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Linux/net/can/bcm.c

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  1 /*
  2  * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
  3  *
  4  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
  5  * All rights reserved.
  6  *
  7  * Redistribution and use in source and binary forms, with or without
  8  * modification, are permitted provided that the following conditions
  9  * are met:
 10  * 1. Redistributions of source code must retain the above copyright
 11  *    notice, this list of conditions and the following disclaimer.
 12  * 2. Redistributions in binary form must reproduce the above copyright
 13  *    notice, this list of conditions and the following disclaimer in the
 14  *    documentation and/or other materials provided with the distribution.
 15  * 3. Neither the name of Volkswagen nor the names of its contributors
 16  *    may be used to endorse or promote products derived from this software
 17  *    without specific prior written permission.
 18  *
 19  * Alternatively, provided that this notice is retained in full, this
 20  * software may be distributed under the terms of the GNU General
 21  * Public License ("GPL") version 2, in which case the provisions of the
 22  * GPL apply INSTEAD OF those given above.
 23  *
 24  * The provided data structures and external interfaces from this code
 25  * are not restricted to be used by modules with a GPL compatible license.
 26  *
 27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 38  * DAMAGE.
 39  *
 40  * Send feedback to <socketcan-users@lists.berlios.de>
 41  *
 42  */
 43 
 44 #include <linux/module.h>
 45 #include <linux/init.h>
 46 #include <linux/hrtimer.h>
 47 #include <linux/list.h>
 48 #include <linux/proc_fs.h>
 49 #include <linux/seq_file.h>
 50 #include <linux/uio.h>
 51 #include <linux/net.h>
 52 #include <linux/netdevice.h>
 53 #include <linux/socket.h>
 54 #include <linux/if_arp.h>
 55 #include <linux/skbuff.h>
 56 #include <linux/can.h>
 57 #include <linux/can/core.h>
 58 #include <linux/can/bcm.h>
 59 #include <linux/slab.h>
 60 #include <net/sock.h>
 61 #include <net/net_namespace.h>
 62 
 63 /*
 64  * To send multiple CAN frame content within TX_SETUP or to filter
 65  * CAN messages with multiplex index within RX_SETUP, the number of
 66  * different filters is limited to 256 due to the one byte index value.
 67  */
 68 #define MAX_NFRAMES 256
 69 
 70 /* use of last_frames[index].can_dlc */
 71 #define RX_RECV    0x40 /* received data for this element */
 72 #define RX_THR     0x80 /* element not been sent due to throttle feature */
 73 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
 74 
 75 /* get best masking value for can_rx_register() for a given single can_id */
 76 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
 77                      (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
 78                      (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
 79 
 80 #define CAN_BCM_VERSION CAN_VERSION
 81 static __initdata const char banner[] = KERN_INFO
 82         "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
 83 
 84 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
 85 MODULE_LICENSE("Dual BSD/GPL");
 86 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
 87 MODULE_ALIAS("can-proto-2");
 88 
 89 /* easy access to can_frame payload */
 90 static inline u64 GET_U64(const struct can_frame *cp)
 91 {
 92         return *(u64 *)cp->data;
 93 }
 94 
 95 struct bcm_op {
 96         struct list_head list;
 97         int ifindex;
 98         canid_t can_id;
 99         u32 flags;
100         unsigned long frames_abs, frames_filtered;
101         struct timeval ival1, ival2;
102         struct hrtimer timer, thrtimer;
103         struct tasklet_struct tsklet, thrtsklet;
104         ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
105         int rx_ifindex;
106         u32 count;
107         u32 nframes;
108         u32 currframe;
109         struct can_frame *frames;
110         struct can_frame *last_frames;
111         struct can_frame sframe;
112         struct can_frame last_sframe;
113         struct sock *sk;
114         struct net_device *rx_reg_dev;
115 };
116 
117 static struct proc_dir_entry *proc_dir;
118 
119 struct bcm_sock {
120         struct sock sk;
121         int bound;
122         int ifindex;
123         struct notifier_block notifier;
124         struct list_head rx_ops;
125         struct list_head tx_ops;
126         unsigned long dropped_usr_msgs;
127         struct proc_dir_entry *bcm_proc_read;
128         char procname [32]; /* inode number in decimal with \0 */
129 };
130 
131 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
132 {
133         return (struct bcm_sock *)sk;
134 }
135 
136 #define CFSIZ sizeof(struct can_frame)
137 #define OPSIZ sizeof(struct bcm_op)
138 #define MHSIZ sizeof(struct bcm_msg_head)
139 
140 /*
141  * procfs functions
142  */
143 static char *bcm_proc_getifname(char *result, int ifindex)
144 {
145         struct net_device *dev;
146 
147         if (!ifindex)
148                 return "any";
149 
150         rcu_read_lock();
151         dev = dev_get_by_index_rcu(&init_net, ifindex);
152         if (dev)
153                 strcpy(result, dev->name);
154         else
155                 strcpy(result, "???");
156         rcu_read_unlock();
157 
158         return result;
159 }
160 
161 static int bcm_proc_show(struct seq_file *m, void *v)
162 {
163         char ifname[IFNAMSIZ];
164         struct sock *sk = (struct sock *)m->private;
165         struct bcm_sock *bo = bcm_sk(sk);
166         struct bcm_op *op;
167 
168         seq_printf(m, ">>> socket %pK", sk->sk_socket);
169         seq_printf(m, " / sk %pK", sk);
170         seq_printf(m, " / bo %pK", bo);
171         seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
172         seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
173         seq_printf(m, " <<<\n");
174 
175         list_for_each_entry(op, &bo->rx_ops, list) {
176 
177                 unsigned long reduction;
178 
179                 /* print only active entries & prevent division by zero */
180                 if (!op->frames_abs)
181                         continue;
182 
183                 seq_printf(m, "rx_op: %03X %-5s ",
184                                 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
185                 seq_printf(m, "[%u]%c ", op->nframes,
186                                 (op->flags & RX_CHECK_DLC)?'d':' ');
187                 if (op->kt_ival1.tv64)
188                         seq_printf(m, "timeo=%lld ",
189                                         (long long)
190                                         ktime_to_us(op->kt_ival1));
191 
192                 if (op->kt_ival2.tv64)
193                         seq_printf(m, "thr=%lld ",
194                                         (long long)
195                                         ktime_to_us(op->kt_ival2));
196 
197                 seq_printf(m, "# recv %ld (%ld) => reduction: ",
198                                 op->frames_filtered, op->frames_abs);
199 
200                 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
201 
202                 seq_printf(m, "%s%ld%%\n",
203                                 (reduction == 100)?"near ":"", reduction);
204         }
205 
206         list_for_each_entry(op, &bo->tx_ops, list) {
207 
208                 seq_printf(m, "tx_op: %03X %s [%u] ",
209                                 op->can_id,
210                                 bcm_proc_getifname(ifname, op->ifindex),
211                                 op->nframes);
212 
213                 if (op->kt_ival1.tv64)
214                         seq_printf(m, "t1=%lld ",
215                                         (long long) ktime_to_us(op->kt_ival1));
216 
217                 if (op->kt_ival2.tv64)
218                         seq_printf(m, "t2=%lld ",
219                                         (long long) ktime_to_us(op->kt_ival2));
220 
221                 seq_printf(m, "# sent %ld\n", op->frames_abs);
222         }
223         seq_putc(m, '\n');
224         return 0;
225 }
226 
227 static int bcm_proc_open(struct inode *inode, struct file *file)
228 {
229         return single_open(file, bcm_proc_show, PDE(inode)->data);
230 }
231 
232 static const struct file_operations bcm_proc_fops = {
233         .owner          = THIS_MODULE,
234         .open           = bcm_proc_open,
235         .read           = seq_read,
236         .llseek         = seq_lseek,
237         .release        = single_release,
238 };
239 
240 /*
241  * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
242  *              of the given bcm tx op
243  */
244 static void bcm_can_tx(struct bcm_op *op)
245 {
246         struct sk_buff *skb;
247         struct net_device *dev;
248         struct can_frame *cf = &op->frames[op->currframe];
249 
250         /* no target device? => exit */
251         if (!op->ifindex)
252                 return;
253 
254         dev = dev_get_by_index(&init_net, op->ifindex);
255         if (!dev) {
256                 /* RFC: should this bcm_op remove itself here? */
257                 return;
258         }
259 
260         skb = alloc_skb(CFSIZ, gfp_any());
261         if (!skb)
262                 goto out;
263 
264         memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
265 
266         /* send with loopback */
267         skb->dev = dev;
268         skb->sk = op->sk;
269         can_send(skb, 1);
270 
271         /* update statistics */
272         op->currframe++;
273         op->frames_abs++;
274 
275         /* reached last frame? */
276         if (op->currframe >= op->nframes)
277                 op->currframe = 0;
278  out:
279         dev_put(dev);
280 }
281 
282 /*
283  * bcm_send_to_user - send a BCM message to the userspace
284  *                    (consisting of bcm_msg_head + x CAN frames)
285  */
286 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
287                              struct can_frame *frames, int has_timestamp)
288 {
289         struct sk_buff *skb;
290         struct can_frame *firstframe;
291         struct sockaddr_can *addr;
292         struct sock *sk = op->sk;
293         unsigned int datalen = head->nframes * CFSIZ;
294         int err;
295 
296         skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
297         if (!skb)
298                 return;
299 
300         memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
301 
302         if (head->nframes) {
303                 /* can_frames starting here */
304                 firstframe = (struct can_frame *)skb_tail_pointer(skb);
305 
306                 memcpy(skb_put(skb, datalen), frames, datalen);
307 
308                 /*
309                  * the BCM uses the can_dlc-element of the can_frame
310                  * structure for internal purposes. This is only
311                  * relevant for updates that are generated by the
312                  * BCM, where nframes is 1
313                  */
314                 if (head->nframes == 1)
315                         firstframe->can_dlc &= BCM_CAN_DLC_MASK;
316         }
317 
318         if (has_timestamp) {
319                 /* restore rx timestamp */
320                 skb->tstamp = op->rx_stamp;
321         }
322 
323         /*
324          *  Put the datagram to the queue so that bcm_recvmsg() can
325          *  get it from there.  We need to pass the interface index to
326          *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
327          *  containing the interface index.
328          */
329 
330         BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
331         addr = (struct sockaddr_can *)skb->cb;
332         memset(addr, 0, sizeof(*addr));
333         addr->can_family  = AF_CAN;
334         addr->can_ifindex = op->rx_ifindex;
335 
336         err = sock_queue_rcv_skb(sk, skb);
337         if (err < 0) {
338                 struct bcm_sock *bo = bcm_sk(sk);
339 
340                 kfree_skb(skb);
341                 /* don't care about overflows in this statistic */
342                 bo->dropped_usr_msgs++;
343         }
344 }
345 
346 static void bcm_tx_start_timer(struct bcm_op *op)
347 {
348         if (op->kt_ival1.tv64 && op->count)
349                 hrtimer_start(&op->timer,
350                               ktime_add(ktime_get(), op->kt_ival1),
351                               HRTIMER_MODE_ABS);
352         else if (op->kt_ival2.tv64)
353                 hrtimer_start(&op->timer,
354                               ktime_add(ktime_get(), op->kt_ival2),
355                               HRTIMER_MODE_ABS);
356 }
357 
358 static void bcm_tx_timeout_tsklet(unsigned long data)
359 {
360         struct bcm_op *op = (struct bcm_op *)data;
361         struct bcm_msg_head msg_head;
362 
363         if (op->kt_ival1.tv64 && (op->count > 0)) {
364 
365                 op->count--;
366                 if (!op->count && (op->flags & TX_COUNTEVT)) {
367 
368                         /* create notification to user */
369                         msg_head.opcode  = TX_EXPIRED;
370                         msg_head.flags   = op->flags;
371                         msg_head.count   = op->count;
372                         msg_head.ival1   = op->ival1;
373                         msg_head.ival2   = op->ival2;
374                         msg_head.can_id  = op->can_id;
375                         msg_head.nframes = 0;
376 
377                         bcm_send_to_user(op, &msg_head, NULL, 0);
378                 }
379                 bcm_can_tx(op);
380 
381         } else if (op->kt_ival2.tv64)
382                 bcm_can_tx(op);
383 
384         bcm_tx_start_timer(op);
385 }
386 
387 /*
388  * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
389  */
390 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
391 {
392         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
393 
394         tasklet_schedule(&op->tsklet);
395 
396         return HRTIMER_NORESTART;
397 }
398 
399 /*
400  * bcm_rx_changed - create a RX_CHANGED notification due to changed content
401  */
402 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
403 {
404         struct bcm_msg_head head;
405 
406         /* update statistics */
407         op->frames_filtered++;
408 
409         /* prevent statistics overflow */
410         if (op->frames_filtered > ULONG_MAX/100)
411                 op->frames_filtered = op->frames_abs = 0;
412 
413         /* this element is not throttled anymore */
414         data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
415 
416         head.opcode  = RX_CHANGED;
417         head.flags   = op->flags;
418         head.count   = op->count;
419         head.ival1   = op->ival1;
420         head.ival2   = op->ival2;
421         head.can_id  = op->can_id;
422         head.nframes = 1;
423 
424         bcm_send_to_user(op, &head, data, 1);
425 }
426 
427 /*
428  * bcm_rx_update_and_send - process a detected relevant receive content change
429  *                          1. update the last received data
430  *                          2. send a notification to the user (if possible)
431  */
432 static void bcm_rx_update_and_send(struct bcm_op *op,
433                                    struct can_frame *lastdata,
434                                    const struct can_frame *rxdata)
435 {
436         memcpy(lastdata, rxdata, CFSIZ);
437 
438         /* mark as used and throttled by default */
439         lastdata->can_dlc |= (RX_RECV|RX_THR);
440 
441         /* throtteling mode inactive ? */
442         if (!op->kt_ival2.tv64) {
443                 /* send RX_CHANGED to the user immediately */
444                 bcm_rx_changed(op, lastdata);
445                 return;
446         }
447 
448         /* with active throttling timer we are just done here */
449         if (hrtimer_active(&op->thrtimer))
450                 return;
451 
452         /* first receiption with enabled throttling mode */
453         if (!op->kt_lastmsg.tv64)
454                 goto rx_changed_settime;
455 
456         /* got a second frame inside a potential throttle period? */
457         if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
458             ktime_to_us(op->kt_ival2)) {
459                 /* do not send the saved data - only start throttle timer */
460                 hrtimer_start(&op->thrtimer,
461                               ktime_add(op->kt_lastmsg, op->kt_ival2),
462                               HRTIMER_MODE_ABS);
463                 return;
464         }
465 
466         /* the gap was that big, that throttling was not needed here */
467 rx_changed_settime:
468         bcm_rx_changed(op, lastdata);
469         op->kt_lastmsg = ktime_get();
470 }
471 
472 /*
473  * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
474  *                       received data stored in op->last_frames[]
475  */
476 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
477                                 const struct can_frame *rxdata)
478 {
479         /*
480          * no one uses the MSBs of can_dlc for comparation,
481          * so we use it here to detect the first time of reception
482          */
483 
484         if (!(op->last_frames[index].can_dlc & RX_RECV)) {
485                 /* received data for the first time => send update to user */
486                 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
487                 return;
488         }
489 
490         /* do a real check in can_frame data section */
491 
492         if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
493             (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
494                 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
495                 return;
496         }
497 
498         if (op->flags & RX_CHECK_DLC) {
499                 /* do a real check in can_frame dlc */
500                 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
501                                         BCM_CAN_DLC_MASK)) {
502                         bcm_rx_update_and_send(op, &op->last_frames[index],
503                                                rxdata);
504                         return;
505                 }
506         }
507 }
508 
509 /*
510  * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
511  */
512 static void bcm_rx_starttimer(struct bcm_op *op)
513 {
514         if (op->flags & RX_NO_AUTOTIMER)
515                 return;
516 
517         if (op->kt_ival1.tv64)
518                 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
519 }
520 
521 static void bcm_rx_timeout_tsklet(unsigned long data)
522 {
523         struct bcm_op *op = (struct bcm_op *)data;
524         struct bcm_msg_head msg_head;
525 
526         /* create notification to user */
527         msg_head.opcode  = RX_TIMEOUT;
528         msg_head.flags   = op->flags;
529         msg_head.count   = op->count;
530         msg_head.ival1   = op->ival1;
531         msg_head.ival2   = op->ival2;
532         msg_head.can_id  = op->can_id;
533         msg_head.nframes = 0;
534 
535         bcm_send_to_user(op, &msg_head, NULL, 0);
536 }
537 
538 /*
539  * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
540  */
541 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
542 {
543         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
544 
545         /* schedule before NET_RX_SOFTIRQ */
546         tasklet_hi_schedule(&op->tsklet);
547 
548         /* no restart of the timer is done here! */
549 
550         /* if user wants to be informed, when cyclic CAN-Messages come back */
551         if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
552                 /* clear received can_frames to indicate 'nothing received' */
553                 memset(op->last_frames, 0, op->nframes * CFSIZ);
554         }
555 
556         return HRTIMER_NORESTART;
557 }
558 
559 /*
560  * bcm_rx_do_flush - helper for bcm_rx_thr_flush
561  */
562 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
563                                   unsigned int index)
564 {
565         if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
566                 if (update)
567                         bcm_rx_changed(op, &op->last_frames[index]);
568                 return 1;
569         }
570         return 0;
571 }
572 
573 /*
574  * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
575  *
576  * update == 0 : just check if throttled data is available  (any irq context)
577  * update == 1 : check and send throttled data to userspace (soft_irq context)
578  */
579 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
580 {
581         int updated = 0;
582 
583         if (op->nframes > 1) {
584                 unsigned int i;
585 
586                 /* for MUX filter we start at index 1 */
587                 for (i = 1; i < op->nframes; i++)
588                         updated += bcm_rx_do_flush(op, update, i);
589 
590         } else {
591                 /* for RX_FILTER_ID and simple filter */
592                 updated += bcm_rx_do_flush(op, update, 0);
593         }
594 
595         return updated;
596 }
597 
598 static void bcm_rx_thr_tsklet(unsigned long data)
599 {
600         struct bcm_op *op = (struct bcm_op *)data;
601 
602         /* push the changed data to the userspace */
603         bcm_rx_thr_flush(op, 1);
604 }
605 
606 /*
607  * bcm_rx_thr_handler - the time for blocked content updates is over now:
608  *                      Check for throttled data and send it to the userspace
609  */
610 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
611 {
612         struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
613 
614         tasklet_schedule(&op->thrtsklet);
615 
616         if (bcm_rx_thr_flush(op, 0)) {
617                 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
618                 return HRTIMER_RESTART;
619         } else {
620                 /* rearm throttle handling */
621                 op->kt_lastmsg = ktime_set(0, 0);
622                 return HRTIMER_NORESTART;
623         }
624 }
625 
626 /*
627  * bcm_rx_handler - handle a CAN frame receiption
628  */
629 static void bcm_rx_handler(struct sk_buff *skb, void *data)
630 {
631         struct bcm_op *op = (struct bcm_op *)data;
632         const struct can_frame *rxframe = (struct can_frame *)skb->data;
633         unsigned int i;
634 
635         /* disable timeout */
636         hrtimer_cancel(&op->timer);
637 
638         if (op->can_id != rxframe->can_id)
639                 return;
640 
641         /* save rx timestamp */
642         op->rx_stamp = skb->tstamp;
643         /* save originator for recvfrom() */
644         op->rx_ifindex = skb->dev->ifindex;
645         /* update statistics */
646         op->frames_abs++;
647 
648         if (op->flags & RX_RTR_FRAME) {
649                 /* send reply for RTR-request (placed in op->frames[0]) */
650                 bcm_can_tx(op);
651                 return;
652         }
653 
654         if (op->flags & RX_FILTER_ID) {
655                 /* the easiest case */
656                 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
657                 goto rx_starttimer;
658         }
659 
660         if (op->nframes == 1) {
661                 /* simple compare with index 0 */
662                 bcm_rx_cmp_to_index(op, 0, rxframe);
663                 goto rx_starttimer;
664         }
665 
666         if (op->nframes > 1) {
667                 /*
668                  * multiplex compare
669                  *
670                  * find the first multiplex mask that fits.
671                  * Remark: The MUX-mask is stored in index 0
672                  */
673 
674                 for (i = 1; i < op->nframes; i++) {
675                         if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
676                             (GET_U64(&op->frames[0]) &
677                              GET_U64(&op->frames[i]))) {
678                                 bcm_rx_cmp_to_index(op, i, rxframe);
679                                 break;
680                         }
681                 }
682         }
683 
684 rx_starttimer:
685         bcm_rx_starttimer(op);
686 }
687 
688 /*
689  * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
690  */
691 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
692                                   int ifindex)
693 {
694         struct bcm_op *op;
695 
696         list_for_each_entry(op, ops, list) {
697                 if ((op->can_id == can_id) && (op->ifindex == ifindex))
698                         return op;
699         }
700 
701         return NULL;
702 }
703 
704 static void bcm_remove_op(struct bcm_op *op)
705 {
706         hrtimer_cancel(&op->timer);
707         hrtimer_cancel(&op->thrtimer);
708 
709         if (op->tsklet.func)
710                 tasklet_kill(&op->tsklet);
711 
712         if (op->thrtsklet.func)
713                 tasklet_kill(&op->thrtsklet);
714 
715         if ((op->frames) && (op->frames != &op->sframe))
716                 kfree(op->frames);
717 
718         if ((op->last_frames) && (op->last_frames != &op->last_sframe))
719                 kfree(op->last_frames);
720 
721         kfree(op);
722 }
723 
724 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
725 {
726         if (op->rx_reg_dev == dev) {
727                 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
728                                   bcm_rx_handler, op);
729 
730                 /* mark as removed subscription */
731                 op->rx_reg_dev = NULL;
732         } else
733                 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
734                        "mismatch %p %p\n", op->rx_reg_dev, dev);
735 }
736 
737 /*
738  * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
739  */
740 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
741 {
742         struct bcm_op *op, *n;
743 
744         list_for_each_entry_safe(op, n, ops, list) {
745                 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
746 
747                         /*
748                          * Don't care if we're bound or not (due to netdev
749                          * problems) can_rx_unregister() is always a save
750                          * thing to do here.
751                          */
752                         if (op->ifindex) {
753                                 /*
754                                  * Only remove subscriptions that had not
755                                  * been removed due to NETDEV_UNREGISTER
756                                  * in bcm_notifier()
757                                  */
758                                 if (op->rx_reg_dev) {
759                                         struct net_device *dev;
760 
761                                         dev = dev_get_by_index(&init_net,
762                                                                op->ifindex);
763                                         if (dev) {
764                                                 bcm_rx_unreg(dev, op);
765                                                 dev_put(dev);
766                                         }
767                                 }
768                         } else
769                                 can_rx_unregister(NULL, op->can_id,
770                                                   REGMASK(op->can_id),
771                                                   bcm_rx_handler, op);
772 
773                         list_del(&op->list);
774                         bcm_remove_op(op);
775                         return 1; /* done */
776                 }
777         }
778 
779         return 0; /* not found */
780 }
781 
782 /*
783  * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
784  */
785 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
786 {
787         struct bcm_op *op, *n;
788 
789         list_for_each_entry_safe(op, n, ops, list) {
790                 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
791                         list_del(&op->list);
792                         bcm_remove_op(op);
793                         return 1; /* done */
794                 }
795         }
796 
797         return 0; /* not found */
798 }
799 
800 /*
801  * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
802  */
803 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
804                        int ifindex)
805 {
806         struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
807 
808         if (!op)
809                 return -EINVAL;
810 
811         /* put current values into msg_head */
812         msg_head->flags   = op->flags;
813         msg_head->count   = op->count;
814         msg_head->ival1   = op->ival1;
815         msg_head->ival2   = op->ival2;
816         msg_head->nframes = op->nframes;
817 
818         bcm_send_to_user(op, msg_head, op->frames, 0);
819 
820         return MHSIZ;
821 }
822 
823 /*
824  * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
825  */
826 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
827                         int ifindex, struct sock *sk)
828 {
829         struct bcm_sock *bo = bcm_sk(sk);
830         struct bcm_op *op;
831         unsigned int i;
832         int err;
833 
834         /* we need a real device to send frames */
835         if (!ifindex)
836                 return -ENODEV;
837 
838         /* check nframes boundaries - we need at least one can_frame */
839         if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
840                 return -EINVAL;
841 
842         /* check the given can_id */
843         op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
844 
845         if (op) {
846                 /* update existing BCM operation */
847 
848                 /*
849                  * Do we need more space for the can_frames than currently
850                  * allocated? -> This is a _really_ unusual use-case and
851                  * therefore (complexity / locking) it is not supported.
852                  */
853                 if (msg_head->nframes > op->nframes)
854                         return -E2BIG;
855 
856                 /* update can_frames content */
857                 for (i = 0; i < msg_head->nframes; i++) {
858                         err = memcpy_fromiovec((u8 *)&op->frames[i],
859                                                msg->msg_iov, CFSIZ);
860 
861                         if (op->frames[i].can_dlc > 8)
862                                 err = -EINVAL;
863 
864                         if (err < 0)
865                                 return err;
866 
867                         if (msg_head->flags & TX_CP_CAN_ID) {
868                                 /* copy can_id into frame */
869                                 op->frames[i].can_id = msg_head->can_id;
870                         }
871                 }
872 
873         } else {
874                 /* insert new BCM operation for the given can_id */
875 
876                 op = kzalloc(OPSIZ, GFP_KERNEL);
877                 if (!op)
878                         return -ENOMEM;
879 
880                 op->can_id    = msg_head->can_id;
881 
882                 /* create array for can_frames and copy the data */
883                 if (msg_head->nframes > 1) {
884                         op->frames = kmalloc(msg_head->nframes * CFSIZ,
885                                              GFP_KERNEL);
886                         if (!op->frames) {
887                                 kfree(op);
888                                 return -ENOMEM;
889                         }
890                 } else
891                         op->frames = &op->sframe;
892 
893                 for (i = 0; i < msg_head->nframes; i++) {
894                         err = memcpy_fromiovec((u8 *)&op->frames[i],
895                                                msg->msg_iov, CFSIZ);
896 
897                         if (op->frames[i].can_dlc > 8)
898                                 err = -EINVAL;
899 
900                         if (err < 0) {
901                                 if (op->frames != &op->sframe)
902                                         kfree(op->frames);
903                                 kfree(op);
904                                 return err;
905                         }
906 
907                         if (msg_head->flags & TX_CP_CAN_ID) {
908                                 /* copy can_id into frame */
909                                 op->frames[i].can_id = msg_head->can_id;
910                         }
911                 }
912 
913                 /* tx_ops never compare with previous received messages */
914                 op->last_frames = NULL;
915 
916                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
917                 op->sk = sk;
918                 op->ifindex = ifindex;
919 
920                 /* initialize uninitialized (kzalloc) structure */
921                 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
922                 op->timer.function = bcm_tx_timeout_handler;
923 
924                 /* initialize tasklet for tx countevent notification */
925                 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
926                              (unsigned long) op);
927 
928                 /* currently unused in tx_ops */
929                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
930 
931                 /* add this bcm_op to the list of the tx_ops */
932                 list_add(&op->list, &bo->tx_ops);
933 
934         } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
935 
936         if (op->nframes != msg_head->nframes) {
937                 op->nframes   = msg_head->nframes;
938                 /* start multiple frame transmission with index 0 */
939                 op->currframe = 0;
940         }
941 
942         /* check flags */
943 
944         op->flags = msg_head->flags;
945 
946         if (op->flags & TX_RESET_MULTI_IDX) {
947                 /* start multiple frame transmission with index 0 */
948                 op->currframe = 0;
949         }
950 
951         if (op->flags & SETTIMER) {
952                 /* set timer values */
953                 op->count = msg_head->count;
954                 op->ival1 = msg_head->ival1;
955                 op->ival2 = msg_head->ival2;
956                 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
957                 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
958 
959                 /* disable an active timer due to zero values? */
960                 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
961                         hrtimer_cancel(&op->timer);
962         }
963 
964         if (op->flags & STARTTIMER) {
965                 hrtimer_cancel(&op->timer);
966                 /* spec: send can_frame when starting timer */
967                 op->flags |= TX_ANNOUNCE;
968         }
969 
970         if (op->flags & TX_ANNOUNCE) {
971                 bcm_can_tx(op);
972                 if (op->count)
973                         op->count--;
974         }
975 
976         if (op->flags & STARTTIMER)
977                 bcm_tx_start_timer(op);
978 
979         return msg_head->nframes * CFSIZ + MHSIZ;
980 }
981 
982 /*
983  * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
984  */
985 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
986                         int ifindex, struct sock *sk)
987 {
988         struct bcm_sock *bo = bcm_sk(sk);
989         struct bcm_op *op;
990         int do_rx_register;
991         int err = 0;
992 
993         if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
994                 /* be robust against wrong usage ... */
995                 msg_head->flags |= RX_FILTER_ID;
996                 /* ignore trailing garbage */
997                 msg_head->nframes = 0;
998         }
999 
1000         /* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1001         if (msg_head->nframes > MAX_NFRAMES + 1)
1002                 return -EINVAL;
1003 
1004         if ((msg_head->flags & RX_RTR_FRAME) &&
1005             ((msg_head->nframes != 1) ||
1006              (!(msg_head->can_id & CAN_RTR_FLAG))))
1007                 return -EINVAL;
1008 
1009         /* check the given can_id */
1010         op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1011         if (op) {
1012                 /* update existing BCM operation */
1013 
1014                 /*
1015                  * Do we need more space for the can_frames than currently
1016                  * allocated? -> This is a _really_ unusual use-case and
1017                  * therefore (complexity / locking) it is not supported.
1018                  */
1019                 if (msg_head->nframes > op->nframes)
1020                         return -E2BIG;
1021 
1022                 if (msg_head->nframes) {
1023                         /* update can_frames content */
1024                         err = memcpy_fromiovec((u8 *)op->frames,
1025                                                msg->msg_iov,
1026                                                msg_head->nframes * CFSIZ);
1027                         if (err < 0)
1028                                 return err;
1029 
1030                         /* clear last_frames to indicate 'nothing received' */
1031                         memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1032                 }
1033 
1034                 op->nframes = msg_head->nframes;
1035 
1036                 /* Only an update -> do not call can_rx_register() */
1037                 do_rx_register = 0;
1038 
1039         } else {
1040                 /* insert new BCM operation for the given can_id */
1041                 op = kzalloc(OPSIZ, GFP_KERNEL);
1042                 if (!op)
1043                         return -ENOMEM;
1044 
1045                 op->can_id    = msg_head->can_id;
1046                 op->nframes   = msg_head->nframes;
1047 
1048                 if (msg_head->nframes > 1) {
1049                         /* create array for can_frames and copy the data */
1050                         op->frames = kmalloc(msg_head->nframes * CFSIZ,
1051                                              GFP_KERNEL);
1052                         if (!op->frames) {
1053                                 kfree(op);
1054                                 return -ENOMEM;
1055                         }
1056 
1057                         /* create and init array for received can_frames */
1058                         op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1059                                                   GFP_KERNEL);
1060                         if (!op->last_frames) {
1061                                 kfree(op->frames);
1062                                 kfree(op);
1063                                 return -ENOMEM;
1064                         }
1065 
1066                 } else {
1067                         op->frames = &op->sframe;
1068                         op->last_frames = &op->last_sframe;
1069                 }
1070 
1071                 if (msg_head->nframes) {
1072                         err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1073                                                msg_head->nframes * CFSIZ);
1074                         if (err < 0) {
1075                                 if (op->frames != &op->sframe)
1076                                         kfree(op->frames);
1077                                 if (op->last_frames != &op->last_sframe)
1078                                         kfree(op->last_frames);
1079                                 kfree(op);
1080                                 return err;
1081                         }
1082                 }
1083 
1084                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1085                 op->sk = sk;
1086                 op->ifindex = ifindex;
1087 
1088                 /* ifindex for timeout events w/o previous frame reception */
1089                 op->rx_ifindex = ifindex;
1090 
1091                 /* initialize uninitialized (kzalloc) structure */
1092                 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1093                 op->timer.function = bcm_rx_timeout_handler;
1094 
1095                 /* initialize tasklet for rx timeout notification */
1096                 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1097                              (unsigned long) op);
1098 
1099                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1100                 op->thrtimer.function = bcm_rx_thr_handler;
1101 
1102                 /* initialize tasklet for rx throttle handling */
1103                 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1104                              (unsigned long) op);
1105 
1106                 /* add this bcm_op to the list of the rx_ops */
1107                 list_add(&op->list, &bo->rx_ops);
1108 
1109                 /* call can_rx_register() */
1110                 do_rx_register = 1;
1111 
1112         } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1113 
1114         /* check flags */
1115         op->flags = msg_head->flags;
1116 
1117         if (op->flags & RX_RTR_FRAME) {
1118 
1119                 /* no timers in RTR-mode */
1120                 hrtimer_cancel(&op->thrtimer);
1121                 hrtimer_cancel(&op->timer);
1122 
1123                 /*
1124                  * funny feature in RX(!)_SETUP only for RTR-mode:
1125                  * copy can_id into frame BUT without RTR-flag to
1126                  * prevent a full-load-loopback-test ... ;-]
1127                  */
1128                 if ((op->flags & TX_CP_CAN_ID) ||
1129                     (op->frames[0].can_id == op->can_id))
1130                         op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1131 
1132         } else {
1133                 if (op->flags & SETTIMER) {
1134 
1135                         /* set timer value */
1136                         op->ival1 = msg_head->ival1;
1137                         op->ival2 = msg_head->ival2;
1138                         op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1139                         op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1140 
1141                         /* disable an active timer due to zero value? */
1142                         if (!op->kt_ival1.tv64)
1143                                 hrtimer_cancel(&op->timer);
1144 
1145                         /*
1146                          * In any case cancel the throttle timer, flush
1147                          * potentially blocked msgs and reset throttle handling
1148                          */
1149                         op->kt_lastmsg = ktime_set(0, 0);
1150                         hrtimer_cancel(&op->thrtimer);
1151                         bcm_rx_thr_flush(op, 1);
1152                 }
1153 
1154                 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1155                         hrtimer_start(&op->timer, op->kt_ival1,
1156                                       HRTIMER_MODE_REL);
1157         }
1158 
1159         /* now we can register for can_ids, if we added a new bcm_op */
1160         if (do_rx_register) {
1161                 if (ifindex) {
1162                         struct net_device *dev;
1163 
1164                         dev = dev_get_by_index(&init_net, ifindex);
1165                         if (dev) {
1166                                 err = can_rx_register(dev, op->can_id,
1167                                                       REGMASK(op->can_id),
1168                                                       bcm_rx_handler, op,
1169                                                       "bcm");
1170 
1171                                 op->rx_reg_dev = dev;
1172                                 dev_put(dev);
1173                         }
1174 
1175                 } else
1176                         err = can_rx_register(NULL, op->can_id,
1177                                               REGMASK(op->can_id),
1178                                               bcm_rx_handler, op, "bcm");
1179                 if (err) {
1180                         /* this bcm rx op is broken -> remove it */
1181                         list_del(&op->list);
1182                         bcm_remove_op(op);
1183                         return err;
1184                 }
1185         }
1186 
1187         return msg_head->nframes * CFSIZ + MHSIZ;
1188 }
1189 
1190 /*
1191  * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1192  */
1193 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1194 {
1195         struct sk_buff *skb;
1196         struct net_device *dev;
1197         int err;
1198 
1199         /* we need a real device to send frames */
1200         if (!ifindex)
1201                 return -ENODEV;
1202 
1203         skb = alloc_skb(CFSIZ, GFP_KERNEL);
1204 
1205         if (!skb)
1206                 return -ENOMEM;
1207 
1208         err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1209         if (err < 0) {
1210                 kfree_skb(skb);
1211                 return err;
1212         }
1213 
1214         dev = dev_get_by_index(&init_net, ifindex);
1215         if (!dev) {
1216                 kfree_skb(skb);
1217                 return -ENODEV;
1218         }
1219 
1220         skb->dev = dev;
1221         skb->sk  = sk;
1222         err = can_send(skb, 1); /* send with loopback */
1223         dev_put(dev);
1224 
1225         if (err)
1226                 return err;
1227 
1228         return CFSIZ + MHSIZ;
1229 }
1230 
1231 /*
1232  * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1233  */
1234 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1235                        struct msghdr *msg, size_t size)
1236 {
1237         struct sock *sk = sock->sk;
1238         struct bcm_sock *bo = bcm_sk(sk);
1239         int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1240         struct bcm_msg_head msg_head;
1241         int ret; /* read bytes or error codes as return value */
1242 
1243         if (!bo->bound)
1244                 return -ENOTCONN;
1245 
1246         /* check for valid message length from userspace */
1247         if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1248                 return -EINVAL;
1249 
1250         /* check for alternative ifindex for this bcm_op */
1251 
1252         if (!ifindex && msg->msg_name) {
1253                 /* no bound device as default => check msg_name */
1254                 struct sockaddr_can *addr =
1255                         (struct sockaddr_can *)msg->msg_name;
1256 
1257                 if (msg->msg_namelen < sizeof(*addr))
1258                         return -EINVAL;
1259 
1260                 if (addr->can_family != AF_CAN)
1261                         return -EINVAL;
1262 
1263                 /* ifindex from sendto() */
1264                 ifindex = addr->can_ifindex;
1265 
1266                 if (ifindex) {
1267                         struct net_device *dev;
1268 
1269                         dev = dev_get_by_index(&init_net, ifindex);
1270                         if (!dev)
1271                                 return -ENODEV;
1272 
1273                         if (dev->type != ARPHRD_CAN) {
1274                                 dev_put(dev);
1275                                 return -ENODEV;
1276                         }
1277 
1278                         dev_put(dev);
1279                 }
1280         }
1281 
1282         /* read message head information */
1283 
1284         ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1285         if (ret < 0)
1286                 return ret;
1287 
1288         lock_sock(sk);
1289 
1290         switch (msg_head.opcode) {
1291 
1292         case TX_SETUP:
1293                 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1294                 break;
1295 
1296         case RX_SETUP:
1297                 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1298                 break;
1299 
1300         case TX_DELETE:
1301                 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1302                         ret = MHSIZ;
1303                 else
1304                         ret = -EINVAL;
1305                 break;
1306 
1307         case RX_DELETE:
1308                 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1309                         ret = MHSIZ;
1310                 else
1311                         ret = -EINVAL;
1312                 break;
1313 
1314         case TX_READ:
1315                 /* reuse msg_head for the reply to TX_READ */
1316                 msg_head.opcode  = TX_STATUS;
1317                 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1318                 break;
1319 
1320         case RX_READ:
1321                 /* reuse msg_head for the reply to RX_READ */
1322                 msg_head.opcode  = RX_STATUS;
1323                 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1324                 break;
1325 
1326         case TX_SEND:
1327                 /* we need exactly one can_frame behind the msg head */
1328                 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1329                         ret = -EINVAL;
1330                 else
1331                         ret = bcm_tx_send(msg, ifindex, sk);
1332                 break;
1333 
1334         default:
1335                 ret = -EINVAL;
1336                 break;
1337         }
1338 
1339         release_sock(sk);
1340 
1341         return ret;
1342 }
1343 
1344 /*
1345  * notification handler for netdevice status changes
1346  */
1347 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1348                         void *data)
1349 {
1350         struct net_device *dev = (struct net_device *)data;
1351         struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1352         struct sock *sk = &bo->sk;
1353         struct bcm_op *op;
1354         int notify_enodev = 0;
1355 
1356         if (!net_eq(dev_net(dev), &init_net))
1357                 return NOTIFY_DONE;
1358 
1359         if (dev->type != ARPHRD_CAN)
1360                 return NOTIFY_DONE;
1361 
1362         switch (msg) {
1363 
1364         case NETDEV_UNREGISTER:
1365                 lock_sock(sk);
1366 
1367                 /* remove device specific receive entries */
1368                 list_for_each_entry(op, &bo->rx_ops, list)
1369                         if (op->rx_reg_dev == dev)
1370                                 bcm_rx_unreg(dev, op);
1371 
1372                 /* remove device reference, if this is our bound device */
1373                 if (bo->bound && bo->ifindex == dev->ifindex) {
1374                         bo->bound   = 0;
1375                         bo->ifindex = 0;
1376                         notify_enodev = 1;
1377                 }
1378 
1379                 release_sock(sk);
1380 
1381                 if (notify_enodev) {
1382                         sk->sk_err = ENODEV;
1383                         if (!sock_flag(sk, SOCK_DEAD))
1384                                 sk->sk_error_report(sk);
1385                 }
1386                 break;
1387 
1388         case NETDEV_DOWN:
1389                 if (bo->bound && bo->ifindex == dev->ifindex) {
1390                         sk->sk_err = ENETDOWN;
1391                         if (!sock_flag(sk, SOCK_DEAD))
1392                                 sk->sk_error_report(sk);
1393                 }
1394         }
1395 
1396         return NOTIFY_DONE;
1397 }
1398 
1399 /*
1400  * initial settings for all BCM sockets to be set at socket creation time
1401  */
1402 static int bcm_init(struct sock *sk)
1403 {
1404         struct bcm_sock *bo = bcm_sk(sk);
1405 
1406         bo->bound            = 0;
1407         bo->ifindex          = 0;
1408         bo->dropped_usr_msgs = 0;
1409         bo->bcm_proc_read    = NULL;
1410 
1411         INIT_LIST_HEAD(&bo->tx_ops);
1412         INIT_LIST_HEAD(&bo->rx_ops);
1413 
1414         /* set notifier */
1415         bo->notifier.notifier_call = bcm_notifier;
1416 
1417         register_netdevice_notifier(&bo->notifier);
1418 
1419         return 0;
1420 }
1421 
1422 /*
1423  * standard socket functions
1424  */
1425 static int bcm_release(struct socket *sock)
1426 {
1427         struct sock *sk = sock->sk;
1428         struct bcm_sock *bo;
1429         struct bcm_op *op, *next;
1430 
1431         if (sk == NULL)
1432                 return 0;
1433 
1434         bo = bcm_sk(sk);
1435 
1436         /* remove bcm_ops, timer, rx_unregister(), etc. */
1437 
1438         unregister_netdevice_notifier(&bo->notifier);
1439 
1440         lock_sock(sk);
1441 
1442         list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1443                 bcm_remove_op(op);
1444 
1445         list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1446                 /*
1447                  * Don't care if we're bound or not (due to netdev problems)
1448                  * can_rx_unregister() is always a save thing to do here.
1449                  */
1450                 if (op->ifindex) {
1451                         /*
1452                          * Only remove subscriptions that had not
1453                          * been removed due to NETDEV_UNREGISTER
1454                          * in bcm_notifier()
1455                          */
1456                         if (op->rx_reg_dev) {
1457                                 struct net_device *dev;
1458 
1459                                 dev = dev_get_by_index(&init_net, op->ifindex);
1460                                 if (dev) {
1461                                         bcm_rx_unreg(dev, op);
1462                                         dev_put(dev);
1463                                 }
1464                         }
1465                 } else
1466                         can_rx_unregister(NULL, op->can_id,
1467                                           REGMASK(op->can_id),
1468                                           bcm_rx_handler, op);
1469 
1470                 bcm_remove_op(op);
1471         }
1472 
1473         /* remove procfs entry */
1474         if (proc_dir && bo->bcm_proc_read)
1475                 remove_proc_entry(bo->procname, proc_dir);
1476 
1477         /* remove device reference */
1478         if (bo->bound) {
1479                 bo->bound   = 0;
1480                 bo->ifindex = 0;
1481         }
1482 
1483         sock_orphan(sk);
1484         sock->sk = NULL;
1485 
1486         release_sock(sk);
1487         sock_put(sk);
1488 
1489         return 0;
1490 }
1491 
1492 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1493                        int flags)
1494 {
1495         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1496         struct sock *sk = sock->sk;
1497         struct bcm_sock *bo = bcm_sk(sk);
1498 
1499         if (len < sizeof(*addr))
1500                 return -EINVAL;
1501 
1502         if (bo->bound)
1503                 return -EISCONN;
1504 
1505         /* bind a device to this socket */
1506         if (addr->can_ifindex) {
1507                 struct net_device *dev;
1508 
1509                 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1510                 if (!dev)
1511                         return -ENODEV;
1512 
1513                 if (dev->type != ARPHRD_CAN) {
1514                         dev_put(dev);
1515                         return -ENODEV;
1516                 }
1517 
1518                 bo->ifindex = dev->ifindex;
1519                 dev_put(dev);
1520 
1521         } else {
1522                 /* no interface reference for ifindex = 0 ('any' CAN device) */
1523                 bo->ifindex = 0;
1524         }
1525 
1526         bo->bound = 1;
1527 
1528         if (proc_dir) {
1529                 /* unique socket address as filename */
1530                 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1531                 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1532                                                      proc_dir,
1533                                                      &bcm_proc_fops, sk);
1534         }
1535 
1536         return 0;
1537 }
1538 
1539 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1540                        struct msghdr *msg, size_t size, int flags)
1541 {
1542         struct sock *sk = sock->sk;
1543         struct sk_buff *skb;
1544         int error = 0;
1545         int noblock;
1546         int err;
1547 
1548         noblock =  flags & MSG_DONTWAIT;
1549         flags   &= ~MSG_DONTWAIT;
1550         skb = skb_recv_datagram(sk, flags, noblock, &error);
1551         if (!skb)
1552                 return error;
1553 
1554         if (skb->len < size)
1555                 size = skb->len;
1556 
1557         err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1558         if (err < 0) {
1559                 skb_free_datagram(sk, skb);
1560                 return err;
1561         }
1562 
1563         sock_recv_ts_and_drops(msg, sk, skb);
1564 
1565         if (msg->msg_name) {
1566                 msg->msg_namelen = sizeof(struct sockaddr_can);
1567                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1568         }
1569 
1570         skb_free_datagram(sk, skb);
1571 
1572         return size;
1573 }
1574 
1575 static const struct proto_ops bcm_ops = {
1576         .family        = PF_CAN,
1577         .release       = bcm_release,
1578         .bind          = sock_no_bind,
1579         .connect       = bcm_connect,
1580         .socketpair    = sock_no_socketpair,
1581         .accept        = sock_no_accept,
1582         .getname       = sock_no_getname,
1583         .poll          = datagram_poll,
1584         .ioctl         = can_ioctl,     /* use can_ioctl() from af_can.c */
1585         .listen        = sock_no_listen,
1586         .shutdown      = sock_no_shutdown,
1587         .setsockopt    = sock_no_setsockopt,
1588         .getsockopt    = sock_no_getsockopt,
1589         .sendmsg       = bcm_sendmsg,
1590         .recvmsg       = bcm_recvmsg,
1591         .mmap          = sock_no_mmap,
1592         .sendpage      = sock_no_sendpage,
1593 };
1594 
1595 static struct proto bcm_proto __read_mostly = {
1596         .name       = "CAN_BCM",
1597         .owner      = THIS_MODULE,
1598         .obj_size   = sizeof(struct bcm_sock),
1599         .init       = bcm_init,
1600 };
1601 
1602 static const struct can_proto bcm_can_proto = {
1603         .type       = SOCK_DGRAM,
1604         .protocol   = CAN_BCM,
1605         .ops        = &bcm_ops,
1606         .prot       = &bcm_proto,
1607 };
1608 
1609 static int __init bcm_module_init(void)
1610 {
1611         int err;
1612 
1613         printk(banner);
1614 
1615         err = can_proto_register(&bcm_can_proto);
1616         if (err < 0) {
1617                 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1618                 return err;
1619         }
1620 
1621         /* create /proc/net/can-bcm directory */
1622         proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1623         return 0;
1624 }
1625 
1626 static void __exit bcm_module_exit(void)
1627 {
1628         can_proto_unregister(&bcm_can_proto);
1629 
1630         if (proc_dir)
1631                 proc_net_remove(&init_net, "can-bcm");
1632 }
1633 
1634 module_init(bcm_module_init);
1635 module_exit(bcm_module_exit);
1636 

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