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linux/net/can/raw.c

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/*
* 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 {
int skbcnt;
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 &&
this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
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)->skbcnt = can_skb_prv(oskb)->skbcnt;
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 *net, 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(net, dev, filter[i].can_id,
filter[i].can_mask,
raw_rcv, sk, "raw", sk);
if (err) {
/* clean up successfully registered filters */
while (--i >= 0)
can_rx_unregister(net, dev, filter[i].can_id,
filter[i].can_mask,
raw_rcv, sk);
break;
}
}
return err;
}
static int raw_enable_errfilter(struct net *net, struct net_device *dev,
struct sock *sk, can_err_mask_t err_mask)
{
int err = 0;
if (err_mask)
err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
raw_rcv, sk, "raw", sk);
return err;
}
static void raw_disable_filters(struct net *net, struct net_device *dev,
struct sock *sk, struct can_filter *filter,
int count)
{
int i;
for (i = 0; i < count; i++)
can_rx_unregister(net, dev, filter[i].can_id,
filter[i].can_mask, raw_rcv, sk);
}
static inline void raw_disable_errfilter(struct net *net,
struct net_device *dev,
struct sock *sk,
can_err_mask_t err_mask)
{
if (err_mask)
can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
raw_rcv, sk);
}
static inline void raw_disable_allfilters(struct net *net,
struct net_device *dev,
struct sock *sk)
{
struct raw_sock *ro = raw_sk(sk);
raw_disable_filters(net, dev, sk, ro->filter, ro->count);
raw_disable_errfilter(net, dev, sk, ro->err_mask);
}
static int raw_enable_allfilters(struct net *net, struct net_device *dev,
struct sock *sk)
{
struct raw_sock *ro = raw_sk(sk);
int err;
err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
if (!err) {
err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
if (err)
raw_disable_filters(net, 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), sock_net(sk)))
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_net(dev), 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(sock_net(sk), ro->ifindex);
if (dev) {
raw_disable_allfilters(dev_net(dev), dev, sk);
dev_put(dev);
}
} else
raw_disable_allfilters(sock_net(sk), 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(sock_net(sk), 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(sock_net(sk), dev, sk);
dev_put(dev);
} else {
ifindex = 0;
/* filters set by default/setsockopt */
err = raw_enable_allfilters(sock_net(sk), NULL, sk);
}
if (!err) {
if (ro->bound) {
/* unregister old filters */
if (ro->ifindex) {
struct net_device *dev;
dev = dev_get_by_index(sock_net(sk),
ro->ifindex);
if (dev) {
raw_disable_allfilters(dev_net(dev),
dev, sk);
dev_put(dev);
}
} else
raw_disable_allfilters(sock_net(sk), 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;
if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
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(sock_net(sk), ro->ifindex);
if (ro->bound) {
/* (try to) register the new filters */
if (count == 1)
err = raw_enable_filters(sock_net(sk), dev, sk,
&sfilter, 1);
else
err = raw_enable_filters(sock_net(sk), dev, sk,
filter, count);
if (err) {
if (count > 1)
kfree(filter);
goto out_fil;
}
/* remove old filter registrations */
raw_disable_filters(sock_net(sk), 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(sock_net(sk), ro->ifindex);
/* remove current error mask */
if (ro->bound) {
/* (try to) register the new err_mask */
err = raw_enable_errfilter(sock_net(sk), dev, sk,
err_mask);
if (err)
goto out_err;
/* remove old err_mask registration */
raw_disable_errfilter(sock_net(sk), 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(sock_net(sk), 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;
can_skb_prv(skb)->skbcnt = 0;
err = memcpy_from_msg(skb_put(skb, size), msg, size);
if (err < 0)
goto free_skb;
sock_tx_timestamp(sk, sk->sk_tsflags, &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);
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