linux/net/can/raw.c
Marc Kleine-Budde 00bf80c437 can: raw: raw_getsockopt(): reduce scope of err
Reduce the scope of the variable "err" to the individual cases. This
is to avoid the mistake of setting "err" in the mistaken belief that
it will be evaluated later.

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20240220-raw-setsockopt-v1-1-7d34cb1377fc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2024-02-20 09:40:46 +01:00

1106 lines
26 KiB
C

// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
/* 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/dev.h> /* for can_is_canxl_dev_mtu() */
#include <linux/can/skb.h>
#include <linux/can/raw.h>
#include <net/sock.h>
#include <net/net_namespace.h>
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 RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
#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 net_device *dev;
netdevice_tracker dev_tracker;
struct list_head notifier;
int loopback;
int recv_own_msgs;
int fd_frames;
int xl_frames;
struct can_raw_vcid_options raw_vcid_opts;
canid_t tx_vcid_shifted;
canid_t rx_vcid_shifted;
canid_t rx_vcid_mask_shifted;
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;
};
static LIST_HEAD(raw_notifier_list);
static DEFINE_SPINLOCK(raw_notifier_lock);
static struct raw_sock *raw_busy_notifier;
/* 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;
/* make sure to not pass oversized frames to the socket */
if (!ro->fd_frames && can_is_canfd_skb(oskb))
return;
if (can_is_canxl_skb(oskb)) {
struct canxl_frame *cxl = (struct canxl_frame *)oskb->data;
/* make sure to not pass oversized frames to the socket */
if (!ro->xl_frames)
return;
/* filter CAN XL VCID content */
if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_RX_FILTER) {
/* apply VCID filter if user enabled the filter */
if ((cxl->prio & ro->rx_vcid_mask_shifted) !=
(ro->rx_vcid_shifted & ro->rx_vcid_mask_shifted))
return;
} else {
/* no filter => do not forward VCID tagged frames */
if (cxl->prio & CANXL_VCID_MASK)
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)
return;
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 {
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 void raw_notify(struct raw_sock *ro, unsigned long msg,
struct net_device *dev)
{
struct sock *sk = &ro->sk;
if (!net_eq(dev_net(dev), sock_net(sk)))
return;
if (ro->dev != dev)
return;
switch (msg) {
case NETDEV_UNREGISTER:
lock_sock(sk);
/* remove current filters & unregister */
if (ro->bound) {
raw_disable_allfilters(dev_net(dev), dev, sk);
netdev_put(dev, &ro->dev_tracker);
}
if (ro->count > 1)
kfree(ro->filter);
ro->ifindex = 0;
ro->bound = 0;
ro->dev = NULL;
ro->count = 0;
release_sock(sk);
sk->sk_err = ENODEV;
if (!sock_flag(sk, SOCK_DEAD))
sk_error_report(sk);
break;
case NETDEV_DOWN:
sk->sk_err = ENETDOWN;
if (!sock_flag(sk, SOCK_DEAD))
sk_error_report(sk);
break;
}
}
static int raw_notifier(struct notifier_block *nb, unsigned long msg,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
return NOTIFY_DONE;
if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
return NOTIFY_DONE;
spin_lock(&raw_notifier_lock);
list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
spin_unlock(&raw_notifier_lock);
raw_notify(raw_busy_notifier, msg, dev);
spin_lock(&raw_notifier_lock);
}
raw_busy_notifier = NULL;
spin_unlock(&raw_notifier_lock);
return NOTIFY_DONE;
}
static int raw_init(struct sock *sk)
{
struct raw_sock *ro = raw_sk(sk);
ro->bound = 0;
ro->ifindex = 0;
ro->dev = NULL;
/* 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->xl_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 */
spin_lock(&raw_notifier_lock);
list_add_tail(&ro->notifier, &raw_notifier_list);
spin_unlock(&raw_notifier_lock);
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);
spin_lock(&raw_notifier_lock);
while (raw_busy_notifier == ro) {
spin_unlock(&raw_notifier_lock);
schedule_timeout_uninterruptible(1);
spin_lock(&raw_notifier_lock);
}
list_del(&ro->notifier);
spin_unlock(&raw_notifier_lock);
rtnl_lock();
lock_sock(sk);
/* remove current filters & unregister */
if (ro->bound) {
if (ro->dev) {
raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk);
netdev_put(ro->dev, &ro->dev_tracker);
} else {
raw_disable_allfilters(sock_net(sk), NULL, sk);
}
}
if (ro->count > 1)
kfree(ro->filter);
ro->ifindex = 0;
ro->bound = 0;
ro->dev = NULL;
ro->count = 0;
free_percpu(ro->uniq);
sock_orphan(sk);
sock->sk = NULL;
release_sock(sk);
rtnl_unlock();
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);
struct net_device *dev = NULL;
int ifindex;
int err = 0;
int notify_enetdown = 0;
if (len < RAW_MIN_NAMELEN)
return -EINVAL;
if (addr->can_family != AF_CAN)
return -EINVAL;
rtnl_lock();
lock_sock(sk);
if (ro->bound && addr->can_ifindex == ro->ifindex)
goto out;
if (addr->can_ifindex) {
dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
if (!dev) {
err = -ENODEV;
goto out;
}
if (dev->type != ARPHRD_CAN) {
err = -ENODEV;
goto out_put_dev;
}
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);
if (err)
goto out_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->dev) {
raw_disable_allfilters(dev_net(ro->dev),
ro->dev, sk);
/* drop reference to old ro->dev */
netdev_put(ro->dev, &ro->dev_tracker);
} else {
raw_disable_allfilters(sock_net(sk), NULL, sk);
}
}
ro->ifindex = ifindex;
ro->bound = 1;
/* bind() ok -> hold a reference for new ro->dev */
ro->dev = dev;
if (ro->dev)
netdev_hold(ro->dev, &ro->dev_tracker, GFP_KERNEL);
}
out_put_dev:
/* remove potential reference from dev_get_by_index() */
dev_put(dev);
out:
release_sock(sk);
rtnl_unlock();
if (notify_enetdown) {
sk->sk_err = ENETDOWN;
if (!sock_flag(sk, SOCK_DEAD))
sk_error_report(sk);
}
return err;
}
static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
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, RAW_MIN_NAMELEN);
addr->can_family = AF_CAN;
addr->can_ifindex = ro->ifindex;
return RAW_MIN_NAMELEN;
}
static int raw_setsockopt(struct socket *sock, int level, int optname,
sockptr_t 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 fd_frames;
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_sockptr(optval, optlen);
if (IS_ERR(filter))
return PTR_ERR(filter);
} else if (count == 1) {
if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter)))
return -EFAULT;
}
rtnl_lock();
lock_sock(sk);
dev = ro->dev;
if (ro->bound && dev) {
if (dev->reg_state != NETREG_REGISTERED) {
if (count > 1)
kfree(filter);
err = -ENODEV;
goto out_fil;
}
}
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:
release_sock(sk);
rtnl_unlock();
break;
case CAN_RAW_ERR_FILTER:
if (optlen != sizeof(err_mask))
return -EINVAL;
if (copy_from_sockptr(&err_mask, optval, optlen))
return -EFAULT;
err_mask &= CAN_ERR_MASK;
rtnl_lock();
lock_sock(sk);
dev = ro->dev;
if (ro->bound && dev) {
if (dev->reg_state != NETREG_REGISTERED) {
err = -ENODEV;
goto out_err;
}
}
/* 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:
release_sock(sk);
rtnl_unlock();
break;
case CAN_RAW_LOOPBACK:
if (optlen != sizeof(ro->loopback))
return -EINVAL;
if (copy_from_sockptr(&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_sockptr(&ro->recv_own_msgs, optval, optlen))
return -EFAULT;
break;
case CAN_RAW_FD_FRAMES:
if (optlen != sizeof(fd_frames))
return -EINVAL;
if (copy_from_sockptr(&fd_frames, optval, optlen))
return -EFAULT;
/* Enabling CAN XL includes CAN FD */
if (ro->xl_frames && !fd_frames)
return -EINVAL;
ro->fd_frames = fd_frames;
break;
case CAN_RAW_XL_FRAMES:
if (optlen != sizeof(ro->xl_frames))
return -EINVAL;
if (copy_from_sockptr(&ro->xl_frames, optval, optlen))
return -EFAULT;
/* Enabling CAN XL includes CAN FD */
if (ro->xl_frames)
ro->fd_frames = ro->xl_frames;
break;
case CAN_RAW_XL_VCID_OPTS:
if (optlen != sizeof(ro->raw_vcid_opts))
return -EINVAL;
if (copy_from_sockptr(&ro->raw_vcid_opts, optval, optlen))
return -EFAULT;
/* prepare 32 bit values for handling in hot path */
ro->tx_vcid_shifted = ro->raw_vcid_opts.tx_vcid << CANXL_VCID_OFFSET;
ro->rx_vcid_shifted = ro->raw_vcid_opts.rx_vcid << CANXL_VCID_OFFSET;
ro->rx_vcid_mask_shifted = ro->raw_vcid_opts.rx_vcid_mask << CANXL_VCID_OFFSET;
break;
case CAN_RAW_JOIN_FILTERS:
if (optlen != sizeof(ro->join_filters))
return -EINVAL;
if (copy_from_sockptr(&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;
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: {
int err = 0;
lock_sock(sk);
if (ro->count > 0) {
int fsize = ro->count * sizeof(struct can_filter);
/* user space buffer to small for filter list? */
if (len < fsize) {
/* return -ERANGE and needed space in optlen */
err = -ERANGE;
if (put_user(fsize, optlen))
err = -EFAULT;
} else {
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_XL_FRAMES:
if (len > sizeof(int))
len = sizeof(int);
val = &ro->xl_frames;
break;
case CAN_RAW_XL_VCID_OPTS: {
int err = 0;
/* user space buffer to small for VCID opts? */
if (len < sizeof(ro->raw_vcid_opts)) {
/* return -ERANGE and needed space in optlen */
err = -ERANGE;
if (put_user(sizeof(ro->raw_vcid_opts), optlen))
err = -EFAULT;
} else {
if (len > sizeof(ro->raw_vcid_opts))
len = sizeof(ro->raw_vcid_opts);
if (copy_to_user(optval, &ro->raw_vcid_opts, len))
err = -EFAULT;
}
if (!err)
err = put_user(len, optlen);
return err;
}
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 void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb)
{
struct canxl_frame *cxl = (struct canxl_frame *)skb->data;
/* sanitize non CAN XL bits */
cxl->prio &= (CANXL_PRIO_MASK | CANXL_VCID_MASK);
/* clear VCID in CAN XL frame if pass through is disabled */
if (!(ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_PASS))
cxl->prio &= CANXL_PRIO_MASK;
/* set VCID in CAN XL frame if enabled */
if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_SET) {
cxl->prio &= CANXL_PRIO_MASK;
cxl->prio |= ro->tx_vcid_shifted;
}
}
static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu)
{
/* Classical CAN -> no checks for flags and device capabilities */
if (can_is_can_skb(skb))
return CAN_MTU;
/* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */
if (ro->fd_frames && can_is_canfd_skb(skb) &&
(mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu)))
return CANFD_MTU;
/* CAN XL -> needs to be enabled and a CAN XL device */
if (ro->xl_frames && can_is_canxl_skb(skb) &&
can_is_canxl_dev_mtu(mtu))
return CANXL_MTU;
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 sockcm_cookie sockc;
struct sk_buff *skb;
struct net_device *dev;
unsigned int txmtu;
int ifindex;
int err = -EINVAL;
/* check for valid CAN frame sizes */
if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU)
return -EINVAL;
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
if (msg->msg_namelen < RAW_MIN_NAMELEN)
return -EINVAL;
if (addr->can_family != AF_CAN)
return -EINVAL;
ifindex = addr->can_ifindex;
} else {
ifindex = ro->ifindex;
}
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;
/* fill the skb before testing for valid CAN frames */
err = memcpy_from_msg(skb_put(skb, size), msg, size);
if (err < 0)
goto free_skb;
err = -EINVAL;
/* check for valid CAN (CC/FD/XL) frame content */
txmtu = raw_check_txframe(ro, skb, dev->mtu);
if (!txmtu)
goto free_skb;
/* only CANXL: clear/forward/set VCID value */
if (txmtu == CANXL_MTU)
raw_put_canxl_vcid(ro, skb);
sockcm_init(&sockc, sk);
if (msg->msg_controllen) {
err = sock_cmsg_send(sk, msg, &sockc);
if (unlikely(err))
goto free_skb;
}
skb->dev = dev;
skb->priority = READ_ONCE(sk->sk_priority);
skb->mark = READ_ONCE(sk->sk_mark);
skb->tstamp = sockc.transmit_time;
skb_setup_tx_timestamp(skb, sockc.tsflags);
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;
if (flags & MSG_ERRQUEUE)
return sock_recv_errqueue(sk, msg, size,
SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
skb = skb_recv_datagram(sk, flags, &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_cmsgs(msg, sk, skb);
if (msg->msg_name) {
__sockaddr_check_size(RAW_MIN_NAMELEN);
msg->msg_namelen = RAW_MIN_NAMELEN;
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 int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
unsigned long arg)
{
/* no ioctls for socket layer -> hand it down to NIC layer */
return -ENOIOCTLCMD;
}
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 = raw_sock_no_ioctlcmd,
.gettstamp = sock_gettstamp,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = raw_setsockopt,
.getsockopt = raw_getsockopt,
.sendmsg = raw_sendmsg,
.recvmsg = raw_recvmsg,
.mmap = sock_no_mmap,
};
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 struct notifier_block canraw_notifier = {
.notifier_call = raw_notifier
};
static __init int raw_module_init(void)
{
int err;
pr_info("can: raw protocol\n");
err = register_netdevice_notifier(&canraw_notifier);
if (err)
return err;
err = can_proto_register(&raw_can_proto);
if (err < 0) {
pr_err("can: registration of raw protocol failed\n");
goto register_proto_failed;
}
return 0;
register_proto_failed:
unregister_netdevice_notifier(&canraw_notifier);
return err;
}
static __exit void raw_module_exit(void)
{
can_proto_unregister(&raw_can_proto);
unregister_netdevice_notifier(&canraw_notifier);
}
module_init(raw_module_init);
module_exit(raw_module_exit);