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linux/net/can/bcm.c
Oliver Hartkopp ffd980f976 [CAN]: Add broadcast manager (bcm) protocol 
This patch adds the CAN broadcast manager (bcm) protocol.

Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:54:11 -08:00

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/*
* bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
*
* 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.
*
* Send feedback to <socketcan-users@lists.berlios.de>
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/proc_fs.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/bcm.h>
#include <net/sock.h>
#include <net/net_namespace.h>
/* use of last_frames[index].can_dlc */
#define RX_RECV 0x40 /* received data for this element */
#define RX_THR 0x80 /* element not been sent due to throttle feature */
#define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
/* get best masking value for can_rx_register() for a given single can_id */
#define REGMASK(id) ((id & CAN_RTR_FLAG) | ((id & CAN_EFF_FLAG) ? \
(CAN_EFF_MASK | CAN_EFF_FLAG) : CAN_SFF_MASK))
#define CAN_BCM_VERSION CAN_VERSION
static __initdata const char banner[] = KERN_INFO
"can: broadcast manager protocol (rev " CAN_BCM_VERSION ")\n";
MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
/* easy access to can_frame payload */
static inline u64 GET_U64(const struct can_frame *cp)
{
return *(u64 *)cp->data;
}
struct bcm_op {
struct list_head list;
int ifindex;
canid_t can_id;
int flags;
unsigned long j_ival1, j_ival2, j_lastmsg;
unsigned long frames_abs, frames_filtered;
struct timer_list timer, thrtimer;
struct timeval ival1, ival2;
ktime_t rx_stamp;
int rx_ifindex;
int count;
int nframes;
int currframe;
struct can_frame *frames;
struct can_frame *last_frames;
struct can_frame sframe;
struct can_frame last_sframe;
struct sock *sk;
struct net_device *rx_reg_dev;
};
static struct proc_dir_entry *proc_dir;
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 [9]; /* pointer printed in ASCII with \0 */
};
static inline struct bcm_sock *bcm_sk(const struct sock *sk)
{
return (struct bcm_sock *)sk;
}
#define CFSIZ sizeof(struct can_frame)
#define OPSIZ sizeof(struct bcm_op)
#define MHSIZ sizeof(struct bcm_msg_head)
/*
* rounded_tv2jif - calculate jiffies from timeval including optional up
* @tv: pointer to timeval
*
* Description:
* Unlike timeval_to_jiffies() provided in include/linux/jiffies.h, this
* function is intentionally more relaxed on precise timer ticks to get
* exact one jiffy for requested 1000us on a 1000HZ machine.
* This code is to be removed when upgrading to kernel hrtimer.
*
* Return:
* calculated jiffies (max: ULONG_MAX)
*/
static unsigned long rounded_tv2jif(const struct timeval *tv)
{
unsigned long sec = tv->tv_sec;
unsigned long usec = tv->tv_usec;
unsigned long jif;
if (sec > ULONG_MAX / HZ)
return ULONG_MAX;
/* round up to get at least the requested time */
usec += 1000000 / HZ - 1;
jif = usec / (1000000 / HZ);
if (sec * HZ > ULONG_MAX - jif)
return ULONG_MAX;
return jif + sec * HZ;
}
/*
* procfs functions
*/
static char *bcm_proc_getifname(int ifindex)
{
struct net_device *dev;
if (!ifindex)
return "any";
/* no usage counting */
dev = __dev_get_by_index(&init_net, ifindex);
if (dev)
return dev->name;
return "???";
}
static int bcm_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
int len = 0;
struct sock *sk = (struct sock *)data;
struct bcm_sock *bo = bcm_sk(sk);
struct bcm_op *op;
len += snprintf(page + len, PAGE_SIZE - len, ">>> socket %p",
sk->sk_socket);
len += snprintf(page + len, PAGE_SIZE - len, " / sk %p", sk);
len += snprintf(page + len, PAGE_SIZE - len, " / bo %p", bo);
len += snprintf(page + len, PAGE_SIZE - len, " / dropped %lu",
bo->dropped_usr_msgs);
len += snprintf(page + len, PAGE_SIZE - len, " / bound %s",
bcm_proc_getifname(bo->ifindex));
len += snprintf(page + len, PAGE_SIZE - len, " <<<\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;
len += snprintf(page + len, PAGE_SIZE - len,
"rx_op: %03X %-5s ",
op->can_id, bcm_proc_getifname(op->ifindex));
len += snprintf(page + len, PAGE_SIZE - len, "[%d]%c ",
op->nframes,
(op->flags & RX_CHECK_DLC)?'d':' ');
if (op->j_ival1)
len += snprintf(page + len, PAGE_SIZE - len,
"timeo=%ld ", op->j_ival1);
if (op->j_ival2)
len += snprintf(page + len, PAGE_SIZE - len,
"thr=%ld ", op->j_ival2);
len += snprintf(page + len, PAGE_SIZE - len,
"# recv %ld (%ld) => reduction: ",
op->frames_filtered, op->frames_abs);
reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
len += snprintf(page + len, PAGE_SIZE - len, "%s%ld%%\n",
(reduction == 100)?"near ":"", reduction);
if (len > PAGE_SIZE - 200) {
/* mark output cut off */
len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
break;
}
}
list_for_each_entry(op, &bo->tx_ops, list) {
len += snprintf(page + len, PAGE_SIZE - len,
"tx_op: %03X %s [%d] ",
op->can_id, bcm_proc_getifname(op->ifindex),
op->nframes);
if (op->j_ival1)
len += snprintf(page + len, PAGE_SIZE - len, "t1=%ld ",
op->j_ival1);
if (op->j_ival2)
len += snprintf(page + len, PAGE_SIZE - len, "t2=%ld ",
op->j_ival2);
len += snprintf(page + len, PAGE_SIZE - len, "# sent %ld\n",
op->frames_abs);
if (len > PAGE_SIZE - 100) {
/* mark output cut off */
len += snprintf(page + len, PAGE_SIZE - len, "(..)\n");
break;
}
}
len += snprintf(page + len, PAGE_SIZE - len, "\n");
*eof = 1;
return len;
}
/*
* 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 can_frame *cf = &op->frames[op->currframe];
/* no target device? => exit */
if (!op->ifindex)
return;
dev = dev_get_by_index(&init_net, op->ifindex);
if (!dev) {
/* RFC: should this bcm_op remove itself here? */
return;
}
skb = alloc_skb(CFSIZ, gfp_any());
if (!skb)
goto out;
memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
/* send with loopback */
skb->dev = dev;
skb->sk = 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 can_frame *frames, int has_timestamp)
{
struct sk_buff *skb;
struct can_frame *firstframe;
struct sockaddr_can *addr;
struct sock *sk = op->sk;
int datalen = head->nframes * CFSIZ;
int err;
skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
if (!skb)
return;
memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
if (head->nframes) {
/* can_frames starting here */
firstframe = (struct can_frame *) skb_tail_pointer(skb);
memcpy(skb_put(skb, datalen), frames, datalen);
/*
* the BCM uses the can_dlc-element of the can_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->can_dlc &= BCM_CAN_DLC_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.
*/
BUILD_BUG_ON(sizeof(skb->cb) < 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++;
}
}
/*
* bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
*/
static void bcm_tx_timeout_handler(unsigned long data)
{
struct bcm_op *op = (struct bcm_op *)data;
if (op->j_ival1 && (op->count > 0)) {
op->count--;
if (!op->count && (op->flags & TX_COUNTEVT)) {
struct bcm_msg_head msg_head;
/* 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);
}
}
if (op->j_ival1 && (op->count > 0)) {
/* send (next) frame */
bcm_can_tx(op);
mod_timer(&op->timer, jiffies + op->j_ival1);
} else {
if (op->j_ival2) {
/* send (next) frame */
bcm_can_tx(op);
mod_timer(&op->timer, jiffies + op->j_ival2);
}
}
return;
}
/*
* bcm_rx_changed - create a RX_CHANGED notification due to changed content
*/
static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
{
struct bcm_msg_head head;
op->j_lastmsg = jiffies;
/* update statistics */
op->frames_filtered++;
/* prevent statistics overflow */
if (op->frames_filtered > ULONG_MAX/100)
op->frames_filtered = op->frames_abs = 0;
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 can_frame *lastdata,
struct can_frame *rxdata)
{
unsigned long nexttx = op->j_lastmsg + op->j_ival2;
memcpy(lastdata, rxdata, CFSIZ);
/* mark as used */
lastdata->can_dlc |= RX_RECV;
/* throttle bcm_rx_changed ? */
if ((op->thrtimer.expires) ||
((op->j_ival2) && (nexttx > jiffies))) {
/* we are already waiting OR we have to start waiting */
/* mark as 'throttled' */
lastdata->can_dlc |= RX_THR;
if (!(op->thrtimer.expires)) {
/* start the timer only the first time */
mod_timer(&op->thrtimer, nexttx);
}
} else {
/* send RX_CHANGED to the user immediately */
bcm_rx_changed(op, rxdata);
}
}
/*
* 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, int index,
struct can_frame *rxdata)
{
/*
* no one uses the MSBs of can_dlc for comparation,
* so we use it here to detect the first time of reception
*/
if (!(op->last_frames[index].can_dlc & RX_RECV)) {
/* received data for the first time => send update to user */
bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
return;
}
/* do a real check in can_frame data section */
if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
(GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
return;
}
if (op->flags & RX_CHECK_DLC) {
/* do a real check in can_frame dlc */
if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
BCM_CAN_DLC_MASK)) {
bcm_rx_update_and_send(op, &op->last_frames[index],
rxdata);
return;
}
}
}
/*
* bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
*/
static void bcm_rx_starttimer(struct bcm_op *op)
{
if (op->flags & RX_NO_AUTOTIMER)
return;
if (op->j_ival1)
mod_timer(&op->timer, jiffies + op->j_ival1);
}
/*
* bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
*/
static void bcm_rx_timeout_handler(unsigned long data)
{
struct bcm_op *op = (struct bcm_op *)data;
struct bcm_msg_head msg_head;
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);
/* no restart of the timer is done here! */
/* 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 * CFSIZ);
}
}
/*
* bcm_rx_thr_handler - the time for blocked content updates is over now:
* Check for throttled data and send it to the userspace
*/
static void bcm_rx_thr_handler(unsigned long data)
{
struct bcm_op *op = (struct bcm_op *)data;
int i = 0;
/* mark disabled / consumed timer */
op->thrtimer.expires = 0;
if (op->nframes > 1) {
/* for MUX filter we start at index 1 */
for (i = 1; i < op->nframes; i++) {
if ((op->last_frames) &&
(op->last_frames[i].can_dlc & RX_THR)) {
op->last_frames[i].can_dlc &= ~RX_THR;
bcm_rx_changed(op, &op->last_frames[i]);
}
}
} else {
/* for RX_FILTER_ID and simple filter */
if (op->last_frames && (op->last_frames[0].can_dlc & RX_THR)) {
op->last_frames[0].can_dlc &= ~RX_THR;
bcm_rx_changed(op, &op->last_frames[0]);
}
}
}
/*
* bcm_rx_handler - handle a CAN frame receiption
*/
static void bcm_rx_handler(struct sk_buff *skb, void *data)
{
struct bcm_op *op = (struct bcm_op *)data;
struct can_frame rxframe;
int i;
/* disable timeout */
del_timer(&op->timer);
if (skb->len == sizeof(rxframe)) {
memcpy(&rxframe, skb->data, sizeof(rxframe));
/* save rx timestamp */
op->rx_stamp = skb->tstamp;
/* save originator for recvfrom() */
op->rx_ifindex = skb->dev->ifindex;
/* update statistics */
op->frames_abs++;
kfree_skb(skb);
} else {
kfree_skb(skb);
return;
}
if (op->can_id != rxframe.can_id)
return;
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[0], &rxframe);
bcm_rx_starttimer(op);
return;
}
if (op->nframes == 1) {
/* simple compare with index 0 */
bcm_rx_cmp_to_index(op, 0, &rxframe);
bcm_rx_starttimer(op);
return;
}
if (op->nframes > 1) {
/*
* multiplex compare
*
* find the first multiplex mask that fits.
* Remark: The MUX-mask is stored in index 0
*/
for (i = 1; i < op->nframes; i++) {
if ((GET_U64(&op->frames[0]) & GET_U64(&rxframe)) ==
(GET_U64(&op->frames[0]) &
GET_U64(&op->frames[i]))) {
bcm_rx_cmp_to_index(op, i, &rxframe);
break;
}
}
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, canid_t can_id,
int ifindex)
{
struct bcm_op *op;
list_for_each_entry(op, ops, list) {
if ((op->can_id == can_id) && (op->ifindex == ifindex))
return op;
}
return NULL;
}
static void bcm_remove_op(struct bcm_op *op)
{
del_timer(&op->timer);
del_timer(&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);
return;
}
static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
{
if (op->rx_reg_dev == dev) {
can_rx_unregister(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, canid_t can_id, int ifindex)
{
struct bcm_op *op, *n;
list_for_each_entry_safe(op, n, ops, list) {
if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
/*
* 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(&init_net,
op->ifindex);
if (dev) {
bcm_rx_unreg(dev, op);
dev_put(dev);
}
}
} else
can_rx_unregister(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, canid_t can_id, int ifindex)
{
struct bcm_op *op, *n;
list_for_each_entry_safe(op, n, ops, list) {
if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
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->can_id, 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;
int i, err;
/* we need a real device to send frames */
if (!ifindex)
return -ENODEV;
/* we need at least one can_frame */
if (msg_head->nframes < 1)
return -EINVAL;
/* check the given can_id */
op = bcm_find_op(&bo->tx_ops, msg_head->can_id, 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++) {
err = memcpy_fromiovec((u8 *)&op->frames[i],
msg->msg_iov, CFSIZ);
if (err < 0)
return err;
if (msg_head->flags & TX_CP_CAN_ID) {
/* copy can_id into frame */
op->frames[i].can_id = msg_head->can_id;
}
}
} 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;
/* create array for can_frames and copy the data */
if (msg_head->nframes > 1) {
op->frames = kmalloc(msg_head->nframes * CFSIZ,
GFP_KERNEL);
if (!op->frames) {
kfree(op);
return -ENOMEM;
}
} else
op->frames = &op->sframe;
for (i = 0; i < msg_head->nframes; i++) {
err = memcpy_fromiovec((u8 *)&op->frames[i],
msg->msg_iov, CFSIZ);
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 */
op->frames[i].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 */
setup_timer(&op->timer, bcm_tx_timeout_handler,
(unsigned long)op);
/* currently unused in tx_ops */
init_timer(&op->thrtimer);
/* 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 */
op->flags = msg_head->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->j_ival1 = rounded_tv2jif(&msg_head->ival1);
op->j_ival2 = rounded_tv2jif(&msg_head->ival2);
/* disable an active timer due to zero values? */
if (!op->j_ival1 && !op->j_ival2)
del_timer(&op->timer);
}
if ((op->flags & STARTTIMER) &&
((op->j_ival1 && op->count) || op->j_ival2)) {
/* spec: send can_frame when starting timer */
op->flags |= TX_ANNOUNCE;
if (op->j_ival1 && (op->count > 0)) {
/* op->count-- is done in bcm_tx_timeout_handler */
mod_timer(&op->timer, jiffies + op->j_ival1);
} else
mod_timer(&op->timer, jiffies + op->j_ival2);
}
if (op->flags & TX_ANNOUNCE)
bcm_can_tx(op);
return msg_head->nframes * 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;
}
if ((msg_head->flags & RX_RTR_FRAME) &&
((msg_head->nframes != 1) ||
(!(msg_head->can_id & CAN_RTR_FLAG))))
return -EINVAL;
/* check the given can_id */
op = bcm_find_op(&bo->rx_ops, msg_head->can_id, 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_fromiovec((u8 *)op->frames,
msg->msg_iov,
msg_head->nframes * CFSIZ);
if (err < 0)
return err;
/* clear last_frames to indicate 'nothing received' */
memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
}
op->nframes = msg_head->nframes;
/* 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;
if (msg_head->nframes > 1) {
/* create array for can_frames and copy the data */
op->frames = kmalloc(msg_head->nframes * CFSIZ,
GFP_KERNEL);
if (!op->frames) {
kfree(op);
return -ENOMEM;
}
/* create and init array for received can_frames */
op->last_frames = kzalloc(msg_head->nframes * 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_fromiovec((u8 *)op->frames, msg->msg_iov,
msg_head->nframes * 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;
/* initialize uninitialized (kzalloc) structure */
setup_timer(&op->timer, bcm_rx_timeout_handler,
(unsigned long)op);
/* init throttle timer for RX_CHANGED */
setup_timer(&op->thrtimer, bcm_rx_thr_handler,
(unsigned long)op);
/* mark disabled timer */
op->thrtimer.expires = 0;
/* 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 */
op->flags = msg_head->flags;
if (op->flags & RX_RTR_FRAME) {
/* no timers in RTR-mode */
del_timer(&op->thrtimer);
del_timer(&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) ||
(op->frames[0].can_id == op->can_id))
op->frames[0].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->j_ival1 = rounded_tv2jif(&msg_head->ival1);
op->j_ival2 = rounded_tv2jif(&msg_head->ival2);
/* disable an active timer due to zero value? */
if (!op->j_ival1)
del_timer(&op->timer);
/* free currently blocked msgs ? */
if (op->thrtimer.expires) {
/* send blocked msgs hereafter */
mod_timer(&op->thrtimer, jiffies + 2);
}
/*
* if (op->j_ival2) is zero, no (new) throttling
* will happen. For details see functions
* bcm_rx_update_and_send() and bcm_rx_thr_handler()
*/
}
if ((op->flags & STARTTIMER) && op->j_ival1)
mod_timer(&op->timer, jiffies + op->j_ival1);
}
/* 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(&init_net, ifindex);
if (dev) {
err = can_rx_register(dev, op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op,
"bcm");
op->rx_reg_dev = dev;
dev_put(dev);
}
} else
err = can_rx_register(NULL, op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op, "bcm");
if (err) {
/* this bcm rx op is broken -> remove it */
list_del(&op->list);
bcm_remove_op(op);
return err;
}
}
return msg_head->nframes * 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)
{
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, GFP_KERNEL);
if (!skb)
return -ENOMEM;
err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
if (err < 0) {
kfree_skb(skb);
return err;
}
dev = dev_get_by_index(&init_net, ifindex);
if (!dev) {
kfree_skb(skb);
return -ENODEV;
}
skb->dev = dev;
skb->sk = sk;
can_send(skb, 1); /* send with loopback */
dev_put(dev);
return CFSIZ + MHSIZ;
}
/*
* bcm_sendmsg - process BCM commands (opcodes) from the userspace
*/
static int bcm_sendmsg(struct kiocb *iocb, 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 ret; /* read bytes or error codes as return value */
if (!bo->bound)
return -ENOTCONN;
/* check for alternative ifindex for this bcm_op */
if (!ifindex && msg->msg_name) {
/* no bound device as default => check msg_name */
struct sockaddr_can *addr =
(struct sockaddr_can *)msg->msg_name;
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(&init_net, ifindex);
if (!dev)
return -ENODEV;
if (dev->type != ARPHRD_CAN) {
dev_put(dev);
return -ENODEV;
}
dev_put(dev);
}
}
/* read message head information */
ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
if (ret < 0)
return ret;
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.can_id, ifindex))
ret = MHSIZ;
else
ret = -EINVAL;
break;
case RX_DELETE:
if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, 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 at least one can_frame */
if (msg_head.nframes < 1)
ret = -EINVAL;
else
ret = bcm_tx_send(msg, ifindex, sk);
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 *data)
{
struct net_device *dev = (struct net_device *)data;
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 (dev->nd_net != &init_net)
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 bcm_sock *bo = bcm_sk(sk);
struct bcm_op *op, *next;
/* 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(&init_net, op->ifindex);
if (dev) {
bcm_rx_unreg(dev, op);
dev_put(dev);
}
}
} else
can_rx_unregister(NULL, op->can_id,
REGMASK(op->can_id),
bcm_rx_handler, op);
bcm_remove_op(op);
}
/* remove procfs entry */
if (proc_dir && bo->bcm_proc_read)
remove_proc_entry(bo->procname, proc_dir);
/* remove device reference */
if (bo->bound) {
bo->bound = 0;
bo->ifindex = 0;
}
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);
if (bo->bound)
return -EISCONN;
/* bind a device to this socket */
if (addr->can_ifindex) {
struct net_device *dev;
dev = dev_get_by_index(&init_net, addr->can_ifindex);
if (!dev)
return -ENODEV;
if (dev->type != ARPHRD_CAN) {
dev_put(dev);
return -ENODEV;
}
bo->ifindex = dev->ifindex;
dev_put(dev);
} else {
/* no interface reference for ifindex = 0 ('any' CAN device) */
bo->ifindex = 0;
}
bo->bound = 1;
if (proc_dir) {
/* unique socket address as filename */
sprintf(bo->procname, "%p", sock);
bo->bcm_proc_read = create_proc_read_entry(bo->procname, 0644,
proc_dir,
bcm_read_proc, sk);
}
return 0;
}
static int bcm_recvmsg(struct kiocb *iocb, 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_toiovec(msg->msg_iov, skb->data, size);
if (err < 0) {
skb_free_datagram(sk, skb);
return err;
}
sock_recv_timestamp(msg, sk, skb);
if (msg->msg_name) {
msg->msg_namelen = sizeof(struct sockaddr_can);
memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
}
skb_free_datagram(sk, skb);
return size;
}
static struct proto_ops bcm_ops __read_mostly = {
.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 = NULL, /* use can_ioctl() from af_can.c */
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = sock_no_setsockopt,
.getsockopt = sock_no_getsockopt,
.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 struct can_proto bcm_can_proto __read_mostly = {
.type = SOCK_DGRAM,
.protocol = CAN_BCM,
.capability = -1,
.ops = &bcm_ops,
.prot = &bcm_proto,
};
static int __init bcm_module_init(void)
{
int err;
printk(banner);
err = can_proto_register(&bcm_can_proto);
if (err < 0) {
printk(KERN_ERR "can: registration of bcm protocol failed\n");
return err;
}
/* create /proc/net/can-bcm directory */
proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
if (proc_dir)
proc_dir->owner = THIS_MODULE;
return 0;
}
static void __exit bcm_module_exit(void)
{
can_proto_unregister(&bcm_can_proto);
if (proc_dir)
proc_net_remove(&init_net, "can-bcm");
}
module_init(bcm_module_init);
module_exit(bcm_module_exit);
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