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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  */
 41 
 42 #include <linux/module.h>
 43 #include <linux/init.h>
 44 #include <linux/interrupt.h>
 45 #include <linux/hrtimer.h>
 46 #include <linux/list.h>
 47 #include <linux/proc_fs.h>
 48 #include <linux/seq_file.h>
 49 #include <linux/uio.h>
 50 #include <linux/net.h>
 51 #include <linux/netdevice.h>
 52 #include <linux/socket.h>
 53 #include <linux/if_arp.h>
 54 #include <linux/skbuff.h>
 55 #include <linux/can.h>
 56 #include <linux/can/core.h>
 57 #include <linux/can/skb.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 __initconst 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 + sizeof(struct can_skb_priv), gfp_any());
261         if (!skb)
262                 goto out;
263 
264         can_skb_reserve(skb);
265         can_skb_prv(skb)->ifindex = dev->ifindex;
266 
267         memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
268 
269         /* send with loopback */
270         skb->dev = dev;
271         skb->sk = op->sk;
272         can_send(skb, 1);
273 
274         /* update statistics */
275         op->currframe++;
276         op->frames_abs++;
277 
278         /* reached last frame? */
279         if (op->currframe >= op->nframes)
280                 op->currframe = 0;
281  out:
282         dev_put(dev);
283 }
284 
285 /*
286  * bcm_send_to_user - send a BCM message to the userspace
287  *                    (consisting of bcm_msg_head + x CAN frames)
288  */
289 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
290                              struct can_frame *frames, int has_timestamp)
291 {
292         struct sk_buff *skb;
293         struct can_frame *firstframe;
294         struct sockaddr_can *addr;
295         struct sock *sk = op->sk;
296         unsigned int datalen = head->nframes * CFSIZ;
297         int err;
298 
299         skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
300         if (!skb)
301                 return;
302 
303         memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
304 
305         if (head->nframes) {
306                 /* can_frames starting here */
307                 firstframe = (struct can_frame *)skb_tail_pointer(skb);
308 
309                 memcpy(skb_put(skb, datalen), frames, datalen);
310 
311                 /*
312                  * the BCM uses the can_dlc-element of the can_frame
313                  * structure for internal purposes. This is only
314                  * relevant for updates that are generated by the
315                  * BCM, where nframes is 1
316                  */
317                 if (head->nframes == 1)
318                         firstframe->can_dlc &= BCM_CAN_DLC_MASK;
319         }
320 
321         if (has_timestamp) {
322                 /* restore rx timestamp */
323                 skb->tstamp = op->rx_stamp;
324         }
325 
326         /*
327          *  Put the datagram to the queue so that bcm_recvmsg() can
328          *  get it from there.  We need to pass the interface index to
329          *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
330          *  containing the interface index.
331          */
332 
333         BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
334         addr = (struct sockaddr_can *)skb->cb;
335         memset(addr, 0, sizeof(*addr));
336         addr->can_family  = AF_CAN;
337         addr->can_ifindex = op->rx_ifindex;
338 
339         err = sock_queue_rcv_skb(sk, skb);
340         if (err < 0) {
341                 struct bcm_sock *bo = bcm_sk(sk);
342 
343                 kfree_skb(skb);
344                 /* don't care about overflows in this statistic */
345                 bo->dropped_usr_msgs++;
346         }
347 }
348 
349 static void bcm_tx_start_timer(struct bcm_op *op)
350 {
351         if (op->kt_ival1.tv64 && op->count)
352                 hrtimer_start(&op->timer,
353                               ktime_add(ktime_get(), op->kt_ival1),
354                               HRTIMER_MODE_ABS);
355         else if (op->kt_ival2.tv64)
356                 hrtimer_start(&op->timer,
357                               ktime_add(ktime_get(), op->kt_ival2),
358                               HRTIMER_MODE_ABS);
359 }
360 
361 static void bcm_tx_timeout_tsklet(unsigned long data)
362 {
363         struct bcm_op *op = (struct bcm_op *)data;
364         struct bcm_msg_head msg_head;
365 
366         if (op->kt_ival1.tv64 && (op->count > 0)) {
367 
368                 op->count--;
369                 if (!op->count && (op->flags & TX_COUNTEVT)) {
370 
371                         /* create notification to user */
372                         msg_head.opcode  = TX_EXPIRED;
373                         msg_head.flags   = op->flags;
374                         msg_head.count   = op->count;
375                         msg_head.ival1   = op->ival1;
376                         msg_head.ival2   = op->ival2;
377                         msg_head.can_id  = op->can_id;
378                         msg_head.nframes = 0;
379 
380                         bcm_send_to_user(op, &msg_head, NULL, 0);
381                 }
382                 bcm_can_tx(op);
383 
384         } else if (op->kt_ival2.tv64)
385                 bcm_can_tx(op);
386 
387         bcm_tx_start_timer(op);
388 }
389 
390 /*
391  * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
392  */
393 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
394 {
395         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
396 
397         tasklet_schedule(&op->tsklet);
398 
399         return HRTIMER_NORESTART;
400 }
401 
402 /*
403  * bcm_rx_changed - create a RX_CHANGED notification due to changed content
404  */
405 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
406 {
407         struct bcm_msg_head head;
408 
409         /* update statistics */
410         op->frames_filtered++;
411 
412         /* prevent statistics overflow */
413         if (op->frames_filtered > ULONG_MAX/100)
414                 op->frames_filtered = op->frames_abs = 0;
415 
416         /* this element is not throttled anymore */
417         data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
418 
419         head.opcode  = RX_CHANGED;
420         head.flags   = op->flags;
421         head.count   = op->count;
422         head.ival1   = op->ival1;
423         head.ival2   = op->ival2;
424         head.can_id  = op->can_id;
425         head.nframes = 1;
426 
427         bcm_send_to_user(op, &head, data, 1);
428 }
429 
430 /*
431  * bcm_rx_update_and_send - process a detected relevant receive content change
432  *                          1. update the last received data
433  *                          2. send a notification to the user (if possible)
434  */
435 static void bcm_rx_update_and_send(struct bcm_op *op,
436                                    struct can_frame *lastdata,
437                                    const struct can_frame *rxdata)
438 {
439         memcpy(lastdata, rxdata, CFSIZ);
440 
441         /* mark as used and throttled by default */
442         lastdata->can_dlc |= (RX_RECV|RX_THR);
443 
444         /* throtteling mode inactive ? */
445         if (!op->kt_ival2.tv64) {
446                 /* send RX_CHANGED to the user immediately */
447                 bcm_rx_changed(op, lastdata);
448                 return;
449         }
450 
451         /* with active throttling timer we are just done here */
452         if (hrtimer_active(&op->thrtimer))
453                 return;
454 
455         /* first receiption with enabled throttling mode */
456         if (!op->kt_lastmsg.tv64)
457                 goto rx_changed_settime;
458 
459         /* got a second frame inside a potential throttle period? */
460         if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
461             ktime_to_us(op->kt_ival2)) {
462                 /* do not send the saved data - only start throttle timer */
463                 hrtimer_start(&op->thrtimer,
464                               ktime_add(op->kt_lastmsg, op->kt_ival2),
465                               HRTIMER_MODE_ABS);
466                 return;
467         }
468 
469         /* the gap was that big, that throttling was not needed here */
470 rx_changed_settime:
471         bcm_rx_changed(op, lastdata);
472         op->kt_lastmsg = ktime_get();
473 }
474 
475 /*
476  * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
477  *                       received data stored in op->last_frames[]
478  */
479 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
480                                 const struct can_frame *rxdata)
481 {
482         /*
483          * no one uses the MSBs of can_dlc for comparation,
484          * so we use it here to detect the first time of reception
485          */
486 
487         if (!(op->last_frames[index].can_dlc & RX_RECV)) {
488                 /* received data for the first time => send update to user */
489                 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
490                 return;
491         }
492 
493         /* do a real check in can_frame data section */
494 
495         if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
496             (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
497                 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
498                 return;
499         }
500 
501         if (op->flags & RX_CHECK_DLC) {
502                 /* do a real check in can_frame dlc */
503                 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
504                                         BCM_CAN_DLC_MASK)) {
505                         bcm_rx_update_and_send(op, &op->last_frames[index],
506                                                rxdata);
507                         return;
508                 }
509         }
510 }
511 
512 /*
513  * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
514  */
515 static void bcm_rx_starttimer(struct bcm_op *op)
516 {
517         if (op->flags & RX_NO_AUTOTIMER)
518                 return;
519 
520         if (op->kt_ival1.tv64)
521                 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
522 }
523 
524 static void bcm_rx_timeout_tsklet(unsigned long data)
525 {
526         struct bcm_op *op = (struct bcm_op *)data;
527         struct bcm_msg_head msg_head;
528 
529         /* create notification to user */
530         msg_head.opcode  = RX_TIMEOUT;
531         msg_head.flags   = op->flags;
532         msg_head.count   = op->count;
533         msg_head.ival1   = op->ival1;
534         msg_head.ival2   = op->ival2;
535         msg_head.can_id  = op->can_id;
536         msg_head.nframes = 0;
537 
538         bcm_send_to_user(op, &msg_head, NULL, 0);
539 }
540 
541 /*
542  * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
543  */
544 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
545 {
546         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
547 
548         /* schedule before NET_RX_SOFTIRQ */
549         tasklet_hi_schedule(&op->tsklet);
550 
551         /* no restart of the timer is done here! */
552 
553         /* if user wants to be informed, when cyclic CAN-Messages come back */
554         if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
555                 /* clear received can_frames to indicate 'nothing received' */
556                 memset(op->last_frames, 0, op->nframes * CFSIZ);
557         }
558 
559         return HRTIMER_NORESTART;
560 }
561 
562 /*
563  * bcm_rx_do_flush - helper for bcm_rx_thr_flush
564  */
565 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
566                                   unsigned int index)
567 {
568         if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
569                 if (update)
570                         bcm_rx_changed(op, &op->last_frames[index]);
571                 return 1;
572         }
573         return 0;
574 }
575 
576 /*
577  * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
578  *
579  * update == 0 : just check if throttled data is available  (any irq context)
580  * update == 1 : check and send throttled data to userspace (soft_irq context)
581  */
582 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
583 {
584         int updated = 0;
585 
586         if (op->nframes > 1) {
587                 unsigned int i;
588 
589                 /* for MUX filter we start at index 1 */
590                 for (i = 1; i < op->nframes; i++)
591                         updated += bcm_rx_do_flush(op, update, i);
592 
593         } else {
594                 /* for RX_FILTER_ID and simple filter */
595                 updated += bcm_rx_do_flush(op, update, 0);
596         }
597 
598         return updated;
599 }
600 
601 static void bcm_rx_thr_tsklet(unsigned long data)
602 {
603         struct bcm_op *op = (struct bcm_op *)data;
604 
605         /* push the changed data to the userspace */
606         bcm_rx_thr_flush(op, 1);
607 }
608 
609 /*
610  * bcm_rx_thr_handler - the time for blocked content updates is over now:
611  *                      Check for throttled data and send it to the userspace
612  */
613 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
614 {
615         struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
616 
617         tasklet_schedule(&op->thrtsklet);
618 
619         if (bcm_rx_thr_flush(op, 0)) {
620                 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
621                 return HRTIMER_RESTART;
622         } else {
623                 /* rearm throttle handling */
624                 op->kt_lastmsg = ktime_set(0, 0);
625                 return HRTIMER_NORESTART;
626         }
627 }
628 
629 /*
630  * bcm_rx_handler - handle a CAN frame receiption
631  */
632 static void bcm_rx_handler(struct sk_buff *skb, void *data)
633 {
634         struct bcm_op *op = (struct bcm_op *)data;
635         const struct can_frame *rxframe = (struct can_frame *)skb->data;
636         unsigned int i;
637 
638         /* disable timeout */
639         hrtimer_cancel(&op->timer);
640 
641         if (op->can_id != rxframe->can_id)
642                 return;
643 
644         /* save rx timestamp */
645         op->rx_stamp = skb->tstamp;
646         /* save originator for recvfrom() */
647         op->rx_ifindex = skb->dev->ifindex;
648         /* update statistics */
649         op->frames_abs++;
650 
651         if (op->flags & RX_RTR_FRAME) {
652                 /* send reply for RTR-request (placed in op->frames[0]) */
653                 bcm_can_tx(op);
654                 return;
655         }
656 
657         if (op->flags & RX_FILTER_ID) {
658                 /* the easiest case */
659                 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
660                 goto rx_starttimer;
661         }
662 
663         if (op->nframes == 1) {
664                 /* simple compare with index 0 */
665                 bcm_rx_cmp_to_index(op, 0, rxframe);
666                 goto rx_starttimer;
667         }
668 
669         if (op->nframes > 1) {
670                 /*
671                  * multiplex compare
672                  *
673                  * find the first multiplex mask that fits.
674                  * Remark: The MUX-mask is stored in index 0
675                  */
676 
677                 for (i = 1; i < op->nframes; i++) {
678                         if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
679                             (GET_U64(&op->frames[0]) &
680                              GET_U64(&op->frames[i]))) {
681                                 bcm_rx_cmp_to_index(op, i, rxframe);
682                                 break;
683                         }
684                 }
685         }
686 
687 rx_starttimer:
688         bcm_rx_starttimer(op);
689 }
690 
691 /*
692  * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
693  */
694 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
695                                   int ifindex)
696 {
697         struct bcm_op *op;
698 
699         list_for_each_entry(op, ops, list) {
700                 if ((op->can_id == can_id) && (op->ifindex == ifindex))
701                         return op;
702         }
703 
704         return NULL;
705 }
706 
707 static void bcm_remove_op(struct bcm_op *op)
708 {
709         hrtimer_cancel(&op->timer);
710         hrtimer_cancel(&op->thrtimer);
711 
712         if (op->tsklet.func)
713                 tasklet_kill(&op->tsklet);
714 
715         if (op->thrtsklet.func)
716                 tasklet_kill(&op->thrtsklet);
717 
718         if ((op->frames) && (op->frames != &op->sframe))
719                 kfree(op->frames);
720 
721         if ((op->last_frames) && (op->last_frames != &op->last_sframe))
722                 kfree(op->last_frames);
723 
724         kfree(op);
725 }
726 
727 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
728 {
729         if (op->rx_reg_dev == dev) {
730                 can_rx_unregister(dev, op->can_id, REGMASK(op->can_id),
731                                   bcm_rx_handler, op);
732 
733                 /* mark as removed subscription */
734                 op->rx_reg_dev = NULL;
735         } else
736                 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
737                        "mismatch %p %p\n", op->rx_reg_dev, dev);
738 }
739 
740 /*
741  * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
742  */
743 static int bcm_delete_rx_op(struct list_head *ops, canid_t can_id, int ifindex)
744 {
745         struct bcm_op *op, *n;
746 
747         list_for_each_entry_safe(op, n, ops, list) {
748                 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
749 
750                         /*
751                          * Don't care if we're bound or not (due to netdev
752                          * problems) can_rx_unregister() is always a save
753                          * thing to do here.
754                          */
755                         if (op->ifindex) {
756                                 /*
757                                  * Only remove subscriptions that had not
758                                  * been removed due to NETDEV_UNREGISTER
759                                  * in bcm_notifier()
760                                  */
761                                 if (op->rx_reg_dev) {
762                                         struct net_device *dev;
763 
764                                         dev = dev_get_by_index(&init_net,
765                                                                op->ifindex);
766                                         if (dev) {
767                                                 bcm_rx_unreg(dev, op);
768                                                 dev_put(dev);
769                                         }
770                                 }
771                         } else
772                                 can_rx_unregister(NULL, op->can_id,
773                                                   REGMASK(op->can_id),
774                                                   bcm_rx_handler, op);
775 
776                         list_del(&op->list);
777                         bcm_remove_op(op);
778                         return 1; /* done */
779                 }
780         }
781 
782         return 0; /* not found */
783 }
784 
785 /*
786  * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
787  */
788 static int bcm_delete_tx_op(struct list_head *ops, canid_t can_id, int ifindex)
789 {
790         struct bcm_op *op, *n;
791 
792         list_for_each_entry_safe(op, n, ops, list) {
793                 if ((op->can_id == can_id) && (op->ifindex == ifindex)) {
794                         list_del(&op->list);
795                         bcm_remove_op(op);
796                         return 1; /* done */
797                 }
798         }
799 
800         return 0; /* not found */
801 }
802 
803 /*
804  * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
805  */
806 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
807                        int ifindex)
808 {
809         struct bcm_op *op = bcm_find_op(ops, msg_head->can_id, ifindex);
810 
811         if (!op)
812                 return -EINVAL;
813 
814         /* put current values into msg_head */
815         msg_head->flags   = op->flags;
816         msg_head->count   = op->count;
817         msg_head->ival1   = op->ival1;
818         msg_head->ival2   = op->ival2;
819         msg_head->nframes = op->nframes;
820 
821         bcm_send_to_user(op, msg_head, op->frames, 0);
822 
823         return MHSIZ;
824 }
825 
826 /*
827  * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
828  */
829 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
830                         int ifindex, struct sock *sk)
831 {
832         struct bcm_sock *bo = bcm_sk(sk);
833         struct bcm_op *op;
834         unsigned int i;
835         int err;
836 
837         /* we need a real device to send frames */
838         if (!ifindex)
839                 return -ENODEV;
840 
841         /* check nframes boundaries - we need at least one can_frame */
842         if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
843                 return -EINVAL;
844 
845         /* check the given can_id */
846         op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex);
847 
848         if (op) {
849                 /* update existing BCM operation */
850 
851                 /*
852                  * Do we need more space for the can_frames than currently
853                  * allocated? -> This is a _really_ unusual use-case and
854                  * therefore (complexity / locking) it is not supported.
855                  */
856                 if (msg_head->nframes > op->nframes)
857                         return -E2BIG;
858 
859                 /* update can_frames content */
860                 for (i = 0; i < msg_head->nframes; i++) {
861                         err = memcpy_fromiovec((u8 *)&op->frames[i],
862                                                msg->msg_iov, CFSIZ);
863 
864                         if (op->frames[i].can_dlc > 8)
865                                 err = -EINVAL;
866 
867                         if (err < 0)
868                                 return err;
869 
870                         if (msg_head->flags & TX_CP_CAN_ID) {
871                                 /* copy can_id into frame */
872                                 op->frames[i].can_id = msg_head->can_id;
873                         }
874                 }
875 
876         } else {
877                 /* insert new BCM operation for the given can_id */
878 
879                 op = kzalloc(OPSIZ, GFP_KERNEL);
880                 if (!op)
881                         return -ENOMEM;
882 
883                 op->can_id    = msg_head->can_id;
884 
885                 /* create array for can_frames and copy the data */
886                 if (msg_head->nframes > 1) {
887                         op->frames = kmalloc(msg_head->nframes * CFSIZ,
888                                              GFP_KERNEL);
889                         if (!op->frames) {
890                                 kfree(op);
891                                 return -ENOMEM;
892                         }
893                 } else
894                         op->frames = &op->sframe;
895 
896                 for (i = 0; i < msg_head->nframes; i++) {
897                         err = memcpy_fromiovec((u8 *)&op->frames[i],
898                                                msg->msg_iov, CFSIZ);
899 
900                         if (op->frames[i].can_dlc > 8)
901                                 err = -EINVAL;
902 
903                         if (err < 0) {
904                                 if (op->frames != &op->sframe)
905                                         kfree(op->frames);
906                                 kfree(op);
907                                 return err;
908                         }
909 
910                         if (msg_head->flags & TX_CP_CAN_ID) {
911                                 /* copy can_id into frame */
912                                 op->frames[i].can_id = msg_head->can_id;
913                         }
914                 }
915 
916                 /* tx_ops never compare with previous received messages */
917                 op->last_frames = NULL;
918 
919                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
920                 op->sk = sk;
921                 op->ifindex = ifindex;
922 
923                 /* initialize uninitialized (kzalloc) structure */
924                 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
925                 op->timer.function = bcm_tx_timeout_handler;
926 
927                 /* initialize tasklet for tx countevent notification */
928                 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
929                              (unsigned long) op);
930 
931                 /* currently unused in tx_ops */
932                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
933 
934                 /* add this bcm_op to the list of the tx_ops */
935                 list_add(&op->list, &bo->tx_ops);
936 
937         } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
938 
939         if (op->nframes != msg_head->nframes) {
940                 op->nframes   = msg_head->nframes;
941                 /* start multiple frame transmission with index 0 */
942                 op->currframe = 0;
943         }
944 
945         /* check flags */
946 
947         op->flags = msg_head->flags;
948 
949         if (op->flags & TX_RESET_MULTI_IDX) {
950                 /* start multiple frame transmission with index 0 */
951                 op->currframe = 0;
952         }
953 
954         if (op->flags & SETTIMER) {
955                 /* set timer values */
956                 op->count = msg_head->count;
957                 op->ival1 = msg_head->ival1;
958                 op->ival2 = msg_head->ival2;
959                 op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
960                 op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
961 
962                 /* disable an active timer due to zero values? */
963                 if (!op->kt_ival1.tv64 && !op->kt_ival2.tv64)
964                         hrtimer_cancel(&op->timer);
965         }
966 
967         if (op->flags & STARTTIMER) {
968                 hrtimer_cancel(&op->timer);
969                 /* spec: send can_frame when starting timer */
970                 op->flags |= TX_ANNOUNCE;
971         }
972 
973         if (op->flags & TX_ANNOUNCE) {
974                 bcm_can_tx(op);
975                 if (op->count)
976                         op->count--;
977         }
978 
979         if (op->flags & STARTTIMER)
980                 bcm_tx_start_timer(op);
981 
982         return msg_head->nframes * CFSIZ + MHSIZ;
983 }
984 
985 /*
986  * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
987  */
988 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
989                         int ifindex, struct sock *sk)
990 {
991         struct bcm_sock *bo = bcm_sk(sk);
992         struct bcm_op *op;
993         int do_rx_register;
994         int err = 0;
995 
996         if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
997                 /* be robust against wrong usage ... */
998                 msg_head->flags |= RX_FILTER_ID;
999                 /* ignore trailing garbage */
1000                 msg_head->nframes = 0;
1001         }
1002 
1003         /* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1004         if (msg_head->nframes > MAX_NFRAMES + 1)
1005                 return -EINVAL;
1006 
1007         if ((msg_head->flags & RX_RTR_FRAME) &&
1008             ((msg_head->nframes != 1) ||
1009              (!(msg_head->can_id & CAN_RTR_FLAG))))
1010                 return -EINVAL;
1011 
1012         /* check the given can_id */
1013         op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1014         if (op) {
1015                 /* update existing BCM operation */
1016 
1017                 /*
1018                  * Do we need more space for the can_frames than currently
1019                  * allocated? -> This is a _really_ unusual use-case and
1020                  * therefore (complexity / locking) it is not supported.
1021                  */
1022                 if (msg_head->nframes > op->nframes)
1023                         return -E2BIG;
1024 
1025                 if (msg_head->nframes) {
1026                         /* update can_frames content */
1027                         err = memcpy_fromiovec((u8 *)op->frames,
1028                                                msg->msg_iov,
1029                                                msg_head->nframes * CFSIZ);
1030                         if (err < 0)
1031                                 return err;
1032 
1033                         /* clear last_frames to indicate 'nothing received' */
1034                         memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1035                 }
1036 
1037                 op->nframes = msg_head->nframes;
1038 
1039                 /* Only an update -> do not call can_rx_register() */
1040                 do_rx_register = 0;
1041 
1042         } else {
1043                 /* insert new BCM operation for the given can_id */
1044                 op = kzalloc(OPSIZ, GFP_KERNEL);
1045                 if (!op)
1046                         return -ENOMEM;
1047 
1048                 op->can_id    = msg_head->can_id;
1049                 op->nframes   = msg_head->nframes;
1050 
1051                 if (msg_head->nframes > 1) {
1052                         /* create array for can_frames and copy the data */
1053                         op->frames = kmalloc(msg_head->nframes * CFSIZ,
1054                                              GFP_KERNEL);
1055                         if (!op->frames) {
1056                                 kfree(op);
1057                                 return -ENOMEM;
1058                         }
1059 
1060                         /* create and init array for received can_frames */
1061                         op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1062                                                   GFP_KERNEL);
1063                         if (!op->last_frames) {
1064                                 kfree(op->frames);
1065                                 kfree(op);
1066                                 return -ENOMEM;
1067                         }
1068 
1069                 } else {
1070                         op->frames = &op->sframe;
1071                         op->last_frames = &op->last_sframe;
1072                 }
1073 
1074                 if (msg_head->nframes) {
1075                         err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1076                                                msg_head->nframes * CFSIZ);
1077                         if (err < 0) {
1078                                 if (op->frames != &op->sframe)
1079                                         kfree(op->frames);
1080                                 if (op->last_frames != &op->last_sframe)
1081                                         kfree(op->last_frames);
1082                                 kfree(op);
1083                                 return err;
1084                         }
1085                 }
1086 
1087                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1088                 op->sk = sk;
1089                 op->ifindex = ifindex;
1090 
1091                 /* ifindex for timeout events w/o previous frame reception */
1092                 op->rx_ifindex = ifindex;
1093 
1094                 /* initialize uninitialized (kzalloc) structure */
1095                 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1096                 op->timer.function = bcm_rx_timeout_handler;
1097 
1098                 /* initialize tasklet for rx timeout notification */
1099                 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1100                              (unsigned long) op);
1101 
1102                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1103                 op->thrtimer.function = bcm_rx_thr_handler;
1104 
1105                 /* initialize tasklet for rx throttle handling */
1106                 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1107                              (unsigned long) op);
1108 
1109                 /* add this bcm_op to the list of the rx_ops */
1110                 list_add(&op->list, &bo->rx_ops);
1111 
1112                 /* call can_rx_register() */
1113                 do_rx_register = 1;
1114 
1115         } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1116 
1117         /* check flags */
1118         op->flags = msg_head->flags;
1119 
1120         if (op->flags & RX_RTR_FRAME) {
1121 
1122                 /* no timers in RTR-mode */
1123                 hrtimer_cancel(&op->thrtimer);
1124                 hrtimer_cancel(&op->timer);
1125 
1126                 /*
1127                  * funny feature in RX(!)_SETUP only for RTR-mode:
1128                  * copy can_id into frame BUT without RTR-flag to
1129                  * prevent a full-load-loopback-test ... ;-]
1130                  */
1131                 if ((op->flags & TX_CP_CAN_ID) ||
1132                     (op->frames[0].can_id == op->can_id))
1133                         op->frames[0].can_id = op->can_id & ~CAN_RTR_FLAG;
1134 
1135         } else {
1136                 if (op->flags & SETTIMER) {
1137 
1138                         /* set timer value */
1139                         op->ival1 = msg_head->ival1;
1140                         op->ival2 = msg_head->ival2;
1141                         op->kt_ival1 = timeval_to_ktime(msg_head->ival1);
1142                         op->kt_ival2 = timeval_to_ktime(msg_head->ival2);
1143 
1144                         /* disable an active timer due to zero value? */
1145                         if (!op->kt_ival1.tv64)
1146                                 hrtimer_cancel(&op->timer);
1147 
1148                         /*
1149                          * In any case cancel the throttle timer, flush
1150                          * potentially blocked msgs and reset throttle handling
1151                          */
1152                         op->kt_lastmsg = ktime_set(0, 0);
1153                         hrtimer_cancel(&op->thrtimer);
1154                         bcm_rx_thr_flush(op, 1);
1155                 }
1156 
1157                 if ((op->flags & STARTTIMER) && op->kt_ival1.tv64)
1158                         hrtimer_start(&op->timer, op->kt_ival1,
1159                                       HRTIMER_MODE_REL);
1160         }
1161 
1162         /* now we can register for can_ids, if we added a new bcm_op */
1163         if (do_rx_register) {
1164                 if (ifindex) {
1165                         struct net_device *dev;
1166 
1167                         dev = dev_get_by_index(&init_net, ifindex);
1168                         if (dev) {
1169                                 err = can_rx_register(dev, op->can_id,
1170                                                       REGMASK(op->can_id),
1171                                                       bcm_rx_handler, op,
1172                                                       "bcm");
1173 
1174                                 op->rx_reg_dev = dev;
1175                                 dev_put(dev);
1176                         }
1177 
1178                 } else
1179                         err = can_rx_register(NULL, op->can_id,
1180                                               REGMASK(op->can_id),
1181                                               bcm_rx_handler, op, "bcm");
1182                 if (err) {
1183                         /* this bcm rx op is broken -> remove it */
1184                         list_del(&op->list);
1185                         bcm_remove_op(op);
1186                         return err;
1187                 }
1188         }
1189 
1190         return msg_head->nframes * CFSIZ + MHSIZ;
1191 }
1192 
1193 /*
1194  * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1195  */
1196 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1197 {
1198         struct sk_buff *skb;
1199         struct net_device *dev;
1200         int err;
1201 
1202         /* we need a real device to send frames */
1203         if (!ifindex)
1204                 return -ENODEV;
1205 
1206         skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), GFP_KERNEL);
1207         if (!skb)
1208                 return -ENOMEM;
1209 
1210         can_skb_reserve(skb);
1211 
1212         err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1213         if (err < 0) {
1214                 kfree_skb(skb);
1215                 return err;
1216         }
1217 
1218         dev = dev_get_by_index(&init_net, ifindex);
1219         if (!dev) {
1220                 kfree_skb(skb);
1221                 return -ENODEV;
1222         }
1223 
1224         can_skb_prv(skb)->ifindex = dev->ifindex;
1225         skb->dev = dev;
1226         skb->sk  = sk;
1227         err = can_send(skb, 1); /* send with loopback */
1228         dev_put(dev);
1229 
1230         if (err)
1231                 return err;
1232 
1233         return CFSIZ + MHSIZ;
1234 }
1235 
1236 /*
1237  * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1238  */
1239 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1240                        struct msghdr *msg, size_t size)
1241 {
1242         struct sock *sk = sock->sk;
1243         struct bcm_sock *bo = bcm_sk(sk);
1244         int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1245         struct bcm_msg_head msg_head;
1246         int ret; /* read bytes or error codes as return value */
1247 
1248         if (!bo->bound)
1249                 return -ENOTCONN;
1250 
1251         /* check for valid message length from userspace */
1252         if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1253                 return -EINVAL;
1254 
1255         /* check for alternative ifindex for this bcm_op */
1256 
1257         if (!ifindex && msg->msg_name) {
1258                 /* no bound device as default => check msg_name */
1259                 struct sockaddr_can *addr =
1260                         (struct sockaddr_can *)msg->msg_name;
1261 
1262                 if (msg->msg_namelen < sizeof(*addr))
1263                         return -EINVAL;
1264 
1265                 if (addr->can_family != AF_CAN)
1266                         return -EINVAL;
1267 
1268                 /* ifindex from sendto() */
1269                 ifindex = addr->can_ifindex;
1270 
1271                 if (ifindex) {
1272                         struct net_device *dev;
1273 
1274                         dev = dev_get_by_index(&init_net, ifindex);
1275                         if (!dev)
1276                                 return -ENODEV;
1277 
1278                         if (dev->type != ARPHRD_CAN) {
1279                                 dev_put(dev);
1280                                 return -ENODEV;
1281                         }
1282 
1283                         dev_put(dev);
1284                 }
1285         }
1286 
1287         /* read message head information */
1288 
1289         ret = memcpy_fromiovec((u8 *)&msg_head, msg->msg_iov, MHSIZ);
1290         if (ret < 0)
1291                 return ret;
1292 
1293         lock_sock(sk);
1294 
1295         switch (msg_head.opcode) {
1296 
1297         case TX_SETUP:
1298                 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1299                 break;
1300 
1301         case RX_SETUP:
1302                 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1303                 break;
1304 
1305         case TX_DELETE:
1306                 if (bcm_delete_tx_op(&bo->tx_ops, msg_head.can_id, ifindex))
1307                         ret = MHSIZ;
1308                 else
1309                         ret = -EINVAL;
1310                 break;
1311 
1312         case RX_DELETE:
1313                 if (bcm_delete_rx_op(&bo->rx_ops, msg_head.can_id, ifindex))
1314                         ret = MHSIZ;
1315                 else
1316                         ret = -EINVAL;
1317                 break;
1318 
1319         case TX_READ:
1320                 /* reuse msg_head for the reply to TX_READ */
1321                 msg_head.opcode  = TX_STATUS;
1322                 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1323                 break;
1324 
1325         case RX_READ:
1326                 /* reuse msg_head for the reply to RX_READ */
1327                 msg_head.opcode  = RX_STATUS;
1328                 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1329                 break;
1330 
1331         case TX_SEND:
1332                 /* we need exactly one can_frame behind the msg head */
1333                 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1334                         ret = -EINVAL;
1335                 else
1336                         ret = bcm_tx_send(msg, ifindex, sk);
1337                 break;
1338 
1339         default:
1340                 ret = -EINVAL;
1341                 break;
1342         }
1343 
1344         release_sock(sk);
1345 
1346         return ret;
1347 }
1348 
1349 /*
1350  * notification handler for netdevice status changes
1351  */
1352 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1353                         void *data)
1354 {
1355         struct net_device *dev = (struct net_device *)data;
1356         struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1357         struct sock *sk = &bo->sk;
1358         struct bcm_op *op;
1359         int notify_enodev = 0;
1360 
1361         if (!net_eq(dev_net(dev), &init_net))
1362                 return NOTIFY_DONE;
1363 
1364         if (dev->type != ARPHRD_CAN)
1365                 return NOTIFY_DONE;
1366 
1367         switch (msg) {
1368 
1369         case NETDEV_UNREGISTER:
1370                 lock_sock(sk);
1371 
1372                 /* remove device specific receive entries */
1373                 list_for_each_entry(op, &bo->rx_ops, list)
1374                         if (op->rx_reg_dev == dev)
1375                                 bcm_rx_unreg(dev, op);
1376 
1377                 /* remove device reference, if this is our bound device */
1378                 if (bo->bound && bo->ifindex == dev->ifindex) {
1379                         bo->bound   = 0;
1380                         bo->ifindex = 0;
1381                         notify_enodev = 1;
1382                 }
1383 
1384                 release_sock(sk);
1385 
1386                 if (notify_enodev) {
1387                         sk->sk_err = ENODEV;
1388                         if (!sock_flag(sk, SOCK_DEAD))
1389                                 sk->sk_error_report(sk);
1390                 }
1391                 break;
1392 
1393         case NETDEV_DOWN:
1394                 if (bo->bound && bo->ifindex == dev->ifindex) {
1395                         sk->sk_err = ENETDOWN;
1396                         if (!sock_flag(sk, SOCK_DEAD))
1397                                 sk->sk_error_report(sk);
1398                 }
1399         }
1400 
1401         return NOTIFY_DONE;
1402 }
1403 
1404 /*
1405  * initial settings for all BCM sockets to be set at socket creation time
1406  */
1407 static int bcm_init(struct sock *sk)
1408 {
1409         struct bcm_sock *bo = bcm_sk(sk);
1410 
1411         bo->bound            = 0;
1412         bo->ifindex          = 0;
1413         bo->dropped_usr_msgs = 0;
1414         bo->bcm_proc_read    = NULL;
1415 
1416         INIT_LIST_HEAD(&bo->tx_ops);
1417         INIT_LIST_HEAD(&bo->rx_ops);
1418 
1419         /* set notifier */
1420         bo->notifier.notifier_call = bcm_notifier;
1421 
1422         register_netdevice_notifier(&bo->notifier);
1423 
1424         return 0;
1425 }
1426 
1427 /*
1428  * standard socket functions
1429  */
1430 static int bcm_release(struct socket *sock)
1431 {
1432         struct sock *sk = sock->sk;
1433         struct bcm_sock *bo;
1434         struct bcm_op *op, *next;
1435 
1436         if (sk == NULL)
1437                 return 0;
1438 
1439         bo = bcm_sk(sk);
1440 
1441         /* remove bcm_ops, timer, rx_unregister(), etc. */
1442 
1443         unregister_netdevice_notifier(&bo->notifier);
1444 
1445         lock_sock(sk);
1446 
1447         list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1448                 bcm_remove_op(op);
1449 
1450         list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1451                 /*
1452                  * Don't care if we're bound or not (due to netdev problems)
1453                  * can_rx_unregister() is always a save thing to do here.
1454                  */
1455                 if (op->ifindex) {
1456                         /*
1457                          * Only remove subscriptions that had not
1458                          * been removed due to NETDEV_UNREGISTER
1459                          * in bcm_notifier()
1460                          */
1461                         if (op->rx_reg_dev) {
1462                                 struct net_device *dev;
1463 
1464                                 dev = dev_get_by_index(&init_net, op->ifindex);
1465                                 if (dev) {
1466                                         bcm_rx_unreg(dev, op);
1467                                         dev_put(dev);
1468                                 }
1469                         }
1470                 } else
1471                         can_rx_unregister(NULL, op->can_id,
1472                                           REGMASK(op->can_id),
1473                                           bcm_rx_handler, op);
1474 
1475                 bcm_remove_op(op);
1476         }
1477 
1478         /* remove procfs entry */
1479         if (proc_dir && bo->bcm_proc_read)
1480                 remove_proc_entry(bo->procname, proc_dir);
1481 
1482         /* remove device reference */
1483         if (bo->bound) {
1484                 bo->bound   = 0;
1485                 bo->ifindex = 0;
1486         }
1487 
1488         sock_orphan(sk);
1489         sock->sk = NULL;
1490 
1491         release_sock(sk);
1492         sock_put(sk);
1493 
1494         return 0;
1495 }
1496 
1497 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1498                        int flags)
1499 {
1500         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1501         struct sock *sk = sock->sk;
1502         struct bcm_sock *bo = bcm_sk(sk);
1503 
1504         if (len < sizeof(*addr))
1505                 return -EINVAL;
1506 
1507         if (bo->bound)
1508                 return -EISCONN;
1509 
1510         /* bind a device to this socket */
1511         if (addr->can_ifindex) {
1512                 struct net_device *dev;
1513 
1514                 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1515                 if (!dev)
1516                         return -ENODEV;
1517 
1518                 if (dev->type != ARPHRD_CAN) {
1519                         dev_put(dev);
1520                         return -ENODEV;
1521                 }
1522 
1523                 bo->ifindex = dev->ifindex;
1524                 dev_put(dev);
1525 
1526         } else {
1527                 /* no interface reference for ifindex = 0 ('any' CAN device) */
1528                 bo->ifindex = 0;
1529         }
1530 
1531         bo->bound = 1;
1532 
1533         if (proc_dir) {
1534                 /* unique socket address as filename */
1535                 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1536                 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1537                                                      proc_dir,
1538                                                      &bcm_proc_fops, sk);
1539         }
1540 
1541         return 0;
1542 }
1543 
1544 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1545                        struct msghdr *msg, size_t size, int flags)
1546 {
1547         struct sock *sk = sock->sk;
1548         struct sk_buff *skb;
1549         int error = 0;
1550         int noblock;
1551         int err;
1552 
1553         noblock =  flags & MSG_DONTWAIT;
1554         flags   &= ~MSG_DONTWAIT;
1555         skb = skb_recv_datagram(sk, flags, noblock, &error);
1556         if (!skb)
1557                 return error;
1558 
1559         if (skb->len < size)
1560                 size = skb->len;
1561 
1562         err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1563         if (err < 0) {
1564                 skb_free_datagram(sk, skb);
1565                 return err;
1566         }
1567 
1568         sock_recv_ts_and_drops(msg, sk, skb);
1569 
1570         if (msg->msg_name) {
1571                 msg->msg_namelen = sizeof(struct sockaddr_can);
1572                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1573         }
1574 
1575         skb_free_datagram(sk, skb);
1576 
1577         return size;
1578 }
1579 
1580 static const struct proto_ops bcm_ops = {
1581         .family        = PF_CAN,
1582         .release       = bcm_release,
1583         .bind          = sock_no_bind,
1584         .connect       = bcm_connect,
1585         .socketpair    = sock_no_socketpair,
1586         .accept        = sock_no_accept,
1587         .getname       = sock_no_getname,
1588         .poll          = datagram_poll,
1589         .ioctl         = can_ioctl,     /* use can_ioctl() from af_can.c */
1590         .listen        = sock_no_listen,
1591         .shutdown      = sock_no_shutdown,
1592         .setsockopt    = sock_no_setsockopt,
1593         .getsockopt    = sock_no_getsockopt,
1594         .sendmsg       = bcm_sendmsg,
1595         .recvmsg       = bcm_recvmsg,
1596         .mmap          = sock_no_mmap,
1597         .sendpage      = sock_no_sendpage,
1598 };
1599 
1600 static struct proto bcm_proto __read_mostly = {
1601         .name       = "CAN_BCM",
1602         .owner      = THIS_MODULE,
1603         .obj_size   = sizeof(struct bcm_sock),
1604         .init       = bcm_init,
1605 };
1606 
1607 static const struct can_proto bcm_can_proto = {
1608         .type       = SOCK_DGRAM,
1609         .protocol   = CAN_BCM,
1610         .ops        = &bcm_ops,
1611         .prot       = &bcm_proto,
1612 };
1613 
1614 static int __init bcm_module_init(void)
1615 {
1616         int err;
1617 
1618         printk(banner);
1619 
1620         err = can_proto_register(&bcm_can_proto);
1621         if (err < 0) {
1622                 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1623                 return err;
1624         }
1625 
1626         /* create /proc/net/can-bcm directory */
1627         proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1628         return 0;
1629 }
1630 
1631 static void __exit bcm_module_exit(void)
1632 {
1633         can_proto_unregister(&bcm_can_proto);
1634 
1635         if (proc_dir)
1636                 remove_proc_entry("can-bcm", init_net.proc_net);
1637 }
1638 
1639 module_init(bcm_module_init);
1640 module_exit(bcm_module_exit);
1641 

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