~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/can/bcm.c

Version: ~ [ linux-5.18 ] ~ [ linux-5.17.9 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.41 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.117 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.195 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.244 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.280 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.315 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 <net/sock.h>
 60 #include <net/net_namespace.h>
 61 
 62 /*
 63  * To send multiple CAN frame content within TX_SETUP or to filter
 64  * CAN messages with multiplex index within RX_SETUP, the number of
 65  * different filters is limited to 256 due to the one byte index value.
 66  */
 67 #define MAX_NFRAMES 256
 68 
 69 /* use of last_frames[index].can_dlc */
 70 #define RX_RECV    0x40 /* received data for this element */
 71 #define RX_THR     0x80 /* element not been sent due to throttle feature */
 72 #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */
 73 
 74 /* get best masking value for can_rx_register() for a given single can_id */
 75 #define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
 76                      (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
 77                      (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
 78 
 79 #define CAN_BCM_VERSION CAN_VERSION
 80 static __initdata const char banner[] = KERN_INFO
 81         "can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n";
 82 
 83 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
 84 MODULE_LICENSE("Dual BSD/GPL");
 85 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
 86 MODULE_ALIAS("can-proto-2");
 87 
 88 /* easy access to can_frame payload */
 89 static inline u64 GET_U64(const struct can_frame *cp)
 90 {
 91         return *(u64 *)cp->data;
 92 }
 93 
 94 struct bcm_op {
 95         struct list_head list;
 96         int ifindex;
 97         canid_t can_id;
 98         u32 flags;
 99         unsigned long frames_abs, frames_filtered;
100         struct timeval ival1, ival2;
101         struct hrtimer timer, thrtimer;
102         struct tasklet_struct tsklet, thrtsklet;
103         ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
104         int rx_ifindex;
105         u32 count;
106         u32 nframes;
107         u32 currframe;
108         struct can_frame *frames;
109         struct can_frame *last_frames;
110         struct can_frame sframe;
111         struct can_frame last_sframe;
112         struct sock *sk;
113         struct net_device *rx_reg_dev;
114 };
115 
116 static struct proc_dir_entry *proc_dir;
117 
118 struct bcm_sock {
119         struct sock sk;
120         int bound;
121         int ifindex;
122         struct notifier_block notifier;
123         struct list_head rx_ops;
124         struct list_head tx_ops;
125         unsigned long dropped_usr_msgs;
126         struct proc_dir_entry *bcm_proc_read;
127         char procname [32]; /* inode number in decimal with \0 */
128 };
129 
130 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
131 {
132         return (struct bcm_sock *)sk;
133 }
134 
135 #define CFSIZ sizeof(struct can_frame)
136 #define OPSIZ sizeof(struct bcm_op)
137 #define MHSIZ sizeof(struct bcm_msg_head)
138 
139 /*
140  * procfs functions
141  */
142 static char *bcm_proc_getifname(char *result, int ifindex)
143 {
144         struct net_device *dev;
145 
146         if (!ifindex)
147                 return "any";
148 
149         read_lock(&dev_base_lock);
150         dev = __dev_get_by_index(&init_net, ifindex);
151         if (dev)
152                 strcpy(result, dev->name);
153         else
154                 strcpy(result, "???");
155         read_unlock(&dev_base_lock);
156 
157         return result;
158 }
159 
160 static int bcm_proc_show(struct seq_file *m, void *v)
161 {
162         char ifname[IFNAMSIZ];
163         struct sock *sk = (struct sock *)m->private;
164         struct bcm_sock *bo = bcm_sk(sk);
165         struct bcm_op *op;
166 
167         seq_printf(m, ">>> socket %p", sk->sk_socket);
168         seq_printf(m, " / sk %p", sk);
169         seq_printf(m, " / bo %p", bo);
170         seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
171         seq_printf(m, " / bound %s", bcm_proc_getifname(ifname, bo->ifindex));
172         seq_printf(m, " <<<\n");
173 
174         list_for_each_entry(op, &bo->rx_ops, list) {
175 
176                 unsigned long reduction;
177 
178                 /* print only active entries & prevent division by zero */
179                 if (!op->frames_abs)
180                         continue;
181 
182                 seq_printf(m, "rx_op: %03X %-5s ",
183                                 op->can_id, bcm_proc_getifname(ifname, op->ifindex));
184                 seq_printf(m, "[%u]%c ", op->nframes,
185                                 (op->flags & RX_CHECK_DLC)?'d':' ');
186                 if (op->kt_ival1.tv64)
187                         seq_printf(m, "timeo=%lld ",
188                                         (long long)
189                                         ktime_to_us(op->kt_ival1));
190 
191                 if (op->kt_ival2.tv64)
192                         seq_printf(m, "thr=%lld ",
193                                         (long long)
194                                         ktime_to_us(op->kt_ival2));
195 
196                 seq_printf(m, "# recv %ld (%ld) => reduction: ",
197                                 op->frames_filtered, op->frames_abs);
198 
199                 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
200 
201                 seq_printf(m, "%s%ld%%\n",
202                                 (reduction == 100)?"near ":"", reduction);
203         }
204 
205         list_for_each_entry(op, &bo->tx_ops, list) {
206 
207                 seq_printf(m, "tx_op: %03X %s [%u] ",
208                                 op->can_id,
209                                 bcm_proc_getifname(ifname, op->ifindex),
210                                 op->nframes);
211 
212                 if (op->kt_ival1.tv64)
213                         seq_printf(m, "t1=%lld ",
214                                         (long long) ktime_to_us(op->kt_ival1));
215 
216                 if (op->kt_ival2.tv64)
217                         seq_printf(m, "t2=%lld ",
218                                         (long long) ktime_to_us(op->kt_ival2));
219 
220                 seq_printf(m, "# sent %ld\n", op->frames_abs);
221         }
222         seq_putc(m, '\n');
223         return 0;
224 }
225 
226 static int bcm_proc_open(struct inode *inode, struct file *file)
227 {
228         return single_open(file, bcm_proc_show, PDE(inode)->data);
229 }
230 
231 static const struct file_operations bcm_proc_fops = {
232         .owner          = THIS_MODULE,
233         .open           = bcm_proc_open,
234         .read           = seq_read,
235         .llseek         = seq_lseek,
236         .release        = single_release,
237 };
238 
239 /*
240  * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
241  *              of the given bcm tx op
242  */
243 static void bcm_can_tx(struct bcm_op *op)
244 {
245         struct sk_buff *skb;
246         struct net_device *dev;
247         struct can_frame *cf = &op->frames[op->currframe];
248 
249         /* no target device? => exit */
250         if (!op->ifindex)
251                 return;
252 
253         dev = dev_get_by_index(&init_net, op->ifindex);
254         if (!dev) {
255                 /* RFC: should this bcm_op remove itself here? */
256                 return;
257         }
258 
259         skb = alloc_skb(CFSIZ, gfp_any());
260         if (!skb)
261                 goto out;
262 
263         memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
264 
265         /* send with loopback */
266         skb->dev = dev;
267         skb->sk = op->sk;
268         can_send(skb, 1);
269 
270         /* update statistics */
271         op->currframe++;
272         op->frames_abs++;
273 
274         /* reached last frame? */
275         if (op->currframe >= op->nframes)
276                 op->currframe = 0;
277  out:
278         dev_put(dev);
279 }
280 
281 /*
282  * bcm_send_to_user - send a BCM message to the userspace
283  *                    (consisting of bcm_msg_head + x CAN frames)
284  */
285 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
286                              struct can_frame *frames, int has_timestamp)
287 {
288         struct sk_buff *skb;
289         struct can_frame *firstframe;
290         struct sockaddr_can *addr;
291         struct sock *sk = op->sk;
292         unsigned int datalen = head->nframes * CFSIZ;
293         int err;
294 
295         skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
296         if (!skb)
297                 return;
298 
299         memcpy(skb_put(skb, sizeof(*head)), head, sizeof(*head));
300 
301         if (head->nframes) {
302                 /* can_frames starting here */
303                 firstframe = (struct can_frame *)skb_tail_pointer(skb);
304 
305                 memcpy(skb_put(skb, datalen), frames, datalen);
306 
307                 /*
308                  * the BCM uses the can_dlc-element of the can_frame
309                  * structure for internal purposes. This is only
310                  * relevant for updates that are generated by the
311                  * BCM, where nframes is 1
312                  */
313                 if (head->nframes == 1)
314                         firstframe->can_dlc &= BCM_CAN_DLC_MASK;
315         }
316 
317         if (has_timestamp) {
318                 /* restore rx timestamp */
319                 skb->tstamp = op->rx_stamp;
320         }
321 
322         /*
323          *  Put the datagram to the queue so that bcm_recvmsg() can
324          *  get it from there.  We need to pass the interface index to
325          *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
326          *  containing the interface index.
327          */
328 
329         BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
330         addr = (struct sockaddr_can *)skb->cb;
331         memset(addr, 0, sizeof(*addr));
332         addr->can_family  = AF_CAN;
333         addr->can_ifindex = op->rx_ifindex;
334 
335         err = sock_queue_rcv_skb(sk, skb);
336         if (err < 0) {
337                 struct bcm_sock *bo = bcm_sk(sk);
338 
339                 kfree_skb(skb);
340                 /* don't care about overflows in this statistic */
341                 bo->dropped_usr_msgs++;
342         }
343 }
344 
345 static void bcm_tx_timeout_tsklet(unsigned long data)
346 {
347         struct bcm_op *op = (struct bcm_op *)data;
348         struct bcm_msg_head msg_head;
349 
350         if (op->kt_ival1.tv64 && (op->count > 0)) {
351 
352                 op->count--;
353                 if (!op->count && (op->flags & TX_COUNTEVT)) {
354 
355                         /* create notification to user */
356                         msg_head.opcode  = TX_EXPIRED;
357                         msg_head.flags   = op->flags;
358                         msg_head.count   = op->count;
359                         msg_head.ival1   = op->ival1;
360                         msg_head.ival2   = op->ival2;
361                         msg_head.can_id  = op->can_id;
362                         msg_head.nframes = 0;
363 
364                         bcm_send_to_user(op, &msg_head, NULL, 0);
365                 }
366         }
367 
368         if (op->kt_ival1.tv64 && (op->count > 0)) {
369 
370                 /* send (next) frame */
371                 bcm_can_tx(op);
372                 hrtimer_start(&op->timer,
373                               ktime_add(ktime_get(), op->kt_ival1),
374                               HRTIMER_MODE_ABS);
375 
376         } else {
377                 if (op->kt_ival2.tv64) {
378 
379                         /* send (next) frame */
380                         bcm_can_tx(op);
381                         hrtimer_start(&op->timer,
382                                       ktime_add(ktime_get(), op->kt_ival2),
383                                       HRTIMER_MODE_ABS);
384                 }
385         }
386 }
387 
388 /*
389  * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions
390  */
391 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
392 {
393         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
394 
395         tasklet_schedule(&op->tsklet);
396 
397         return HRTIMER_NORESTART;
398 }
399 
400 /*
401  * bcm_rx_changed - create a RX_CHANGED notification due to changed content
402  */
403 static void bcm_rx_changed(struct bcm_op *op, struct can_frame *data)
404 {
405         struct bcm_msg_head head;
406 
407         /* update statistics */
408         op->frames_filtered++;
409 
410         /* prevent statistics overflow */
411         if (op->frames_filtered > ULONG_MAX/100)
412                 op->frames_filtered = op->frames_abs = 0;
413 
414         /* this element is not throttled anymore */
415         data->can_dlc &= (BCM_CAN_DLC_MASK|RX_RECV);
416 
417         head.opcode  = RX_CHANGED;
418         head.flags   = op->flags;
419         head.count   = op->count;
420         head.ival1   = op->ival1;
421         head.ival2   = op->ival2;
422         head.can_id  = op->can_id;
423         head.nframes = 1;
424 
425         bcm_send_to_user(op, &head, data, 1);
426 }
427 
428 /*
429  * bcm_rx_update_and_send - process a detected relevant receive content change
430  *                          1. update the last received data
431  *                          2. send a notification to the user (if possible)
432  */
433 static void bcm_rx_update_and_send(struct bcm_op *op,
434                                    struct can_frame *lastdata,
435                                    const struct can_frame *rxdata)
436 {
437         memcpy(lastdata, rxdata, CFSIZ);
438 
439         /* mark as used and throttled by default */
440         lastdata->can_dlc |= (RX_RECV|RX_THR);
441 
442         /* throtteling mode inactive ? */
443         if (!op->kt_ival2.tv64) {
444                 /* send RX_CHANGED to the user immediately */
445                 bcm_rx_changed(op, lastdata);
446                 return;
447         }
448 
449         /* with active throttling timer we are just done here */
450         if (hrtimer_active(&op->thrtimer))
451                 return;
452 
453         /* first receiption with enabled throttling mode */
454         if (!op->kt_lastmsg.tv64)
455                 goto rx_changed_settime;
456 
457         /* got a second frame inside a potential throttle period? */
458         if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
459             ktime_to_us(op->kt_ival2)) {
460                 /* do not send the saved data - only start throttle timer */
461                 hrtimer_start(&op->thrtimer,
462                               ktime_add(op->kt_lastmsg, op->kt_ival2),
463                               HRTIMER_MODE_ABS);
464                 return;
465         }
466 
467         /* the gap was that big, that throttling was not needed here */
468 rx_changed_settime:
469         bcm_rx_changed(op, lastdata);
470         op->kt_lastmsg = ktime_get();
471 }
472 
473 /*
474  * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
475  *                       received data stored in op->last_frames[]
476  */
477 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
478                                 const struct can_frame *rxdata)
479 {
480         /*
481          * no one uses the MSBs of can_dlc for comparation,
482          * so we use it here to detect the first time of reception
483          */
484 
485         if (!(op->last_frames[index].can_dlc & RX_RECV)) {
486                 /* received data for the first time => send update to user */
487                 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
488                 return;
489         }
490 
491         /* do a real check in can_frame data section */
492 
493         if ((GET_U64(&op->frames[index]) & GET_U64(rxdata)) !=
494             (GET_U64(&op->frames[index]) & GET_U64(&op->last_frames[index]))) {
495                 bcm_rx_update_and_send(op, &op->last_frames[index], rxdata);
496                 return;
497         }
498 
499         if (op->flags & RX_CHECK_DLC) {
500                 /* do a real check in can_frame dlc */
501                 if (rxdata->can_dlc != (op->last_frames[index].can_dlc &
502                                         BCM_CAN_DLC_MASK)) {
503                         bcm_rx_update_and_send(op, &op->last_frames[index],
504                                                rxdata);
505                         return;
506                 }
507         }
508 }
509 
510 /*
511  * bcm_rx_starttimer - enable timeout monitoring for CAN frame receiption
512  */
513 static void bcm_rx_starttimer(struct bcm_op *op)
514 {
515         if (op->flags & RX_NO_AUTOTIMER)
516                 return;
517 
518         if (op->kt_ival1.tv64)
519                 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
520 }
521 
522 static void bcm_rx_timeout_tsklet(unsigned long data)
523 {
524         struct bcm_op *op = (struct bcm_op *)data;
525         struct bcm_msg_head msg_head;
526 
527         /* create notification to user */
528         msg_head.opcode  = RX_TIMEOUT;
529         msg_head.flags   = op->flags;
530         msg_head.count   = op->count;
531         msg_head.ival1   = op->ival1;
532         msg_head.ival2   = op->ival2;
533         msg_head.can_id  = op->can_id;
534         msg_head.nframes = 0;
535 
536         bcm_send_to_user(op, &msg_head, NULL, 0);
537 }
538 
539 /*
540  * bcm_rx_timeout_handler - when the (cyclic) CAN frame receiption timed out
541  */
542 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
543 {
544         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
545 
546         /* schedule before NET_RX_SOFTIRQ */
547         tasklet_hi_schedule(&op->tsklet);
548 
549         /* no restart of the timer is done here! */
550 
551         /* if user wants to be informed, when cyclic CAN-Messages come back */
552         if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
553                 /* clear received can_frames to indicate 'nothing received' */
554                 memset(op->last_frames, 0, op->nframes * CFSIZ);
555         }
556 
557         return HRTIMER_NORESTART;
558 }
559 
560 /*
561  * bcm_rx_do_flush - helper for bcm_rx_thr_flush
562  */
563 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
564                                   unsigned int index)
565 {
566         if ((op->last_frames) && (op->last_frames[index].can_dlc & RX_THR)) {
567                 if (update)
568                         bcm_rx_changed(op, &op->last_frames[index]);
569                 return 1;
570         }
571         return 0;
572 }
573 
574 /*
575  * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
576  *
577  * update == 0 : just check if throttled data is available  (any irq context)
578  * update == 1 : check and send throttled data to userspace (soft_irq context)
579  */
580 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
581 {
582         int updated = 0;
583 
584         if (op->nframes > 1) {
585                 unsigned int i;
586 
587                 /* for MUX filter we start at index 1 */
588                 for (i = 1; i < op->nframes; i++)
589                         updated += bcm_rx_do_flush(op, update, i);
590 
591         } else {
592                 /* for RX_FILTER_ID and simple filter */
593                 updated += bcm_rx_do_flush(op, update, 0);
594         }
595 
596         return updated;
597 }
598 
599 static void bcm_rx_thr_tsklet(unsigned long data)
600 {
601         struct bcm_op *op = (struct bcm_op *)data;
602 
603         /* push the changed data to the userspace */
604         bcm_rx_thr_flush(op, 1);
605 }
606 
607 /*
608  * bcm_rx_thr_handler - the time for blocked content updates is over now:
609  *                      Check for throttled data and send it to the userspace
610  */
611 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
612 {
613         struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
614 
615         tasklet_schedule(&op->thrtsklet);
616 
617         if (bcm_rx_thr_flush(op, 0)) {
618                 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
619                 return HRTIMER_RESTART;
620         } else {
621                 /* rearm throttle handling */
622                 op->kt_lastmsg = ktime_set(0, 0);
623                 return HRTIMER_NORESTART;
624         }
625 }
626 
627 /*
628  * bcm_rx_handler - handle a CAN frame receiption
629  */
630 static void bcm_rx_handler(struct sk_buff *skb, void *data)
631 {
632         struct bcm_op *op = (struct bcm_op *)data;
633         const struct can_frame *rxframe = (struct can_frame *)skb->data;
634         unsigned int i;
635 
636         /* disable timeout */
637         hrtimer_cancel(&op->timer);
638 
639         if (op->can_id != rxframe->can_id)
640                 return;
641 
642         /* save rx timestamp */
643         op->rx_stamp = skb->tstamp;
644         /* save originator for recvfrom() */
645         op->rx_ifindex = skb->dev->ifindex;
646         /* update statistics */
647         op->frames_abs++;
648 
649         if (op->flags & RX_RTR_FRAME) {
650                 /* send reply for RTR-request (placed in op->frames[0]) */
651                 bcm_can_tx(op);
652                 return;
653         }
654 
655         if (op->flags & RX_FILTER_ID) {
656                 /* the easiest case */
657                 bcm_rx_update_and_send(op, &op->last_frames[0], rxframe);
658                 goto rx_starttimer;
659         }
660 
661         if (op->nframes == 1) {
662                 /* simple compare with index 0 */
663                 bcm_rx_cmp_to_index(op, 0, rxframe);
664                 goto rx_starttimer;
665         }
666 
667         if (op->nframes > 1) {
668                 /*
669                  * multiplex compare
670                  *
671                  * find the first multiplex mask that fits.
672                  * Remark: The MUX-mask is stored in index 0
673                  */
674 
675                 for (i = 1; i < op->nframes; i++) {
676                         if ((GET_U64(&op->frames[0]) & GET_U64(rxframe)) ==
677                             (GET_U64(&op->frames[0]) &
678                              GET_U64(&op->frames[i]))) {
679                                 bcm_rx_cmp_to_index(op, i, rxframe);
680                                 break;
681                         }
682                 }
683         }
684 
685 rx_starttimer:
686         bcm_rx_starttimer(op);
687 }
688 
689 /*
690  * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
691  */
692 static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
693                                   int ifindex)
694 {
695         struct bcm_op *op;
696 
697         list_for_each_entry(op, ops, list) {
698                 if ((op->can_id == can_id) && (op->ifindex == ifindex))
699                         return op;
700         }
701 
702         return NULL;
703 }
704 
705 static void bcm_remove_op(struct bcm_op *op)
706 {
707         hrtimer_cancel(&op->timer);
708         hrtimer_cancel(&op->thrtimer);
709 
710         if (op->tsklet.func)
711                 tasklet_kill(&op->tsklet);
712 
713         if (op->thrtsklet.func)
714                 tasklet_kill(&op->thrtsklet);
715 
716         if ((op->frames) && (op->frames != &op->sframe))
717                 kfree(op->frames);
718 
719         if ((op->last_frames) && (op->last_frames != &op->last_sframe))
720                 kfree(op->last_frames);
721 
722         kfree(op);
723 
724         return;
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             ((op->kt_ival1.tv64 && op->count) || op->kt_ival2.tv64)) {
969 
970                 /* spec: send can_frame when starting timer */
971                 op->flags |= TX_ANNOUNCE;
972 
973                 if (op->kt_ival1.tv64 && (op->count > 0)) {
974                         /* op->count-- is done in bcm_tx_timeout_handler */
975                         hrtimer_start(&op->timer, op->kt_ival1,
976                                       HRTIMER_MODE_REL);
977                 } else
978                         hrtimer_start(&op->timer, op->kt_ival2,
979                                       HRTIMER_MODE_REL);
980         }
981 
982         if (op->flags & TX_ANNOUNCE)
983                 bcm_can_tx(op);
984 
985         return msg_head->nframes * CFSIZ + MHSIZ;
986 }
987 
988 /*
989  * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
990  */
991 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
992                         int ifindex, struct sock *sk)
993 {
994         struct bcm_sock *bo = bcm_sk(sk);
995         struct bcm_op *op;
996         int do_rx_register;
997         int err = 0;
998 
999         if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1000                 /* be robust against wrong usage ... */
1001                 msg_head->flags |= RX_FILTER_ID;
1002                 /* ignore trailing garbage */
1003                 msg_head->nframes = 0;
1004         }
1005 
1006         /* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1007         if (msg_head->nframes > MAX_NFRAMES + 1)
1008                 return -EINVAL;
1009 
1010         if ((msg_head->flags & RX_RTR_FRAME) &&
1011             ((msg_head->nframes != 1) ||
1012              (!(msg_head->can_id & CAN_RTR_FLAG))))
1013                 return -EINVAL;
1014 
1015         /* check the given can_id */
1016         op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex);
1017         if (op) {
1018                 /* update existing BCM operation */
1019 
1020                 /*
1021                  * Do we need more space for the can_frames than currently
1022                  * allocated? -> This is a _really_ unusual use-case and
1023                  * therefore (complexity / locking) it is not supported.
1024                  */
1025                 if (msg_head->nframes > op->nframes)
1026                         return -E2BIG;
1027 
1028                 if (msg_head->nframes) {
1029                         /* update can_frames content */
1030                         err = memcpy_fromiovec((u8 *)op->frames,
1031                                                msg->msg_iov,
1032                                                msg_head->nframes * CFSIZ);
1033                         if (err < 0)
1034                                 return err;
1035 
1036                         /* clear last_frames to indicate 'nothing received' */
1037                         memset(op->last_frames, 0, msg_head->nframes * CFSIZ);
1038                 }
1039 
1040                 op->nframes = msg_head->nframes;
1041 
1042                 /* Only an update -> do not call can_rx_register() */
1043                 do_rx_register = 0;
1044 
1045         } else {
1046                 /* insert new BCM operation for the given can_id */
1047                 op = kzalloc(OPSIZ, GFP_KERNEL);
1048                 if (!op)
1049                         return -ENOMEM;
1050 
1051                 op->can_id    = msg_head->can_id;
1052                 op->nframes   = msg_head->nframes;
1053 
1054                 if (msg_head->nframes > 1) {
1055                         /* create array for can_frames and copy the data */
1056                         op->frames = kmalloc(msg_head->nframes * CFSIZ,
1057                                              GFP_KERNEL);
1058                         if (!op->frames) {
1059                                 kfree(op);
1060                                 return -ENOMEM;
1061                         }
1062 
1063                         /* create and init array for received can_frames */
1064                         op->last_frames = kzalloc(msg_head->nframes * CFSIZ,
1065                                                   GFP_KERNEL);
1066                         if (!op->last_frames) {
1067                                 kfree(op->frames);
1068                                 kfree(op);
1069                                 return -ENOMEM;
1070                         }
1071 
1072                 } else {
1073                         op->frames = &op->sframe;
1074                         op->last_frames = &op->last_sframe;
1075                 }
1076 
1077                 if (msg_head->nframes) {
1078                         err = memcpy_fromiovec((u8 *)op->frames, msg->msg_iov,
1079                                                msg_head->nframes * CFSIZ);
1080                         if (err < 0) {
1081                                 if (op->frames != &op->sframe)
1082                                         kfree(op->frames);
1083                                 if (op->last_frames != &op->last_sframe)
1084                                         kfree(op->last_frames);
1085                                 kfree(op);
1086                                 return err;
1087                         }
1088                 }
1089 
1090                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1091                 op->sk = sk;
1092                 op->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, GFP_KERNEL);
1207 
1208         if (!skb)
1209                 return -ENOMEM;
1210 
1211         err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
1212         if (err < 0) {
1213                 kfree_skb(skb);
1214                 return err;
1215         }
1216 
1217         dev = dev_get_by_index(&init_net, ifindex);
1218         if (!dev) {
1219                 kfree_skb(skb);
1220                 return -ENODEV;
1221         }
1222 
1223         skb->dev = dev;
1224         skb->sk  = sk;
1225         err = can_send(skb, 1); /* send with loopback */
1226         dev_put(dev);
1227 
1228         if (err)
1229                 return err;
1230 
1231         return CFSIZ + MHSIZ;
1232 }
1233 
1234 /*
1235  * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1236  */
1237 static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1238                        struct msghdr *msg, size_t size)
1239 {
1240         struct sock *sk = sock->sk;
1241         struct bcm_sock *bo = bcm_sk(sk);
1242         int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1243         struct bcm_msg_head msg_head;
1244         int ret; /* read bytes or error codes as return value */
1245 
1246         if (!bo->bound)
1247                 return -ENOTCONN;
1248 
1249         /* check for valid message length from userspace */
1250         if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1251                 return -EINVAL;
1252 
1253         /* check for alternative ifindex for this bcm_op */
1254 
1255         if (!ifindex && msg->msg_name) {
1256                 /* no bound device as default => check msg_name */
1257                 struct sockaddr_can *addr =
1258                         (struct sockaddr_can *)msg->msg_name;
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 (bo->bound)
1500                 return -EISCONN;
1501 
1502         /* bind a device to this socket */
1503         if (addr->can_ifindex) {
1504                 struct net_device *dev;
1505 
1506                 dev = dev_get_by_index(&init_net, addr->can_ifindex);
1507                 if (!dev)
1508                         return -ENODEV;
1509 
1510                 if (dev->type != ARPHRD_CAN) {
1511                         dev_put(dev);
1512                         return -ENODEV;
1513                 }
1514 
1515                 bo->ifindex = dev->ifindex;
1516                 dev_put(dev);
1517 
1518         } else {
1519                 /* no interface reference for ifindex = 0 ('any' CAN device) */
1520                 bo->ifindex = 0;
1521         }
1522 
1523         bo->bound = 1;
1524 
1525         if (proc_dir) {
1526                 /* unique socket address as filename */
1527                 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1528                 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1529                                                      proc_dir,
1530                                                      &bcm_proc_fops, sk);
1531         }
1532 
1533         return 0;
1534 }
1535 
1536 static int bcm_recvmsg(struct kiocb *iocb, struct socket *sock,
1537                        struct msghdr *msg, size_t size, int flags)
1538 {
1539         struct sock *sk = sock->sk;
1540         struct sk_buff *skb;
1541         int error = 0;
1542         int noblock;
1543         int err;
1544 
1545         noblock =  flags & MSG_DONTWAIT;
1546         flags   &= ~MSG_DONTWAIT;
1547         skb = skb_recv_datagram(sk, flags, noblock, &error);
1548         if (!skb)
1549                 return error;
1550 
1551         if (skb->len < size)
1552                 size = skb->len;
1553 
1554         err = memcpy_toiovec(msg->msg_iov, skb->data, size);
1555         if (err < 0) {
1556                 skb_free_datagram(sk, skb);
1557                 return err;
1558         }
1559 
1560         sock_recv_timestamp(msg, sk, skb);
1561 
1562         if (msg->msg_name) {
1563                 msg->msg_namelen = sizeof(struct sockaddr_can);
1564                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1565         }
1566 
1567         skb_free_datagram(sk, skb);
1568 
1569         return size;
1570 }
1571 
1572 static struct proto_ops bcm_ops __read_mostly = {
1573         .family        = PF_CAN,
1574         .release       = bcm_release,
1575         .bind          = sock_no_bind,
1576         .connect       = bcm_connect,
1577         .socketpair    = sock_no_socketpair,
1578         .accept        = sock_no_accept,
1579         .getname       = sock_no_getname,
1580         .poll          = datagram_poll,
1581         .ioctl         = NULL,          /* use can_ioctl() from af_can.c */
1582         .listen        = sock_no_listen,
1583         .shutdown      = sock_no_shutdown,
1584         .setsockopt    = sock_no_setsockopt,
1585         .getsockopt    = sock_no_getsockopt,
1586         .sendmsg       = bcm_sendmsg,
1587         .recvmsg       = bcm_recvmsg,
1588         .mmap          = sock_no_mmap,
1589         .sendpage      = sock_no_sendpage,
1590 };
1591 
1592 static struct proto bcm_proto __read_mostly = {
1593         .name       = "CAN_BCM",
1594         .owner      = THIS_MODULE,
1595         .obj_size   = sizeof(struct bcm_sock),
1596         .init       = bcm_init,
1597 };
1598 
1599 static struct can_proto bcm_can_proto __read_mostly = {
1600         .type       = SOCK_DGRAM,
1601         .protocol   = CAN_BCM,
1602         .capability = -1,
1603         .ops        = &bcm_ops,
1604         .prot       = &bcm_proto,
1605 };
1606 
1607 static int __init bcm_module_init(void)
1608 {
1609         int err;
1610 
1611         printk(banner);
1612 
1613         err = can_proto_register(&bcm_can_proto);
1614         if (err < 0) {
1615                 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1616                 return err;
1617         }
1618 
1619         /* create /proc/net/can-bcm directory */
1620         proc_dir = proc_mkdir("can-bcm", init_net.proc_net);
1621         return 0;
1622 }
1623 
1624 static void __exit bcm_module_exit(void)
1625 {
1626         can_proto_unregister(&bcm_can_proto);
1627 
1628         if (proc_dir)
1629                 proc_net_remove(&init_net, "can-bcm");
1630 }
1631 
1632 module_init(bcm_module_init);
1633 module_exit(bcm_module_exit);
1634 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp