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linux/net/can/bcm.c

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// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
/*
* bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
*
* Copyright (c) 2002-2017 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/interrupt.h>
#include <linux/hrtimer.h>
#include <linux/list.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.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/skb.h>
#include <linux/can/bcm.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/net_namespace.h>
/*
* To send multiple CAN frame content within TX_SETUP or to filter
* CAN messages with multiplex index within RX_SETUP, the number of
* different filters is limited to 256 due to the one byte index value.
*/
#define MAX_NFRAMES 256
/* limit timers to 400 days for sending/timeouts */
#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
/* use of last_frames[index].flags */
#define RX_RECV 0x40 /* received data for this element */
#define RX_THR 0x80 /* element not been sent due to throttle feature */
#define BCM_CAN_FLAGS_MASK 0x3F /* to clean private flags after usage */
/* get best masking value for can_rx_register() for a given single can_id */
#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
(CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
(CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
MODULE_ALIAS("can-proto-2");
#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
/*
* easy access to the first 64 bit of can(fd)_frame payload. cp->data is
* 64 bit aligned so the offset has to be multiples of 8 which is ensured
* by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
*/
static inline u64 get_u64(const struct canfd_frame *cp, int offset)
{
return *(u64 *)(cp->data + offset);
}
struct bcm_op {
struct list_head list;
int ifindex;
canid_t can_id;
u32 flags;
unsigned long frames_abs, frames_filtered;
struct bcm_timeval ival1, ival2;
struct hrtimer timer, thrtimer;
ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
int rx_ifindex;
int cfsiz;
u32 count;
u32 nframes;
u32 currframe;
/* void pointers to arrays of struct can[fd]_frame */
void *frames;
void *last_frames;
struct canfd_frame sframe;
struct canfd_frame last_sframe;
struct sock *sk;
struct net_device *rx_reg_dev;
};
struct bcm_sock {
struct sock sk;
int bound;
int ifindex;
struct notifier_block notifier;
struct list_head rx_ops;
struct list_head tx_ops;
unsigned long dropped_usr_msgs;
struct proc_dir_entry *bcm_proc_read;
char procname [32]; /* inode number in decimal with \0 */
};
static inline struct bcm_sock *bcm_sk(const struct sock *sk)
{
return (struct bcm_sock *)sk;
}
static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
{
return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
}
/* check limitations for timeval provided by user */
static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
{
if ((msg_head->ival1.tv_sec < 0) ||
(msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
(msg_head->ival1.tv_usec < 0) ||
(msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
(msg_head->ival2.tv_sec < 0) ||
(msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
(msg_head->ival2.tv_usec < 0) ||
(msg_head->ival2.tv_usec >= USEC_PER_SEC))
return true;
return false;
}
#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
#define OPSIZ sizeof(struct bcm_op)
#define MHSIZ sizeof(struct bcm_msg_head)
/*
* procfs functions
*/
#if IS_ENABLED(CONFIG_PROC_FS)
static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
{
struct net_device *dev;
if (!ifindex)
return "any";
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (dev)
strcpy(result, dev->name);
else
strcpy(result, "???");
rcu_read_unlock();
return result;
}
static int bcm_proc_show(struct seq_file *m, void *v)
{
char ifname[IFNAMSIZ];
struct net *net = m->private;
struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode);
struct bcm_sock *bo = bcm_sk(sk);
struct bcm_op *op;
seq_printf(m, ">>> socket %pK", sk->sk_socket);
seq_printf(m, " / sk %pK", sk);
seq_printf(m, " / bo %pK", bo);
seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
seq_printf(m, " <<<\n");
list_for_each_entry(op, &bo->rx_ops, list) {
unsigned long reduction;
/* print only active entries & prevent division by zero */
if (!op->frames_abs)
continue;
seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
bcm_proc_getifname(net, ifname, op->ifindex));
if (op->flags & CAN_FD_FRAME)
seq_printf(m, "(%u)", op->nframes);
else
seq_printf(m, "[%u]", op->nframes);
seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
if (op->kt_ival1)
seq_printf(m, "timeo=%lld ",
(long long)ktime_to_us(op->kt_ival1));
if (op->kt_ival2)
seq_printf(m, "thr=%lld ",
(long long)ktime_to_us(op->kt_ival2));
seq_printf(m, "# recv %ld (%ld) => reduction: ",
op->frames_filtered, op->frames_abs);
reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
seq_printf(m, "%s%ld%%\n",
(reduction == 100) ? "near " : "", reduction);
}
list_for_each_entry(op, &bo->tx_ops, list) {
seq_printf(m, "tx_op: %03X %s ", op->can_id,
bcm_proc_getifname(net, ifname, op->ifindex));
if (op->flags & CAN_FD_FRAME)
seq_printf(m, "(%u) ", op->nframes);
else
seq_printf(m, "[%u] ", op->nframes);
if (op->kt_ival1)
seq_printf(m, "t1=%lld ",
(long long)ktime_to_us(op->kt_ival1));
if (op->kt_ival2)
seq_printf(m, "t2=%lld ",
(long long)ktime_to_us(op->kt_ival2));
seq_printf(m, "# sent %ld\n", op->frames_abs);
}
seq_putc(m, '\n');
return 0;
}
#endif /* CONFIG_PROC_FS */
/*
* bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
* of the given bcm tx op
*/
static void bcm_can_tx(struct bcm_op *op)
{
struct sk_buff *skb;
struct net_device *dev;
struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
/* no target device? => exit */
if (!op->ifindex)
return;
dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
if (!dev) {
/* RFC: should this bcm_op remove itself here? */
return;
}
skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
if (!skb)
goto out;
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
skb_put_data(skb, cf, op->cfsiz);
/* send with loopback */
skb->dev = dev;
can_skb_set_owner(skb, op->sk);
can_send(skb, 1);
/* update statistics */
op->currframe++;
op->frames_abs++;
/* reached last frame? */
if (op->currframe >= op->nframes)
op->currframe = 0;
out:
dev_put(dev);
}
/*
* bcm_send_to_user - send a BCM message to the userspace
* (consisting of bcm_msg_head + x CAN frames)
*/
static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
struct canfd_frame *frames, int has_timestamp)
{
struct sk_buff *skb;
struct canfd_frame *firstframe;
struct sockaddr_can *addr;
struct sock *sk = op->sk;
unsigned int datalen = head->nframes * op->cfsiz;
int err;
skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
if (!skb)
return;
skb_put_data(skb, head, sizeof(*head));
if (head->nframes) {
/* CAN frames starting here */
firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
skb_put_data(skb, frames, datalen);
/*
* the BCM uses the flags-element of the canfd_frame
* structure for internal purposes. This is only
* relevant for updates that are generated by the
* BCM, where nframes is 1
*/
if (head->nframes == 1)
firstframe->flags &= BCM_CAN_FLAGS_MASK;
}
if (has_timestamp) {
/* restore rx timestamp */
skb->tstamp = op->rx_stamp;
}
/*
* Put the datagram to the queue so that bcm_recvmsg() can
* get it from there. We need to pass the interface index to
* bcm_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 = op->rx_ifindex;
err = sock_queue_rcv_skb(sk, skb);
if (err < 0) {
struct bcm_sock *bo = bcm_sk(sk);
kfree_skb(skb);
/* don't care about overflows in this statistic */
bo->dropped_usr_msgs++;
}
}
static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
{
ktime_t ival;
if (op->kt_ival1 && op->count)
ival = op->kt_ival1;
else if (op->kt_ival2)
ival = op->kt_ival2;
else
return false;
hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
return true;
}
static void bcm_tx_start_timer(struct bcm_op *op)
{
if (bcm_tx_set_expiry(op, &op->timer))
hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
}
/* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
{
struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
struct bcm_msg_head msg_head;
if (op->kt_ival1 && (op->count > 0)) {
op->count--;
if (!op->count && (op->flags & TX_COUNTEVT)) {
/* create notification to user */
msg_head.opcode = TX_EXPIRED;
msg_head.flags = op->flags;
msg_head.count = op->count;
msg_head.ival1 = op->ival1;
msg_head.ival2 = op->ival2;
msg_head.can_id = op->can_id;
msg_head.nframes = 0;
bcm_send_to_user(op, &msg_head, NULL, 0);
}
bcm_can_tx(op);
} else if (op->kt_ival2) {
bcm_can_tx(op);
}
return bcm_tx_set_expiry(op, &op->timer) ?
HRTIMER_RESTART : HRTIMER_NORESTART;
}
/*
* bcm_rx_changed - create a RX_CHANGED notification due to changed content
*/
static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
{
struct bcm_msg_head head;
/* update statistics */
op->frames_filtered++;
/* prevent statistics overflow */
if (op->frames_filtered > ULONG_MAX/100)
op->frames_filtered = op->frames_abs = 0;
/* this element is not throttled anymore */
data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
head.opcode = RX_CHANGED;
head.flags = op->flags;
head.count = op->count;
head.ival1 = op->ival1;
head.ival2 = op->ival2;
head.can_id = op->can_id;
head.nframes = 1;
bcm_send_to_user(op, &head, data, 1);
}
/*
* bcm_rx_update_and_send - process a detected relevant receive content change
* 1. update the last received data
* 2. send a notification to the user (if possible)
*/
static void bcm_rx_update_and_send(struct bcm_op *op,
struct canfd_frame *lastdata,
const struct canfd_frame *rxdata)
{
memcpy(lastdata, rxdata, op->cfsiz);
/* mark as used and throttled by default */
lastdata->flags |= (RX_RECV|RX_THR);
/* throttling mode inactive ? */
if (!op->kt_ival2) {
/* send RX_CHANGED to the user immediately */
bcm_rx_changed(op, lastdata);
return;
}
/* with active throttling timer we are just done here */
if (hrtimer_active(&op->thrtimer))
return;
/* first reception with enabled throttling mode */
if (!op->kt_lastmsg)
goto rx_changed_settime;
/* got a second frame inside a potential throttle period? */
if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
ktime_to_us(op->kt_ival2)) {
/* do not send the saved data - only start throttle timer */
hrtimer_start(&op->thrtimer,
ktime_add(op->kt_lastmsg, op->kt_ival2),
HRTIMER_MODE_ABS_SOFT);
return;
}
/* the gap was that big, that throttling was not needed here */
rx_changed_settime:
bcm_rx_changed(op, lastdata);
op->kt_lastmsg = ktime_get();
}
/*
* bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
* received data stored in op->last_frames[]
*/
static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
const struct canfd_frame *rxdata)
{
struct canfd_frame *cf = op->frames + op->cfsiz * index;
struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
int i;
/*
* no one uses the MSBs of flags for comparison,
* so we use it here to detect the first time of reception
*/
if (!(lcf->flags & RX_RECV)) {
/* received data for the first time => send update to user */
bcm_rx_update_and_send(op, lcf, rxdata);
return;
}
/* do a real check in CAN frame data section */
for (i = 0; i < rxdata->len; i += 8) {
if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
(get_u64(cf, i) & get_u64(lcf, i))) {
bcm_rx_update_and_send(op, lcf, rxdata);
return;
}
}
if (op->flags & RX_CHECK_DLC) {
/* do a real check in CAN frame length */
if (rxdata->len != lcf->len) {
bcm_rx_update_and_send(op, lcf, rxdata);
return;
}
}
}
/*
* bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
*/
static void bcm_rx_starttimer(struct bcm_op *op)
{
if (op->flags & RX_NO_AUTOTIMER)
return;
if (op->kt_ival1)
hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
}
/* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
{
struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
struct bcm_msg_head msg_head;
/* if user wants to be informed, when cyclic CAN-Messages come back */
if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
/* clear received CAN frames to indicate 'nothing received' */
memset(op->last_frames, 0, op->nframes * op->cfsiz);
}
/* create notification to user */
msg_head.opcode = RX_TIMEOUT;
msg_head.flags = op->flags;
msg_head.count = op->count;
msg_head.ival1 = op->ival1;
msg_head.ival2 = op->ival2;
msg_head.can_id = op->can_id;
msg_head.nframes = 0;
bcm_send_to_user(op, &msg_head, NULL, 0);
return HRTIMER_NORESTART;
}
/*
* bcm_rx_do_flush - helper for bcm_rx_thr_flush
*/
static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
{
struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
if ((op->last_frames) && (lcf->flags & RX_THR)) {
bcm_rx_changed(op, lcf);
return 1;
}
return 0;
}
/*
* bcm_rx_thr_flush - Check for throttled data and send it to the userspace
*/
static int bcm_rx_thr_flush(struct bcm_op *op)
{
int updated = 0;
if (op->nframes > 1) {
unsigned int i;
/* for MUX filter we start at index 1 */
for (i = 1; i < op->nframes; i++)
updated += bcm_rx_do_flush(op, i);
} else {
/* for RX_FILTER_ID and simple filter */
updated += bcm_rx_do_flush(op, 0);
}
return updated;
}
/*
* bcm_rx_thr_handler - the time for blocked content updates is over now:
* Check for throttled data and send it to the userspace
*/
static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
{
struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
if (bcm_rx_thr_flush(op)) {
hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
return HRTIMER_RESTART;
} else {
/* rearm throttle handling */
op->kt_lastmsg = 0;
return HRTIMER_NORESTART;
}
}
/*
* bcm_rx_handler - handle a CAN frame reception
*/
static void bcm_rx_handler(struct sk_buff *skb, void *data)
{
struct bcm_op *op = (struct bcm_op *)data;
const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
unsigned int i;
if (op->can_id != rxframe->can_id)
return;
/* make sure to handle the correct frame type (CAN / CAN FD) */
if (skb->len != op->cfsiz)
return;
/* disable timeout */
hrtimer_cancel(&op->timer);
/* save rx timestamp */
op->rx_stamp = skb->tstamp;
/* save originator for recvfrom() */
op->rx_ifindex = skb->dev->ifindex;
/* update statistics */
op->frames_abs++;
if (op->flags & RX_RTR_FRAME) {
/* send reply for RTR-request (placed in op->frames[0]) */
bcm_can_tx(op);
return;
}
if (op->flags & RX_FILTER_ID) {
/* the easiest case */
bcm_rx_update_and_send(op, op->last_frames, rxframe);
goto rx_starttimer;
}
if (op->nframes == 1) {
/* simple compare with index 0 */
bcm_rx_cmp_to_index(op, 0, rxframe);
goto rx_starttimer;
}
if (op->nframes > 1) {
/*
* multiplex compare
*
* find the first multiplex mask that fits.
* Remark: The MUX-mask is stored in index 0 - but only the
* first 64 bits of the frame data[] are relevant (CAN FD)
*/
for (i = 1; i < op->nframes; i++) {
if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
(get_u64(op->frames, 0) &
get_u64(op->frames + op->cfsiz * i, 0))) {
bcm_rx_cmp_to_index(op, i, rxframe);
break;
}
}
}
rx_starttimer:
bcm_rx_starttimer(op);
}
/*
* helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
*/
static struct bcm_op *bcm_find_op(struct list_head *ops,
struct bcm_msg_head *mh, int ifindex)
{
struct bcm_op *op;
list_for_each_entry(op, ops, list) {
if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
(op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
return op;
}
return NULL;
}
static void bcm_remove_op(struct bcm_op *op)
{
hrtimer_cancel(&op->timer);
hrtimer_cancel(&op->thrtimer);
if ((op->frames) && (op->frames != &op->sframe))
kfree(op->frames);
if ((op->last_frames) && (op->last_frames != &op->last_sframe))
kfree(op->last_frames);
kfree(op);
}
static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
{
if (op->rx_reg_dev == dev) {
can_rx_unregister(dev_net(dev), dev, op->can_id,
REGMASK(op->can_id), bcm_rx_handler, op);
/* mark as removed subscription */
op->rx_reg_dev = NULL;
} else
printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
"mismatch %p %p\n", op->rx_reg_dev, dev);
}
/*
* bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
*/
static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
int ifindex)
{
struct bcm_op *op, *n;
list_for_each_entry_safe(op, n, ops, list) {
if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
(op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
/*
* Don't care if we're bound or not (due to netdev
* problems) can_rx_unregister() is always a save
* thing to do here.
*/
if (op->ifindex) {
/*
* Only remove subscriptions that had not
* been removed due to NETDEV_UNREGISTER
* in bcm_notifier()
*/
if (op->rx_reg_dev) {
struct net_device *dev;
dev = dev_get_by_index(sock_net(op->sk),
op->ifindex);
if (dev) {
bcm_rx_unreg(dev, op);
dev_put(dev);
}
}
} else
can_rx_unregister(sock_net(op->sk), NULL,
op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op);
list_del(&op->list);
bcm_remove_op(op);
return 1; /* done */
}
}
return 0; /* not found */
}
/*
* bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
*/
static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
int ifindex)
{
struct bcm_op *op, *n;
list_for_each_entry_safe(op, n, ops, list) {
if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
(op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
list_del(&op->list);
bcm_remove_op(op);
return 1; /* done */
}
}
return 0; /* not found */
}
/*
* bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
*/
static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
int ifindex)
{
struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
if (!op)
return -EINVAL;
/* put current values into msg_head */
msg_head->flags = op->flags;
msg_head->count = op->count;
msg_head->ival1 = op->ival1;
msg_head->ival2 = op->ival2;
msg_head->nframes = op->nframes;
bcm_send_to_user(op, msg_head, op->frames, 0);
return MHSIZ;
}
/*
* bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
*/
static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
int ifindex, struct sock *sk)
{
struct bcm_sock *bo = bcm_sk(sk);
struct bcm_op *op;
struct canfd_frame *cf;
unsigned int i;
int err;
/* we need a real device to send frames */
if (!ifindex)
return -ENODEV;
/* check nframes boundaries - we need at least one CAN frame */
if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
return -EINVAL;
/* check timeval limitations */
if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
return -EINVAL;
/* check the given can_id */
op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
if (op) {
/* update existing BCM operation */
/*
* Do we need more space for the CAN frames than currently
* allocated? -> This is a _really_ unusual use-case and
* therefore (complexity / locking) it is not supported.
*/
if (msg_head->nframes > op->nframes)
return -E2BIG;
/* update CAN frames content */
for (i = 0; i < msg_head->nframes; i++) {
cf = op->frames + op->cfsiz * i;
err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
if (op->flags & CAN_FD_FRAME) {
if (cf->len > 64)
err = -EINVAL;
} else {
if (cf->len > 8)
err = -EINVAL;
}
if (err < 0)
return err;
if (msg_head->flags & TX_CP_CAN_ID) {
/* copy can_id into frame */
cf->can_id = msg_head->can_id;
}
}
op->flags = msg_head->flags;
} else {
/* insert new BCM operation for the given can_id */
op = kzalloc(OPSIZ, GFP_KERNEL);
if (!op)
return -ENOMEM;
op->can_id = msg_head->can_id;
op->cfsiz = CFSIZ(msg_head->flags);
op->flags = msg_head->flags;
/* create array for CAN frames and copy the data */
if (msg_head->nframes > 1) {
op->frames = kmalloc_array(msg_head->nframes,
op->cfsiz,
GFP_KERNEL);
if (!op->frames) {
kfree(op);
return -ENOMEM;
}
} else
op->frames = &op->sframe;
for (i = 0; i < msg_head->nframes; i++) {
cf = op->frames + op->cfsiz * i;
err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
if (op->flags & CAN_FD_FRAME) {
if (cf->len > 64)
err = -EINVAL;
} else {
if (cf->len > 8)
err = -EINVAL;
}
if (err < 0) {
if (op->frames != &op->sframe)
kfree(op->frames);
kfree(op);
return err;
}
if (msg_head->flags & TX_CP_CAN_ID) {
/* copy can_id into frame */
cf->can_id = msg_head->can_id;
}
}
/* tx_ops never compare with previous received messages */
op->last_frames = NULL;
/* bcm_can_tx / bcm_tx_timeout_handler needs this */
op->sk = sk;
op->ifindex = ifindex;
/* initialize uninitialized (kzalloc) structure */
hrtimer_init(&op->timer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL_SOFT);
op->timer.function = bcm_tx_timeout_handler;
/* currently unused in tx_ops */
hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL_SOFT);
/* add this bcm_op to the list of the tx_ops */
list_add(&op->list, &bo->tx_ops);
} /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
if (op->nframes != msg_head->nframes) {
op->nframes = msg_head->nframes;
/* start multiple frame transmission with index 0 */
op->currframe = 0;
}
/* check flags */
if (op->flags & TX_RESET_MULTI_IDX) {
/* start multiple frame transmission with index 0 */
op->currframe = 0;
}
if (op->flags & SETTIMER) {
/* set timer values */
op->count = msg_head->count;
op->ival1 = msg_head->ival1;
op->ival2 = msg_head->ival2;
op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
/* disable an active timer due to zero values? */
if (!op->kt_ival1 && !op->kt_ival2)
hrtimer_cancel(&op->timer);
}
if (op->flags & STARTTIMER) {
hrtimer_cancel(&op->timer);
/* spec: send CAN frame when starting timer */
op->flags |= TX_ANNOUNCE;
}
if (op->flags & TX_ANNOUNCE) {
bcm_can_tx(op);
if (op->count)
op->count--;
}
if (op->flags & STARTTIMER)
bcm_tx_start_timer(op);
return msg_head->nframes * op->cfsiz + MHSIZ;
}
/*
* bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
*/
static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
int ifindex, struct sock *sk)
{
struct bcm_sock *bo = bcm_sk(sk);
struct bcm_op *op;
int do_rx_register;
int err = 0;
if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
/* be robust against wrong usage ... */
msg_head->flags |= RX_FILTER_ID;
/* ignore trailing garbage */
msg_head->nframes = 0;
}
/* the first element contains the mux-mask => MAX_NFRAMES + 1 */
if (msg_head->nframes > MAX_NFRAMES + 1)
return -EINVAL;
if ((msg_head->flags & RX_RTR_FRAME) &&
((msg_head->nframes != 1) ||
(!(msg_head->can_id & CAN_RTR_FLAG))))
return -EINVAL;
/* check timeval limitations */
if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
return -EINVAL;
/* check the given can_id */
op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
if (op) {
/* update existing BCM operation */
/*
* Do we need more space for the CAN frames than currently
* allocated? -> This is a _really_ unusual use-case and
* therefore (complexity / locking) it is not supported.
*/
if (msg_head->nframes > op->nframes)
return -E2BIG;
if (msg_head->nframes) {
/* update CAN frames content */
err = memcpy_from_msg(op->frames, msg,
msg_head->nframes * op->cfsiz);
if (err < 0)
return err;
/* clear last_frames to indicate 'nothing received' */
memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
}
op->nframes = msg_head->nframes;
op->flags = msg_head->flags;
/* Only an update -> do not call can_rx_register() */
do_rx_register = 0;
} else {
/* insert new BCM operation for the given can_id */
op = kzalloc(OPSIZ, GFP_KERNEL);
if (!op)
return -ENOMEM;
op->can_id = msg_head->can_id;
op->nframes = msg_head->nframes;
op->cfsiz = CFSIZ(msg_head->flags);
op->flags = msg_head->flags;
if (msg_head->nframes > 1) {
/* create array for CAN frames and copy the data */
op->frames = kmalloc_array(msg_head->nframes,
op->cfsiz,
GFP_KERNEL);
if (!op->frames) {
kfree(op);
return -ENOMEM;
}
/* create and init array for received CAN frames */
op->last_frames = kcalloc(msg_head->nframes,
op->cfsiz,
GFP_KERNEL);
if (!op->last_frames) {
kfree(op->frames);
kfree(op);
return -ENOMEM;
}
} else {
op->frames = &op->sframe;
op->last_frames = &op->last_sframe;
}
if (msg_head->nframes) {
err = memcpy_from_msg(op->frames, msg,
msg_head->nframes * op->cfsiz);
if (err < 0) {
if (op->frames != &op->sframe)
kfree(op->frames);
if (op->last_frames != &op->last_sframe)
kfree(op->last_frames);
kfree(op);
return err;
}
}
/* bcm_can_tx / bcm_tx_timeout_handler needs this */
op->sk = sk;
op->ifindex = ifindex;
/* ifindex for timeout events w/o previous frame reception */
op->rx_ifindex = ifindex;
/* initialize uninitialized (kzalloc) structure */
hrtimer_init(&op->timer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL_SOFT);
op->timer.function = bcm_rx_timeout_handler;
hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL_SOFT);
op->thrtimer.function = bcm_rx_thr_handler;
/* add this bcm_op to the list of the rx_ops */
list_add(&op->list, &bo->rx_ops);
/* call can_rx_register() */
do_rx_register = 1;
} /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
/* check flags */
if (op->flags & RX_RTR_FRAME) {
struct canfd_frame *frame0 = op->frames;
/* no timers in RTR-mode */
hrtimer_cancel(&op->thrtimer);
hrtimer_cancel(&op->timer);
/*
* funny feature in RX(!)_SETUP only for RTR-mode:
* copy can_id into frame BUT without RTR-flag to
* prevent a full-load-loopback-test ... ;-]
*/
if ((op->flags & TX_CP_CAN_ID) ||
(frame0->can_id == op->can_id))
frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
} else {
if (op->flags & SETTIMER) {
/* set timer value */
op->ival1 = msg_head->ival1;
op->ival2 = msg_head->ival2;
op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
/* disable an active timer due to zero value? */
if (!op->kt_ival1)
hrtimer_cancel(&op->timer);
/*
* In any case cancel the throttle timer, flush
* potentially blocked msgs and reset throttle handling
*/
op->kt_lastmsg = 0;
hrtimer_cancel(&op->thrtimer);
bcm_rx_thr_flush(op);
}
if ((op->flags & STARTTIMER) && op->kt_ival1)
hrtimer_start(&op->timer, op->kt_ival1,
HRTIMER_MODE_REL_SOFT);
}
/* now we can register for can_ids, if we added a new bcm_op */
if (do_rx_register) {
if (ifindex) {
struct net_device *dev;
dev = dev_get_by_index(sock_net(sk), ifindex);
if (dev) {
err = can_rx_register(sock_net(sk), dev,
op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op,
"bcm", sk);
op->rx_reg_dev = dev;
dev_put(dev);
}
} else
err = can_rx_register(sock_net(sk), NULL, op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op, "bcm", sk);
if (err) {
/* this bcm rx op is broken -> remove it */
list_del(&op->list);
bcm_remove_op(op);
return err;
}
}
return msg_head->nframes * op->cfsiz + MHSIZ;
}
/*
* bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
*/
static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
int cfsiz)
{
struct sk_buff *skb;
struct net_device *dev;
int err;
/* we need a real device to send frames */
if (!ifindex)
return -ENODEV;
skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
if (!skb)
return -ENOMEM;
can_skb_reserve(skb);
err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
if (err < 0) {
kfree_skb(skb);
return err;
}
dev = dev_get_by_index(sock_net(sk), ifindex);
if (!dev) {
kfree_skb(skb);
return -ENODEV;
}
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
skb->dev = dev;
can_skb_set_owner(skb, sk);
err = can_send(skb, 1); /* send with loopback */
dev_put(dev);
if (err)
return err;
return cfsiz + MHSIZ;
}
/*
* bcm_sendmsg - process BCM commands (opcodes) from the userspace
*/
static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
{
struct sock *sk = sock->sk;
struct bcm_sock *bo = bcm_sk(sk);
int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
struct bcm_msg_head msg_head;
int cfsiz;
int ret; /* read bytes or error codes as return value */
if (!bo->bound)
return -ENOTCONN;
/* check for valid message length from userspace */
if (size < MHSIZ)
return -EINVAL;
/* read message head information */
ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
if (ret < 0)
return ret;
cfsiz = CFSIZ(msg_head.flags);
if ((size - MHSIZ) % cfsiz)
return -EINVAL;
/* check for alternative ifindex for this bcm_op */
if (!ifindex && msg->msg_name) {
/* no bound device as default => check msg_name */
DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
if (msg->msg_namelen < BCM_MIN_NAMELEN)
return -EINVAL;
if (addr->can_family != AF_CAN)
return -EINVAL;
/* ifindex from sendto() */
ifindex = addr->can_ifindex;
if (ifindex) {
struct net_device *dev;
dev = dev_get_by_index(sock_net(sk), ifindex);
if (!dev)
return -ENODEV;
if (dev->type != ARPHRD_CAN) {
dev_put(dev);
return -ENODEV;
}
dev_put(dev);
}
}
lock_sock(sk);
switch (msg_head.opcode) {
case TX_SETUP:
ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
break;
case RX_SETUP:
ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
break;
case TX_DELETE:
if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
ret = MHSIZ;
else
ret = -EINVAL;
break;
case RX_DELETE:
if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
ret = MHSIZ;
else
ret = -EINVAL;
break;
case TX_READ:
/* reuse msg_head for the reply to TX_READ */
msg_head.opcode = TX_STATUS;
ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
break;
case RX_READ:
/* reuse msg_head for the reply to RX_READ */
msg_head.opcode = RX_STATUS;
ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
break;
case TX_SEND:
/* we need exactly one CAN frame behind the msg head */
if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
ret = -EINVAL;
else
ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
break;
default:
ret = -EINVAL;
break;
}
release_sock(sk);
return ret;
}
/*
* notification handler for netdevice status changes
*/
static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
struct sock *sk = &bo->sk;
struct bcm_op *op;
int notify_enodev = 0;
if (!net_eq(dev_net(dev), sock_net(sk)))
return NOTIFY_DONE;
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
switch (msg) {
case NETDEV_UNREGISTER:
lock_sock(sk);
/* remove device specific receive entries */
list_for_each_entry(op, &bo->rx_ops, list)
if (op->rx_reg_dev == dev)
bcm_rx_unreg(dev, op);
/* remove device reference, if this is our bound device */
if (bo->bound && bo->ifindex == dev->ifindex) {
bo->bound = 0;
bo->ifindex = 0;
notify_enodev = 1;
}
release_sock(sk);
if (notify_enodev) {
sk->sk_err = ENODEV;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
}
break;
case NETDEV_DOWN:
if (bo->bound && bo->ifindex == dev->ifindex) {
sk->sk_err = ENETDOWN;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_error_report(sk);
}
}
return NOTIFY_DONE;
}
/*
* initial settings for all BCM sockets to be set at socket creation time
*/
static int bcm_init(struct sock *sk)
{
struct bcm_sock *bo = bcm_sk(sk);
bo->bound = 0;
bo->ifindex = 0;
bo->dropped_usr_msgs = 0;
bo->bcm_proc_read = NULL;
INIT_LIST_HEAD(&bo->tx_ops);
INIT_LIST_HEAD(&bo->rx_ops);
/* set notifier */
bo->notifier.notifier_call = bcm_notifier;
register_netdevice_notifier(&bo->notifier);
return 0;
}
/*
* standard socket functions
*/
static int bcm_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct net *net;
struct bcm_sock *bo;
struct bcm_op *op, *next;
if (!sk)
return 0;
net = sock_net(sk);
bo = bcm_sk(sk);
/* remove bcm_ops, timer, rx_unregister(), etc. */
unregister_netdevice_notifier(&bo->notifier);
lock_sock(sk);
list_for_each_entry_safe(op, next, &bo->tx_ops, list)
bcm_remove_op(op);
list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
/*
* Don't care if we're bound or not (due to netdev problems)
* can_rx_unregister() is always a save thing to do here.
*/
if (op->ifindex) {
/*
* Only remove subscriptions that had not
* been removed due to NETDEV_UNREGISTER
* in bcm_notifier()
*/
if (op->rx_reg_dev) {
struct net_device *dev;
dev = dev_get_by_index(net, op->ifindex);
if (dev) {
bcm_rx_unreg(dev, op);
dev_put(dev);
}
}
} else
can_rx_unregister(net, NULL, op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op);
bcm_remove_op(op);
}
#if IS_ENABLED(CONFIG_PROC_FS)
/* remove procfs entry */
if (net->can.bcmproc_dir && bo->bcm_proc_read)
remove_proc_entry(bo->procname, net->can.bcmproc_dir);
#endif /* CONFIG_PROC_FS */
/* remove device reference */
if (bo->bound) {
bo->bound = 0;
bo->ifindex = 0;
}
sock_orphan(sk);
sock->sk = NULL;
release_sock(sk);
sock_put(sk);
return 0;
}
static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
int flags)
{
struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
struct sock *sk = sock->sk;
struct bcm_sock *bo = bcm_sk(sk);
struct net *net = sock_net(sk);
int ret = 0;
if (len < BCM_MIN_NAMELEN)
return -EINVAL;
lock_sock(sk);
if (bo->bound) {
ret = -EISCONN;
goto fail;
}
/* bind a device to this socket */
if (addr->can_ifindex) {
struct net_device *dev;
dev = dev_get_by_index(net, addr->can_ifindex);
if (!dev) {
ret = -ENODEV;
goto fail;
}
if (dev->type != ARPHRD_CAN) {
dev_put(dev);
ret = -ENODEV;
goto fail;
}
bo->ifindex = dev->ifindex;
dev_put(dev);
} else {
/* no interface reference for ifindex = 0 ('any' CAN device) */
bo->ifindex = 0;
}
#if IS_ENABLED(CONFIG_PROC_FS)
if (net->can.bcmproc_dir) {
/* unique socket address as filename */
sprintf(bo->procname, "%lu", sock_i_ino(sk));
bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
net->can.bcmproc_dir,
bcm_proc_show, sk);
if (!bo->bcm_proc_read) {
ret = -ENOMEM;
goto fail;
}
}
#endif /* CONFIG_PROC_FS */
bo->bound = 1;
fail:
release_sock(sk);
return ret;
}
static int bcm_recvmsg(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;
int err;
noblock = flags & MSG_DONTWAIT;
flags &= ~MSG_DONTWAIT;
skb = skb_recv_datagram(sk, flags, noblock, &error);
if (!skb)
return error;
if (skb->len < size)
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(BCM_MIN_NAMELEN);
msg->msg_namelen = BCM_MIN_NAMELEN;
memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
}
skb_free_datagram(sk, skb);
return size;
}
static int bcm_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 bcm_ops = {
.family = PF_CAN,
.release = bcm_release,
.bind = sock_no_bind,
.connect = bcm_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = sock_no_getname,
.poll = datagram_poll,
.ioctl = bcm_sock_no_ioctlcmd,
.gettstamp = sock_gettstamp,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.sendmsg = bcm_sendmsg,
.recvmsg = bcm_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static struct proto bcm_proto __read_mostly = {
.name = "CAN_BCM",
.owner = THIS_MODULE,
.obj_size = sizeof(struct bcm_sock),
.init = bcm_init,
};
static const struct can_proto bcm_can_proto = {
.type = SOCK_DGRAM,
.protocol = CAN_BCM,
.ops = &bcm_ops,
.prot = &bcm_proto,
};
static int canbcm_pernet_init(struct net *net)
{
#if IS_ENABLED(CONFIG_PROC_FS)
/* create /proc/net/can-bcm directory */
net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
#endif /* CONFIG_PROC_FS */
return 0;
}
static void canbcm_pernet_exit(struct net *net)
{
#if IS_ENABLED(CONFIG_PROC_FS)
/* remove /proc/net/can-bcm directory */
if (net->can.bcmproc_dir)
remove_proc_entry("can-bcm", net->proc_net);
#endif /* CONFIG_PROC_FS */
}
static struct pernet_operations canbcm_pernet_ops __read_mostly = {
.init = canbcm_pernet_init,
.exit = canbcm_pernet_exit,
};
static int __init bcm_module_init(void)
{
int err;
pr_info("can: broadcast manager protocol\n");
err = can_proto_register(&bcm_can_proto);
if (err < 0) {
printk(KERN_ERR "can: registration of bcm protocol failed\n");
return err;
}
register_pernet_subsys(&canbcm_pernet_ops);
return 0;
}
static void __exit bcm_module_exit(void)
{
can_proto_unregister(&bcm_can_proto);
unregister_pernet_subsys(&canbcm_pernet_ops);
}
module_init(bcm_module_init);
module_exit(bcm_module_exit);
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