Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / can / raw.c
diff --git a/kernel/net/can/raw.c b/kernel/net/can/raw.c
new file mode 100644 (file)
index 0000000..31b9748
--- /dev/null
@@ -0,0 +1,875 @@
+/*
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/slab.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/skb.h>
+#include <linux/can/raw.h>
+#include <net/sock.h>
+#include <net/net_namespace.h>
+
+#define CAN_RAW_VERSION CAN_VERSION
+
+MODULE_DESCRIPTION("PF_CAN raw protocol");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
+MODULE_ALIAS("can-proto-1");
+
+#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 uniqframe {
+       ktime_t tstamp;
+       const struct sk_buff *skb;
+       unsigned int join_rx_count;
+};
+
+struct raw_sock {
+       struct sock sk;
+       int bound;
+       int ifindex;
+       struct notifier_block notifier;
+       int loopback;
+       int recv_own_msgs;
+       int fd_frames;
+       int join_filters;
+       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;
+       struct uniqframe __percpu *uniq;
+};
+
+/*
+ * Return pointer to store the extra msg flags for raw_recvmsg().
+ * We use the space of one unsigned int beyond the 'struct sockaddr_can'
+ * in skb->cb.
+ */
+static inline unsigned int *raw_flags(struct sk_buff *skb)
+{
+       sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
+                              sizeof(unsigned int));
+
+       /* return pointer after struct sockaddr_can */
+       return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
+}
+
+static inline struct raw_sock *raw_sk(const struct sock *sk)
+{
+       return (struct raw_sock *)sk;
+}
+
+static void raw_rcv(struct sk_buff *oskb, void *data)
+{
+       struct sock *sk = (struct sock *)data;
+       struct raw_sock *ro = raw_sk(sk);
+       struct sockaddr_can *addr;
+       struct sk_buff *skb;
+       unsigned int *pflags;
+
+       /* check the received tx sock reference */
+       if (!ro->recv_own_msgs && oskb->sk == sk)
+               return;
+
+       /* do not pass non-CAN2.0 frames to a legacy socket */
+       if (!ro->fd_frames && oskb->len != CAN_MTU)
+               return;
+
+       /* eliminate multiple filter matches for the same skb */
+       if (this_cpu_ptr(ro->uniq)->skb == oskb &&
+           ktime_equal(this_cpu_ptr(ro->uniq)->tstamp, oskb->tstamp)) {
+               if (ro->join_filters) {
+                       this_cpu_inc(ro->uniq->join_rx_count);
+                       /* drop frame until all enabled filters matched */
+                       if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
+                               return;
+               } else {
+                       return;
+               }
+       } else {
+               this_cpu_ptr(ro->uniq)->skb = oskb;
+               this_cpu_ptr(ro->uniq)->tstamp = oskb->tstamp;
+               this_cpu_ptr(ro->uniq)->join_rx_count = 1;
+               /* drop first frame to check all enabled filters? */
+               if (ro->join_filters && ro->count > 1)
+                       return;
+       }
+
+       /* clone the given skb to be able to enqueue it into the rcv queue */
+       skb = skb_clone(oskb, GFP_ATOMIC);
+       if (!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.
+        */
+
+       sock_skb_cb_check_size(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;
+
+       /* add CAN specific message flags for raw_recvmsg() */
+       pflags = raw_flags(skb);
+       *pflags = 0;
+       if (oskb->sk)
+               *pflags |= MSG_DONTROUTE;
+       if (oskb->sk == sk)
+               *pflags |= MSG_CONFIRM;
+
+       if (sock_queue_rcv_skb(sk, skb) < 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 *ptr)
+{
+       struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+       struct raw_sock *ro = container_of(nb, struct raw_sock, notifier);
+       struct sock *sk = &ro->sk;
+
+       if (!net_eq(dev_net(dev), &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;
+       ro->fd_frames        = 0;
+       ro->join_filters     = 0;
+
+       /* alloc_percpu provides zero'ed memory */
+       ro->uniq = alloc_percpu(struct uniqframe);
+       if (unlikely(!ro->uniq))
+               return -ENOMEM;
+
+       /* 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;
+
+       if (!sk)
+               return 0;
+
+       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;
+       free_percpu(ro->uniq);
+
+       sock_orphan(sk);
+       sock->sk = NULL;
+
+       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;
+
+       memset(addr, 0, sizeof(*addr));
+       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, unsigned 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;
+
+       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 = memdup_user(optval, optlen);
+                       if (IS_ERR(filter))
+                               return PTR_ERR(filter);
+               } else if (count == 1) {
+                       if (copy_from_user(&sfilter, optval, sizeof(sfilter)))
+                               return -EFAULT;
+               }
+
+               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;
+
+               if (copy_from_user(&err_mask, optval, optlen))
+                       return -EFAULT;
+
+               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;
+
+               if (copy_from_user(&ro->loopback, optval, optlen))
+                       return -EFAULT;
+
+               break;
+
+       case CAN_RAW_RECV_OWN_MSGS:
+               if (optlen != sizeof(ro->recv_own_msgs))
+                       return -EINVAL;
+
+               if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
+                       return -EFAULT;
+
+               break;
+
+       case CAN_RAW_FD_FRAMES:
+               if (optlen != sizeof(ro->fd_frames))
+                       return -EINVAL;
+
+               if (copy_from_user(&ro->fd_frames, optval, optlen))
+                       return -EFAULT;
+
+               break;
+
+       case CAN_RAW_JOIN_FILTERS:
+               if (optlen != sizeof(ro->join_filters))
+                       return -EINVAL;
+
+               if (copy_from_user(&ro->join_filters, optval, optlen))
+                       return -EFAULT;
+
+               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;
+                       if (copy_to_user(optval, ro->filter, len))
+                               err = -EFAULT;
+               } 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;
+
+       case CAN_RAW_FD_FRAMES:
+               if (len > sizeof(int))
+                       len = sizeof(int);
+               val = &ro->fd_frames;
+               break;
+
+       case CAN_RAW_JOIN_FILTERS:
+               if (len > sizeof(int))
+                       len = sizeof(int);
+               val = &ro->join_filters;
+               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 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) {
+               DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
+
+               if (msg->msg_namelen < sizeof(*addr))
+                       return -EINVAL;
+
+               if (addr->can_family != AF_CAN)
+                       return -EINVAL;
+
+               ifindex = addr->can_ifindex;
+       } else
+               ifindex = ro->ifindex;
+
+       if (ro->fd_frames) {
+               if (unlikely(size != CANFD_MTU && size != CAN_MTU))
+                       return -EINVAL;
+       } else {
+               if (unlikely(size != CAN_MTU))
+                       return -EINVAL;
+       }
+
+       dev = dev_get_by_index(&init_net, ifindex);
+       if (!dev)
+               return -ENXIO;
+
+       skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
+                                 msg->msg_flags & MSG_DONTWAIT, &err);
+       if (!skb)
+               goto put_dev;
+
+       can_skb_reserve(skb);
+       can_skb_prv(skb)->ifindex = dev->ifindex;
+
+       err = memcpy_from_msg(skb_put(skb, size), msg, size);
+       if (err < 0)
+               goto free_skb;
+
+       sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
+
+       skb->dev = dev;
+       skb->sk  = sk;
+       skb->priority = sk->sk_priority;
+
+       err = can_send(skb, ro->loopback);
+
+       dev_put(dev);
+
+       if (err)
+               goto send_failed;
+
+       return size;
+
+free_skb:
+       kfree_skb(skb);
+put_dev:
+       dev_put(dev);
+send_failed:
+       return err;
+}
+
+static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+                      int flags)
+{
+       struct sock *sk = sock->sk;
+       struct sk_buff *skb;
+       int err = 0;
+       int noblock;
+
+       noblock =  flags & MSG_DONTWAIT;
+       flags   &= ~MSG_DONTWAIT;
+
+       skb = skb_recv_datagram(sk, flags, noblock, &err);
+       if (!skb)
+               return err;
+
+       if (size < skb->len)
+               msg->msg_flags |= MSG_TRUNC;
+       else
+               size = skb->len;
+
+       err = memcpy_to_msg(msg, skb->data, size);
+       if (err < 0) {
+               skb_free_datagram(sk, skb);
+               return err;
+       }
+
+       sock_recv_ts_and_drops(msg, sk, skb);
+
+       if (msg->msg_name) {
+               __sockaddr_check_size(sizeof(struct sockaddr_can));
+               msg->msg_namelen = sizeof(struct sockaddr_can);
+               memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+       }
+
+       /* assign the flags that have been recorded in raw_rcv() */
+       msg->msg_flags |= *(raw_flags(skb));
+
+       skb_free_datagram(sk, skb);
+
+       return size;
+}
+
+static const struct proto_ops raw_ops = {
+       .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         = can_ioctl,     /* 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 const struct can_proto raw_can_proto = {
+       .type       = SOCK_RAW,
+       .protocol   = CAN_RAW,
+       .ops        = &raw_ops,
+       .prot       = &raw_proto,
+};
+
+static __init int raw_module_init(void)
+{
+       int err;
+
+       pr_info("can: raw protocol (rev " CAN_RAW_VERSION ")\n");
+
+       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);