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Commit c18ce101 authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by David S. Miller
Browse files

[CAN]: Add raw protocol 



This patch adds the CAN raw protocol.

Signed-off-by: default avatarOliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: default avatarUrs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0d66548a

include/linux/can/raw.h

0 → 100644
+31 −0
Original line number Diff line number Diff line 
/*

 * linux/can/raw.h

 *

 * Definitions for raw CAN sockets

 *

 * Authors: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>

 *          Urs Thuermann   <urs.thuermann@volkswagen.de>

 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research

 * All rights reserved.

 *

 * Send feedback to <socketcan-users@lists.berlios.de>

 *

 */



#ifndef CAN_RAW_H

#define CAN_RAW_H



#include <linux/can.h>



#define SOL_CAN_RAW (SOL_CAN_BASE + CAN_RAW)



/* for socket options affecting the socket (not the global system) */



enum {

	CAN_RAW_FILTER = 1,	/* set 0 .. n can_filter(s)          */

	CAN_RAW_ERR_FILTER,	/* set filter for error frames       */

	CAN_RAW_LOOPBACK,	/* local loopback (default:on)       */

	CAN_RAW_RECV_OWN_MSGS	/* receive my own msgs (default:off) */

};



#endif

net/can/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -15,3 +15,14 @@ menuconfig CAN 


	  If you want CAN support you should say Y here and also to the

	  specific driver for your controller(s) below.



config CAN_RAW

	tristate "Raw CAN Protocol (raw access with CAN-ID filtering)"

	depends on CAN

	default N

	---help---

	  The raw CAN protocol option offers access to the CAN bus via

	  the BSD socket API. You probably want to use the raw socket in

	  most cases where no higher level protocol is being used. The raw

	  socket has several filter options e.g. ID masking / error frames.

	  To receive/send raw CAN messages, use AF_CAN with protocol CAN_RAW.

net/can/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -4,3 +4,6 @@ 


obj-$(CONFIG_CAN)	+= can.o

can-objs		:= af_can.o proc.o



obj-$(CONFIG_CAN_RAW)	+= can-raw.o

can-raw-objs		:= raw.o

net/can/raw.c

0 → 100644
+763 −0
Original line number Diff line number Diff line 
/*

 * raw.c - Raw sockets for protocol family CAN

 *

 * 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/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/raw.h>

#include <net/sock.h>

#include <net/net_namespace.h>



#define CAN_RAW_VERSION CAN_VERSION

static __initdata const char banner[] =

	KERN_INFO "can: raw protocol (rev " CAN_RAW_VERSION ")\n";



MODULE_DESCRIPTION("PF_CAN raw protocol");

MODULE_LICENSE("Dual BSD/GPL");

MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");



#define MASK_ALL 0



/*

 * A raw socket has a list of can_filters attached to it, each receiving

 * the CAN frames matching that filter.  If the filter list is empty,

 * no CAN frames will be received by the socket.  The default after

 * opening the socket, is to have one filter which receives all frames.

 * The filter list is allocated dynamically with the exception of the

 * list containing only one item.  This common case is optimized by

 * storing the single filter in dfilter, to avoid using dynamic memory.

 */



struct raw_sock {

	struct sock sk;

	int bound;

	int ifindex;

	struct notifier_block notifier;

	int loopback;

	int recv_own_msgs;

	int count;                 /* number of active filters */

	struct can_filter dfilter; /* default/single filter */

	struct can_filter *filter; /* pointer to filter(s) */

	can_err_mask_t err_mask;

};



static inline struct raw_sock *raw_sk(const struct sock *sk)

{

	return (struct raw_sock *)sk;

}



static void raw_rcv(struct sk_buff *skb, void *data)

{

	struct sock *sk = (struct sock *)data;

	struct raw_sock *ro = raw_sk(sk);

	struct sockaddr_can *addr;

	int error;



	if (!ro->recv_own_msgs) {

		/* check the received tx sock reference */

		if (skb->sk == sk) {

			kfree_skb(skb);

			return;

		}

	}



	/*

	 *  Put the datagram to the queue so that raw_recvmsg() can

	 *  get it from there.  We need to pass the interface index to

	 *  raw_recvmsg().  We pass a whole struct sockaddr_can in skb->cb

	 *  containing the interface index.

	 */



	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));

	addr = (struct sockaddr_can *)skb->cb;

	memset(addr, 0, sizeof(*addr));

	addr->can_family  = AF_CAN;

	addr->can_ifindex = skb->dev->ifindex;



	error = sock_queue_rcv_skb(sk, skb);

	if (error < 0)

		kfree_skb(skb);

}



static int raw_enable_filters(struct net_device *dev, struct sock *sk,

			      struct can_filter *filter,

			      int count)

{

	int err = 0;

	int i;



	for (i = 0; i < count; i++) {

		err = can_rx_register(dev, filter[i].can_id,

				      filter[i].can_mask,

				      raw_rcv, sk, "raw");

		if (err) {

			/* clean up successfully registered filters */

			while (--i >= 0)

				can_rx_unregister(dev, filter[i].can_id,

						  filter[i].can_mask,

						  raw_rcv, sk);

			break;

		}

	}



	return err;

}



static int raw_enable_errfilter(struct net_device *dev, struct sock *sk,

				can_err_mask_t err_mask)

{

	int err = 0;



	if (err_mask)

		err = can_rx_register(dev, 0, err_mask | CAN_ERR_FLAG,

				      raw_rcv, sk, "raw");



	return err;

}



static void raw_disable_filters(struct net_device *dev, struct sock *sk,

			      struct can_filter *filter,

			      int count)

{

	int i;



	for (i = 0; i < count; i++)

		can_rx_unregister(dev, filter[i].can_id, filter[i].can_mask,

				  raw_rcv, sk);

}



static inline void raw_disable_errfilter(struct net_device *dev,

					 struct sock *sk,

					 can_err_mask_t err_mask)



{

	if (err_mask)

		can_rx_unregister(dev, 0, err_mask | CAN_ERR_FLAG,

				  raw_rcv, sk);

}



static inline void raw_disable_allfilters(struct net_device *dev,

					  struct sock *sk)

{

	struct raw_sock *ro = raw_sk(sk);



	raw_disable_filters(dev, sk, ro->filter, ro->count);

	raw_disable_errfilter(dev, sk, ro->err_mask);

}



static int raw_enable_allfilters(struct net_device *dev, struct sock *sk)

{

	struct raw_sock *ro = raw_sk(sk);

	int err;



	err = raw_enable_filters(dev, sk, ro->filter, ro->count);

	if (!err) {

		err = raw_enable_errfilter(dev, sk, ro->err_mask);

		if (err)

			raw_disable_filters(dev, sk, ro->filter, ro->count);

	}



	return err;

}



static int raw_notifier(struct notifier_block *nb,

			unsigned long msg, void *data)

{

	struct net_device *dev = (struct net_device *)data;

	struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);

	struct sock *sk = &ro->sk;



	if (dev->nd_net != &init_net)

		return NOTIFY_DONE;



	if (dev->type != ARPHRD_CAN)

		return NOTIFY_DONE;



	if (ro->ifindex != dev->ifindex)

		return NOTIFY_DONE;



	switch (msg) {



	case NETDEV_UNREGISTER:

		lock_sock(sk);

		/* remove current filters & unregister */

		if (ro->bound)

			raw_disable_allfilters(dev, sk);



		if (ro->count > 1)

			kfree(ro->filter);



		ro->ifindex = 0;

		ro->bound   = 0;

		ro->count   = 0;

		release_sock(sk);



		sk->sk_err = ENODEV;

		if (!sock_flag(sk, SOCK_DEAD))

			sk->sk_error_report(sk);

		break;



	case NETDEV_DOWN:

		sk->sk_err = ENETDOWN;

		if (!sock_flag(sk, SOCK_DEAD))

			sk->sk_error_report(sk);

		break;

	}



	return NOTIFY_DONE;

}



static int raw_init(struct sock *sk)

{

	struct raw_sock *ro = raw_sk(sk);



	ro->bound            = 0;

	ro->ifindex          = 0;



	/* set default filter to single entry dfilter */

	ro->dfilter.can_id   = 0;

	ro->dfilter.can_mask = MASK_ALL;

	ro->filter           = &ro->dfilter;

	ro->count            = 1;



	/* set default loopback behaviour */

	ro->loopback         = 1;

	ro->recv_own_msgs    = 0;



	/* set notifier */

	ro->notifier.notifier_call = raw_notifier;



	register_netdevice_notifier(&ro->notifier);



	return 0;

}



static int raw_release(struct socket *sock)

{

	struct sock *sk = sock->sk;

	struct raw_sock *ro = raw_sk(sk);



	unregister_netdevice_notifier(&ro->notifier);



	lock_sock(sk);



	/* remove current filters & unregister */

	if (ro->bound) {

		if (ro->ifindex) {

			struct net_device *dev;



			dev = dev_get_by_index(&init_net, ro->ifindex);

			if (dev) {

				raw_disable_allfilters(dev, sk);

				dev_put(dev);

			}

		} else

			raw_disable_allfilters(NULL, sk);

	}



	if (ro->count > 1)

		kfree(ro->filter);



	ro->ifindex = 0;

	ro->bound   = 0;

	ro->count   = 0;



	release_sock(sk);

	sock_put(sk);



	return 0;

}



static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)

{

	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;

	struct sock *sk = sock->sk;

	struct raw_sock *ro = raw_sk(sk);

	int ifindex;

	int err = 0;

	int notify_enetdown = 0;



	if (len < sizeof(*addr))

		return -EINVAL;



	lock_sock(sk);



	if (ro->bound && addr->can_ifindex == ro->ifindex)

		goto out;



	if (addr->can_ifindex) {

		struct net_device *dev;



		dev = dev_get_by_index(&init_net, addr->can_ifindex);

		if (!dev) {

			err = -ENODEV;

			goto out;

		}

		if (dev->type != ARPHRD_CAN) {

			dev_put(dev);

			err = -ENODEV;

			goto out;

		}

		if (!(dev->flags & IFF_UP))

			notify_enetdown = 1;



		ifindex = dev->ifindex;



		/* filters set by default/setsockopt */

		err = raw_enable_allfilters(dev, sk);

		dev_put(dev);



	} else {

		ifindex = 0;



		/* filters set by default/setsockopt */

		err = raw_enable_allfilters(NULL, sk);

	}



	if (!err) {

		if (ro->bound) {

			/* unregister old filters */

			if (ro->ifindex) {

				struct net_device *dev;



				dev = dev_get_by_index(&init_net, ro->ifindex);

				if (dev) {

					raw_disable_allfilters(dev, sk);

					dev_put(dev);

				}

			} else

				raw_disable_allfilters(NULL, sk);

		}

		ro->ifindex = ifindex;

		ro->bound = 1;

	}



 out:

	release_sock(sk);



	if (notify_enetdown) {

		sk->sk_err = ENETDOWN;

		if (!sock_flag(sk, SOCK_DEAD))

			sk->sk_error_report(sk);

	}



	return err;

}



static int raw_getname(struct socket *sock, struct sockaddr *uaddr,

		       int *len, int peer)

{

	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;

	struct sock *sk = sock->sk;

	struct raw_sock *ro = raw_sk(sk);



	if (peer)

		return -EOPNOTSUPP;



	addr->can_family  = AF_CAN;

	addr->can_ifindex = ro->ifindex;



	*len = sizeof(*addr);



	return 0;

}



static int raw_setsockopt(struct socket *sock, int level, int optname,

			  char __user *optval, int optlen)

{

	struct sock *sk = sock->sk;

	struct raw_sock *ro = raw_sk(sk);

	struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */

	struct can_filter sfilter;         /* single filter */

	struct net_device *dev = NULL;

	can_err_mask_t err_mask = 0;

	int count = 0;

	int err = 0;



	if (level != SOL_CAN_RAW)

		return -EINVAL;

	if (optlen < 0)

		return -EINVAL;



	switch (optname) {



	case CAN_RAW_FILTER:

		if (optlen % sizeof(struct can_filter) != 0)

			return -EINVAL;



		count = optlen / sizeof(struct can_filter);



		if (count > 1) {

			/* filter does not fit into dfilter => alloc space */

			filter = kmalloc(optlen, GFP_KERNEL);

			if (!filter)

				return -ENOMEM;



			err = copy_from_user(filter, optval, optlen);

			if (err) {

				kfree(filter);

				return err;

			}

		} else if (count == 1) {

			err = copy_from_user(&sfilter, optval, optlen);

			if (err)

				return err;

		}



		lock_sock(sk);



		if (ro->bound && ro->ifindex)

			dev = dev_get_by_index(&init_net, ro->ifindex);



		if (ro->bound) {

			/* (try to) register the new filters */

			if (count == 1)

				err = raw_enable_filters(dev, sk, &sfilter, 1);

			else

				err = raw_enable_filters(dev, sk, filter,

							 count);

			if (err) {

				if (count > 1)

					kfree(filter);



				goto out_fil;

			}



			/* remove old filter registrations */

			raw_disable_filters(dev, sk, ro->filter, ro->count);

		}



		/* remove old filter space */

		if (ro->count > 1)

			kfree(ro->filter);



		/* link new filters to the socket */

		if (count == 1) {

			/* copy filter data for single filter */

			ro->dfilter = sfilter;

			filter = &ro->dfilter;

		}

		ro->filter = filter;

		ro->count  = count;



 out_fil:

		if (dev)

			dev_put(dev);



		release_sock(sk);



		break;



	case CAN_RAW_ERR_FILTER:

		if (optlen != sizeof(err_mask))

			return -EINVAL;



		err = copy_from_user(&err_mask, optval, optlen);

		if (err)

			return err;



		err_mask &= CAN_ERR_MASK;



		lock_sock(sk);



		if (ro->bound && ro->ifindex)

			dev = dev_get_by_index(&init_net, ro->ifindex);



		/* remove current error mask */

		if (ro->bound) {

			/* (try to) register the new err_mask */

			err = raw_enable_errfilter(dev, sk, err_mask);



			if (err)

				goto out_err;



			/* remove old err_mask registration */

			raw_disable_errfilter(dev, sk, ro->err_mask);

		}



		/* link new err_mask to the socket */

		ro->err_mask = err_mask;



 out_err:

		if (dev)

			dev_put(dev);



		release_sock(sk);



		break;



	case CAN_RAW_LOOPBACK:

		if (optlen != sizeof(ro->loopback))

			return -EINVAL;



		err = copy_from_user(&ro->loopback, optval, optlen);



		break;



	case CAN_RAW_RECV_OWN_MSGS:

		if (optlen != sizeof(ro->recv_own_msgs))

			return -EINVAL;



		err = copy_from_user(&ro->recv_own_msgs, optval, optlen);



		break;



	default:

		return -ENOPROTOOPT;

	}

	return err;

}



static int raw_getsockopt(struct socket *sock, int level, int optname,

			  char __user *optval, int __user *optlen)

{

	struct sock *sk = sock->sk;

	struct raw_sock *ro = raw_sk(sk);

	int len;

	void *val;

	int err = 0;



	if (level != SOL_CAN_RAW)

		return -EINVAL;

	if (get_user(len, optlen))

		return -EFAULT;

	if (len < 0)

		return -EINVAL;



	switch (optname) {



	case CAN_RAW_FILTER:

		lock_sock(sk);

		if (ro->count > 0) {

			int fsize = ro->count * sizeof(struct can_filter);

			if (len > fsize)

				len = fsize;

			err = copy_to_user(optval, ro->filter, len);

		} else

			len = 0;

		release_sock(sk);



		if (!err)

			err = put_user(len, optlen);

		return err;



	case CAN_RAW_ERR_FILTER:

		if (len > sizeof(can_err_mask_t))

			len = sizeof(can_err_mask_t);

		val = &ro->err_mask;

		break;



	case CAN_RAW_LOOPBACK:

		if (len > sizeof(int))

			len = sizeof(int);

		val = &ro->loopback;

		break;



	case CAN_RAW_RECV_OWN_MSGS:

		if (len > sizeof(int))

			len = sizeof(int);

		val = &ro->recv_own_msgs;

		break;



	default:

		return -ENOPROTOOPT;

	}



	if (put_user(len, optlen))

		return -EFAULT;

	if (copy_to_user(optval, val, len))

		return -EFAULT;

	return 0;

}



static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,

		       struct msghdr *msg, size_t size)

{

	struct sock *sk = sock->sk;

	struct raw_sock *ro = raw_sk(sk);

	struct sk_buff *skb;

	struct net_device *dev;

	int ifindex;

	int err;



	if (msg->msg_name) {

		struct sockaddr_can *addr =

			(struct sockaddr_can *)msg->msg_name;



		if (addr->can_family != AF_CAN)

			return -EINVAL;



		ifindex = addr->can_ifindex;

	} else

		ifindex = ro->ifindex;



	dev = dev_get_by_index(&init_net, ifindex);

	if (!dev)

		return -ENXIO;



	skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,

				  &err);

	if (!skb) {

		dev_put(dev);

		return err;

	}



	err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);

	if (err < 0) {

		kfree_skb(skb);

		dev_put(dev);

		return err;

	}

	skb->dev = dev;

	skb->sk  = sk;



	err = can_send(skb, ro->loopback);



	dev_put(dev);



	if (err)

		return err;



	return size;

}



static int raw_recvmsg(struct kiocb *iocb, struct socket *sock,

		       struct msghdr *msg, size_t size, int flags)

{

	struct sock *sk = sock->sk;

	struct sk_buff *skb;

	int error = 0;

	int noblock;



	noblock =  flags & MSG_DONTWAIT;

	flags   &= ~MSG_DONTWAIT;



	skb = skb_recv_datagram(sk, flags, noblock, &error);

	if (!skb)

		return error;



	if (size < skb->len)

		msg->msg_flags |= MSG_TRUNC;

	else

		size = skb->len;



	error = memcpy_toiovec(msg->msg_iov, skb->data, size);

	if (error < 0) {

		skb_free_datagram(sk, skb);

		return error;

	}



	sock_recv_timestamp(msg, sk, skb);



	if (msg->msg_name) {

		msg->msg_namelen = sizeof(struct sockaddr_can);

		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);

	}



	skb_free_datagram(sk, skb);



	return size;

}



static struct proto_ops raw_ops __read_mostly = {

	.family        = PF_CAN,

	.release       = raw_release,

	.bind          = raw_bind,

	.connect       = sock_no_connect,

	.socketpair    = sock_no_socketpair,

	.accept        = sock_no_accept,

	.getname       = raw_getname,

	.poll          = datagram_poll,

	.ioctl         = NULL,		/* use can_ioctl() from af_can.c */

	.listen        = sock_no_listen,

	.shutdown      = sock_no_shutdown,

	.setsockopt    = raw_setsockopt,

	.getsockopt    = raw_getsockopt,

	.sendmsg       = raw_sendmsg,

	.recvmsg       = raw_recvmsg,

	.mmap          = sock_no_mmap,

	.sendpage      = sock_no_sendpage,

};



static struct proto raw_proto __read_mostly = {

	.name       = "CAN_RAW",

	.owner      = THIS_MODULE,

	.obj_size   = sizeof(struct raw_sock),

	.init       = raw_init,

};



static struct can_proto raw_can_proto __read_mostly = {

	.type       = SOCK_RAW,

	.protocol   = CAN_RAW,

	.capability = -1,

	.ops        = &raw_ops,

	.prot       = &raw_proto,

};



static __init int raw_module_init(void)

{

	int err;



	printk(banner);



	err = can_proto_register(&raw_can_proto);

	if (err < 0)

		printk(KERN_ERR "can: registration of raw protocol failed\n");



	return err;

}



static __exit void raw_module_exit(void)

{

	can_proto_unregister(&raw_can_proto);

}



module_init(raw_module_init);

module_exit(raw_module_exit);