path: root/net/can/bcm.c

/*
 * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
 *
 * 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.
 *
 * Send feedback to <socketcan-users@lists.berlios.de>
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/hrtimer.h>
#include <linux/list.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/uio.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/socket.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/can.h>
#include <linux/can/core.h>
#include <linux/can/bcm.h>
#include <net/sock.h>
#include <net/net_namespace.h>

/* use of last_frames[index].can_dlc */
#define RX_RECV    0x40 /* received data for this element */
#define RX_THR     0x80 /* element not been sent due to throttle feature */
#define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */

/* get best masking value for can_rx_register() for a given single can_id */
#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
		     (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
		     (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))

#define CAN_BCM_VERSION CAN_VERSION
static __initdata const char banner[] = KERN_INFO
	"can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";

MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
MODULE_ALIAS("can-proto-2");

/* easy access to can_frame payload */
static inline u64 GET_U64(const struct can_frame *cp)
{
	return *(u64 *)cp->data;
}

struct bcm_op {
	struct list_head list;
	int ifindex;
	canid_t can_id;
	int flags;
	unsigned long frames_abs, frames_filtered;
	struct timeval ival1, ival2;
	struct hrtimer timer, thrtimer;
	struct tasklet_struct tsklet, thrtsklet;
	ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
	int rx_ifindex;
	int count;
	int nframes;
	int currframe;
	struct can_frame *frames;
	struct can_frame *last_frames;
	struct can_frame sframe;
	struct can_frame last_sframe;
	struct sock *sk;
	struct net_device *rx_reg_dev;
};

static struct proc_dir_entry *proc_dir;

struct bcm_sock {
	struct sock sk;
	int bound;
	int ifindex;
	struct notifier_block notifier;
	struct list_head rx_ops;
	struct list_head tx_ops;
	unsigned long dropped_usr_msgs;
	struct proc_dir_entry *bcm_proc_read;
	char procname [9]; /* pointer printed in ASCII with \0 */
};

static inline struct bcm_sock *bcm_sk(const struct sock *sk)
{
	return (struct bcm_sock *)sk;
}

#define CFSIZ sizeof(struct can_frame)
#define OPSIZ sizeof(struct bcm_op)
#define MHSIZ sizeof(struct bcm_msg_head)

/*
 * procfs functions
 */
static char *bcm_proc_getifname(int ifindex)
{
	struct net_device