linux/net/can/raw.c
Oliver Hartkopp d3b58c47d3 can: replace timestamp as unique skb attribute
Commit 514ac99c64 "can: fix multiple delivery of a single CAN frame for
overlapping CAN filters" requires the skb->tstamp to be set to check for
identical CAN skbs.

Without timestamping to be required by user space applications this timestamp
was not generated which lead to commit 36c01245eb "can: fix loss of CAN frames
in raw_rcv" - which forces the timestamp to be set in all CAN related skbuffs
by introducing several __net_timestamp() calls.

This forces e.g. out of tree drivers which are not using alloc_can{,fd}_skb()
to add __net_timestamp() after skbuff creation to prevent the frame loss fixed
in mainline Linux.

This patch removes the timestamp dependency and uses an atomic counter to
create an unique identifier together with the skbuff pointer.

Btw: the new skbcnt element introduced in struct can_skb_priv has to be
initialized with zero in out-of-tree drivers which are not using
alloc_can{,fd}_skb() too.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2015-07-12 21:13:22 +02:00

877 lines
20 KiB
C

/*
* 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_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;
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, &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);