_module(void)
+{
+	rtnl_link_unregister(&vcan_link_ops);
+}
+
+module_init(vcan_init_module);
+module_exit(vcan_cleanup_module);