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

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

Version: ~ [ linux-4.15-rc8 ] ~ [ linux-4.14.13 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.76 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.111 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.48 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.91 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.53 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.98 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.27.62 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ 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) 2002-2017 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].flags */
 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_FLAGS_MASK 0x3F /* to clean private flags after usage */
 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 "20170425"
 81 
 82 MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
 83 MODULE_LICENSE("Dual BSD/GPL");
 84 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
 85 MODULE_ALIAS("can-proto-2");
 86 
 87 /*
 88  * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
 89  * 64 bit aligned so the offset has to be multiples of 8 which is ensured
 90  * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
 91  */
 92 static inline u64 get_u64(const struct canfd_frame *cp, int offset)
 93 {
 94         return *(u64 *)(cp->data + offset);
 95 }
 96 
 97 struct bcm_op {
 98         struct list_head list;
 99         int ifindex;
100         canid_t can_id;
101         u32 flags;
102         unsigned long frames_abs, frames_filtered;
103         struct bcm_timeval ival1, ival2;
104         struct hrtimer timer, thrtimer;
105         struct tasklet_struct tsklet, thrtsklet;
106         ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
107         int rx_ifindex;
108         int cfsiz;
109         u32 count;
110         u32 nframes;
111         u32 currframe;
112         /* void pointers to arrays of struct can[fd]_frame */
113         void *frames;
114         void *last_frames;
115         struct canfd_frame sframe;
116         struct canfd_frame last_sframe;
117         struct sock *sk;
118         struct net_device *rx_reg_dev;
119 };
120 
121 struct bcm_sock {
122         struct sock sk;
123         int bound;
124         int ifindex;
125         struct notifier_block notifier;
126         struct list_head rx_ops;
127         struct list_head tx_ops;
128         unsigned long dropped_usr_msgs;
129         struct proc_dir_entry *bcm_proc_read;
130         char procname [32]; /* inode number in decimal with \0 */
131 };
132 
133 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
134 {
135         return (struct bcm_sock *)sk;
136 }
137 
138 static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
139 {
140         return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
141 }
142 
143 #define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
144 #define OPSIZ sizeof(struct bcm_op)
145 #define MHSIZ sizeof(struct bcm_msg_head)
146 
147 /*
148  * procfs functions
149  */
150 #if IS_ENABLED(CONFIG_PROC_FS)
151 static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
152 {
153         struct net_device *dev;
154 
155         if (!ifindex)
156                 return "any";
157 
158         rcu_read_lock();
159         dev = dev_get_by_index_rcu(net, ifindex);
160         if (dev)
161                 strcpy(result, dev->name);
162         else
163                 strcpy(result, "???");
164         rcu_read_unlock();
165 
166         return result;
167 }
168 
169 static int bcm_proc_show(struct seq_file *m, void *v)
170 {
171         char ifname[IFNAMSIZ];
172         struct net *net = m->private;
173         struct sock *sk = (struct sock *)PDE_DATA(m->file->f_inode);
174         struct bcm_sock *bo = bcm_sk(sk);
175         struct bcm_op *op;
176 
177         seq_printf(m, ">>> socket %pK", sk->sk_socket);
178         seq_printf(m, " / sk %pK", sk);
179         seq_printf(m, " / bo %pK", bo);
180         seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
181         seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
182         seq_printf(m, " <<<\n");
183 
184         list_for_each_entry(op, &bo->rx_ops, list) {
185 
186                 unsigned long reduction;
187 
188                 /* print only active entries & prevent division by zero */
189                 if (!op->frames_abs)
190                         continue;
191 
192                 seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
193                            bcm_proc_getifname(net, ifname, op->ifindex));
194 
195                 if (op->flags & CAN_FD_FRAME)
196                         seq_printf(m, "(%u)", op->nframes);
197                 else
198                         seq_printf(m, "[%u]", op->nframes);
199 
200                 seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
201 
202                 if (op->kt_ival1)
203                         seq_printf(m, "timeo=%lld ",
204                                    (long long)ktime_to_us(op->kt_ival1));
205 
206                 if (op->kt_ival2)
207                         seq_printf(m, "thr=%lld ",
208                                    (long long)ktime_to_us(op->kt_ival2));
209 
210                 seq_printf(m, "# recv %ld (%ld) => reduction: ",
211                            op->frames_filtered, op->frames_abs);
212 
213                 reduction = 100 - (op->frames_filtered * 100) / op->frames_abs;
214 
215                 seq_printf(m, "%s%ld%%\n",
216                            (reduction == 100) ? "near " : "", reduction);
217         }
218 
219         list_for_each_entry(op, &bo->tx_ops, list) {
220 
221                 seq_printf(m, "tx_op: %03X %s ", op->can_id,
222                            bcm_proc_getifname(net, ifname, op->ifindex));
223 
224                 if (op->flags & CAN_FD_FRAME)
225                         seq_printf(m, "(%u) ", op->nframes);
226                 else
227                         seq_printf(m, "[%u] ", op->nframes);
228 
229                 if (op->kt_ival1)
230                         seq_printf(m, "t1=%lld ",
231                                    (long long)ktime_to_us(op->kt_ival1));
232 
233                 if (op->kt_ival2)
234                         seq_printf(m, "t2=%lld ",
235                                    (long long)ktime_to_us(op->kt_ival2));
236 
237                 seq_printf(m, "# sent %ld\n", op->frames_abs);
238         }
239         seq_putc(m, '\n');
240         return 0;
241 }
242 
243 static int bcm_proc_open(struct inode *inode, struct file *file)
244 {
245         return single_open_net(inode, file, bcm_proc_show);
246 }
247 
248 static const struct file_operations bcm_proc_fops = {
249         .owner          = THIS_MODULE,
250         .open           = bcm_proc_open,
251         .read           = seq_read,
252         .llseek         = seq_lseek,
253         .release        = single_release,
254 };
255 #endif /* CONFIG_PROC_FS */
256 
257 /*
258  * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
259  *              of the given bcm tx op
260  */
261 static void bcm_can_tx(struct bcm_op *op)
262 {
263         struct sk_buff *skb;
264         struct net_device *dev;
265         struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
266 
267         /* no target device? => exit */
268         if (!op->ifindex)
269                 return;
270 
271         dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
272         if (!dev) {
273                 /* RFC: should this bcm_op remove itself here? */
274                 return;
275         }
276 
277         skb = alloc_skb(op->cfsiz + sizeof(struct can_skb_priv), gfp_any());
278         if (!skb)
279                 goto out;
280 
281         can_skb_reserve(skb);
282         can_skb_prv(skb)->ifindex = dev->ifindex;
283         can_skb_prv(skb)->skbcnt = 0;
284 
285         skb_put_data(skb, cf, op->cfsiz);
286 
287         /* send with loopback */
288         skb->dev = dev;
289         can_skb_set_owner(skb, op->sk);
290         can_send(skb, 1);
291 
292         /* update statistics */
293         op->currframe++;
294         op->frames_abs++;
295 
296         /* reached last frame? */
297         if (op->currframe >= op->nframes)
298                 op->currframe = 0;
299 out:
300         dev_put(dev);
301 }
302 
303 /*
304  * bcm_send_to_user - send a BCM message to the userspace
305  *                    (consisting of bcm_msg_head + x CAN frames)
306  */
307 static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
308                              struct canfd_frame *frames, int has_timestamp)
309 {
310         struct sk_buff *skb;
311         struct canfd_frame *firstframe;
312         struct sockaddr_can *addr;
313         struct sock *sk = op->sk;
314         unsigned int datalen = head->nframes * op->cfsiz;
315         int err;
316 
317         skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
318         if (!skb)
319                 return;
320 
321         skb_put_data(skb, head, sizeof(*head));
322 
323         if (head->nframes) {
324                 /* CAN frames starting here */
325                 firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
326 
327                 skb_put_data(skb, frames, datalen);
328 
329                 /*
330                  * the BCM uses the flags-element of the canfd_frame
331                  * structure for internal purposes. This is only
332                  * relevant for updates that are generated by the
333                  * BCM, where nframes is 1
334                  */
335                 if (head->nframes == 1)
336                         firstframe->flags &= BCM_CAN_FLAGS_MASK;
337         }
338 
339         if (has_timestamp) {
340                 /* restore rx timestamp */
341                 skb->tstamp = op->rx_stamp;
342         }
343 
344         /*
345          *  Put the datagram to the queue so that bcm_recvmsg() can
346          *  get it from there.  We need to pass the interface index to
347          *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
348          *  containing the interface index.
349          */
350 
351         sock_skb_cb_check_size(sizeof(struct sockaddr_can));
352         addr = (struct sockaddr_can *)skb->cb;
353         memset(addr, 0, sizeof(*addr));
354         addr->can_family  = AF_CAN;
355         addr->can_ifindex = op->rx_ifindex;
356 
357         err = sock_queue_rcv_skb(sk, skb);
358         if (err < 0) {
359                 struct bcm_sock *bo = bcm_sk(sk);
360 
361                 kfree_skb(skb);
362                 /* don't care about overflows in this statistic */
363                 bo->dropped_usr_msgs++;
364         }
365 }
366 
367 static void bcm_tx_start_timer(struct bcm_op *op)
368 {
369         if (op->kt_ival1 && op->count)
370                 hrtimer_start(&op->timer,
371                               ktime_add(ktime_get(), op->kt_ival1),
372                               HRTIMER_MODE_ABS);
373         else if (op->kt_ival2)
374                 hrtimer_start(&op->timer,
375                               ktime_add(ktime_get(), op->kt_ival2),
376                               HRTIMER_MODE_ABS);
377 }
378 
379 static void bcm_tx_timeout_tsklet(unsigned long data)
380 {
381         struct bcm_op *op = (struct bcm_op *)data;
382         struct bcm_msg_head msg_head;
383 
384         if (op->kt_ival1 && (op->count > 0)) {
385 
386                 op->count--;
387                 if (!op->count && (op->flags & TX_COUNTEVT)) {
388 
389                         /* create notification to user */
390                         msg_head.opcode  = TX_EXPIRED;
391                         msg_head.flags   = op->flags;
392                         msg_head.count   = op->count;
393                         msg_head.ival1   = op->ival1;
394                         msg_head.ival2   = op->ival2;
395                         msg_head.can_id  = op->can_id;
396                         msg_head.nframes = 0;
397 
398                         bcm_send_to_user(op, &msg_head, NULL, 0);
399                 }
400                 bcm_can_tx(op);
401 
402         } else if (op->kt_ival2)
403                 bcm_can_tx(op);
404 
405         bcm_tx_start_timer(op);
406 }
407 
408 /*
409  * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions
410  */
411 static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
412 {
413         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
414 
415         tasklet_schedule(&op->tsklet);
416 
417         return HRTIMER_NORESTART;
418 }
419 
420 /*
421  * bcm_rx_changed - create a RX_CHANGED notification due to changed content
422  */
423 static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
424 {
425         struct bcm_msg_head head;
426 
427         /* update statistics */
428         op->frames_filtered++;
429 
430         /* prevent statistics overflow */
431         if (op->frames_filtered > ULONG_MAX/100)
432                 op->frames_filtered = op->frames_abs = 0;
433 
434         /* this element is not throttled anymore */
435         data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
436 
437         head.opcode  = RX_CHANGED;
438         head.flags   = op->flags;
439         head.count   = op->count;
440         head.ival1   = op->ival1;
441         head.ival2   = op->ival2;
442         head.can_id  = op->can_id;
443         head.nframes = 1;
444 
445         bcm_send_to_user(op, &head, data, 1);
446 }
447 
448 /*
449  * bcm_rx_update_and_send - process a detected relevant receive content change
450  *                          1. update the last received data
451  *                          2. send a notification to the user (if possible)
452  */
453 static void bcm_rx_update_and_send(struct bcm_op *op,
454                                    struct canfd_frame *lastdata,
455                                    const struct canfd_frame *rxdata)
456 {
457         memcpy(lastdata, rxdata, op->cfsiz);
458 
459         /* mark as used and throttled by default */
460         lastdata->flags |= (RX_RECV|RX_THR);
461 
462         /* throttling mode inactive ? */
463         if (!op->kt_ival2) {
464                 /* send RX_CHANGED to the user immediately */
465                 bcm_rx_changed(op, lastdata);
466                 return;
467         }
468 
469         /* with active throttling timer we are just done here */
470         if (hrtimer_active(&op->thrtimer))
471                 return;
472 
473         /* first reception with enabled throttling mode */
474         if (!op->kt_lastmsg)
475                 goto rx_changed_settime;
476 
477         /* got a second frame inside a potential throttle period? */
478         if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
479             ktime_to_us(op->kt_ival2)) {
480                 /* do not send the saved data - only start throttle timer */
481                 hrtimer_start(&op->thrtimer,
482                               ktime_add(op->kt_lastmsg, op->kt_ival2),
483                               HRTIMER_MODE_ABS);
484                 return;
485         }
486 
487         /* the gap was that big, that throttling was not needed here */
488 rx_changed_settime:
489         bcm_rx_changed(op, lastdata);
490         op->kt_lastmsg = ktime_get();
491 }
492 
493 /*
494  * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
495  *                       received data stored in op->last_frames[]
496  */
497 static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
498                                 const struct canfd_frame *rxdata)
499 {
500         struct canfd_frame *cf = op->frames + op->cfsiz * index;
501         struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
502         int i;
503 
504         /*
505          * no one uses the MSBs of flags for comparison,
506          * so we use it here to detect the first time of reception
507          */
508 
509         if (!(lcf->flags & RX_RECV)) {
510                 /* received data for the first time => send update to user */
511                 bcm_rx_update_and_send(op, lcf, rxdata);
512                 return;
513         }
514 
515         /* do a real check in CAN frame data section */
516         for (i = 0; i < rxdata->len; i += 8) {
517                 if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
518                     (get_u64(cf, i) & get_u64(lcf, i))) {
519                         bcm_rx_update_and_send(op, lcf, rxdata);
520                         return;
521                 }
522         }
523 
524         if (op->flags & RX_CHECK_DLC) {
525                 /* do a real check in CAN frame length */
526                 if (rxdata->len != lcf->len) {
527                         bcm_rx_update_and_send(op, lcf, rxdata);
528                         return;
529                 }
530         }
531 }
532 
533 /*
534  * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
535  */
536 static void bcm_rx_starttimer(struct bcm_op *op)
537 {
538         if (op->flags & RX_NO_AUTOTIMER)
539                 return;
540 
541         if (op->kt_ival1)
542                 hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL);
543 }
544 
545 static void bcm_rx_timeout_tsklet(unsigned long data)
546 {
547         struct bcm_op *op = (struct bcm_op *)data;
548         struct bcm_msg_head msg_head;
549 
550         /* create notification to user */
551         msg_head.opcode  = RX_TIMEOUT;
552         msg_head.flags   = op->flags;
553         msg_head.count   = op->count;
554         msg_head.ival1   = op->ival1;
555         msg_head.ival2   = op->ival2;
556         msg_head.can_id  = op->can_id;
557         msg_head.nframes = 0;
558 
559         bcm_send_to_user(op, &msg_head, NULL, 0);
560 }
561 
562 /*
563  * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out
564  */
565 static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
566 {
567         struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
568 
569         /* schedule before NET_RX_SOFTIRQ */
570         tasklet_hi_schedule(&op->tsklet);
571 
572         /* no restart of the timer is done here! */
573 
574         /* if user wants to be informed, when cyclic CAN-Messages come back */
575         if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
576                 /* clear received CAN frames to indicate 'nothing received' */
577                 memset(op->last_frames, 0, op->nframes * op->cfsiz);
578         }
579 
580         return HRTIMER_NORESTART;
581 }
582 
583 /*
584  * bcm_rx_do_flush - helper for bcm_rx_thr_flush
585  */
586 static inline int bcm_rx_do_flush(struct bcm_op *op, int update,
587                                   unsigned int index)
588 {
589         struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
590 
591         if ((op->last_frames) && (lcf->flags & RX_THR)) {
592                 if (update)
593                         bcm_rx_changed(op, lcf);
594                 return 1;
595         }
596         return 0;
597 }
598 
599 /*
600  * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
601  *
602  * update == 0 : just check if throttled data is available  (any irq context)
603  * update == 1 : check and send throttled data to userspace (soft_irq context)
604  */
605 static int bcm_rx_thr_flush(struct bcm_op *op, int update)
606 {
607         int updated = 0;
608 
609         if (op->nframes > 1) {
610                 unsigned int i;
611 
612                 /* for MUX filter we start at index 1 */
613                 for (i = 1; i < op->nframes; i++)
614                         updated += bcm_rx_do_flush(op, update, i);
615 
616         } else {
617                 /* for RX_FILTER_ID and simple filter */
618                 updated += bcm_rx_do_flush(op, update, 0);
619         }
620 
621         return updated;
622 }
623 
624 static void bcm_rx_thr_tsklet(unsigned long data)
625 {
626         struct bcm_op *op = (struct bcm_op *)data;
627 
628         /* push the changed data to the userspace */
629         bcm_rx_thr_flush(op, 1);
630 }
631 
632 /*
633  * bcm_rx_thr_handler - the time for blocked content updates is over now:
634  *                      Check for throttled data and send it to the userspace
635  */
636 static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
637 {
638         struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
639 
640         tasklet_schedule(&op->thrtsklet);
641 
642         if (bcm_rx_thr_flush(op, 0)) {
643                 hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2);
644                 return HRTIMER_RESTART;
645         } else {
646                 /* rearm throttle handling */
647                 op->kt_lastmsg = 0;
648                 return HRTIMER_NORESTART;
649         }
650 }
651 
652 /*
653  * bcm_rx_handler - handle a CAN frame reception
654  */
655 static void bcm_rx_handler(struct sk_buff *skb, void *data)
656 {
657         struct bcm_op *op = (struct bcm_op *)data;
658         const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
659         unsigned int i;
660 
661         if (op->can_id != rxframe->can_id)
662                 return;
663 
664         /* make sure to handle the correct frame type (CAN / CAN FD) */
665         if (skb->len != op->cfsiz)
666                 return;
667 
668         /* disable timeout */
669         hrtimer_cancel(&op->timer);
670 
671         /* save rx timestamp */
672         op->rx_stamp = skb->tstamp;
673         /* save originator for recvfrom() */
674         op->rx_ifindex = skb->dev->ifindex;
675         /* update statistics */
676         op->frames_abs++;
677 
678         if (op->flags & RX_RTR_FRAME) {
679                 /* send reply for RTR-request (placed in op->frames[0]) */
680                 bcm_can_tx(op);
681                 return;
682         }
683 
684         if (op->flags & RX_FILTER_ID) {
685                 /* the easiest case */
686                 bcm_rx_update_and_send(op, op->last_frames, rxframe);
687                 goto rx_starttimer;
688         }
689 
690         if (op->nframes == 1) {
691                 /* simple compare with index 0 */
692                 bcm_rx_cmp_to_index(op, 0, rxframe);
693                 goto rx_starttimer;
694         }
695 
696         if (op->nframes > 1) {
697                 /*
698                  * multiplex compare
699                  *
700                  * find the first multiplex mask that fits.
701                  * Remark: The MUX-mask is stored in index 0 - but only the
702                  * first 64 bits of the frame data[] are relevant (CAN FD)
703                  */
704 
705                 for (i = 1; i < op->nframes; i++) {
706                         if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
707                             (get_u64(op->frames, 0) &
708                              get_u64(op->frames + op->cfsiz * i, 0))) {
709                                 bcm_rx_cmp_to_index(op, i, rxframe);
710                                 break;
711                         }
712                 }
713         }
714 
715 rx_starttimer:
716         bcm_rx_starttimer(op);
717 }
718 
719 /*
720  * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
721  */
722 static struct bcm_op *bcm_find_op(struct list_head *ops,
723                                   struct bcm_msg_head *mh, int ifindex)
724 {
725         struct bcm_op *op;
726 
727         list_for_each_entry(op, ops, list) {
728                 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
729                     (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
730                         return op;
731         }
732 
733         return NULL;
734 }
735 
736 static void bcm_remove_op(struct bcm_op *op)
737 {
738         if (op->tsklet.func) {
739                 while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
740                        test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
741                        hrtimer_active(&op->timer)) {
742                         hrtimer_cancel(&op->timer);
743                         tasklet_kill(&op->tsklet);
744                 }
745         }
746 
747         if (op->thrtsklet.func) {
748                 while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
749                        test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
750                        hrtimer_active(&op->thrtimer)) {
751                         hrtimer_cancel(&op->thrtimer);
752                         tasklet_kill(&op->thrtsklet);
753                 }
754         }
755 
756         if ((op->frames) && (op->frames != &op->sframe))
757                 kfree(op->frames);
758 
759         if ((op->last_frames) && (op->last_frames != &op->last_sframe))
760                 kfree(op->last_frames);
761 
762         kfree(op);
763 }
764 
765 static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
766 {
767         if (op->rx_reg_dev == dev) {
768                 can_rx_unregister(dev_net(dev), dev, op->can_id,
769                                   REGMASK(op->can_id), bcm_rx_handler, op);
770 
771                 /* mark as removed subscription */
772                 op->rx_reg_dev = NULL;
773         } else
774                 printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
775                        "mismatch %p %p\n", op->rx_reg_dev, dev);
776 }
777 
778 /*
779  * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
780  */
781 static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
782                             int ifindex)
783 {
784         struct bcm_op *op, *n;
785 
786         list_for_each_entry_safe(op, n, ops, list) {
787                 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
788                     (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
789 
790                         /*
791                          * Don't care if we're bound or not (due to netdev
792                          * problems) can_rx_unregister() is always a save
793                          * thing to do here.
794                          */
795                         if (op->ifindex) {
796                                 /*
797                                  * Only remove subscriptions that had not
798                                  * been removed due to NETDEV_UNREGISTER
799                                  * in bcm_notifier()
800                                  */
801                                 if (op->rx_reg_dev) {
802                                         struct net_device *dev;
803 
804                                         dev = dev_get_by_index(sock_net(op->sk),
805                                                                op->ifindex);
806                                         if (dev) {
807                                                 bcm_rx_unreg(dev, op);
808                                                 dev_put(dev);
809                                         }
810                                 }
811                         } else
812                                 can_rx_unregister(sock_net(op->sk), NULL,
813                                                   op->can_id,
814                                                   REGMASK(op->can_id),
815                                                   bcm_rx_handler, op);
816 
817                         list_del(&op->list);
818                         bcm_remove_op(op);
819                         return 1; /* done */
820                 }
821         }
822 
823         return 0; /* not found */
824 }
825 
826 /*
827  * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
828  */
829 static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
830                             int ifindex)
831 {
832         struct bcm_op *op, *n;
833 
834         list_for_each_entry_safe(op, n, ops, list) {
835                 if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
836                     (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
837                         list_del(&op->list);
838                         bcm_remove_op(op);
839                         return 1; /* done */
840                 }
841         }
842 
843         return 0; /* not found */
844 }
845 
846 /*
847  * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
848  */
849 static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
850                        int ifindex)
851 {
852         struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
853 
854         if (!op)
855                 return -EINVAL;
856 
857         /* put current values into msg_head */
858         msg_head->flags   = op->flags;
859         msg_head->count   = op->count;
860         msg_head->ival1   = op->ival1;
861         msg_head->ival2   = op->ival2;
862         msg_head->nframes = op->nframes;
863 
864         bcm_send_to_user(op, msg_head, op->frames, 0);
865 
866         return MHSIZ;
867 }
868 
869 /*
870  * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
871  */
872 static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
873                         int ifindex, struct sock *sk)
874 {
875         struct bcm_sock *bo = bcm_sk(sk);
876         struct bcm_op *op;
877         struct canfd_frame *cf;
878         unsigned int i;
879         int err;
880 
881         /* we need a real device to send frames */
882         if (!ifindex)
883                 return -ENODEV;
884 
885         /* check nframes boundaries - we need at least one CAN frame */
886         if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
887                 return -EINVAL;
888 
889         /* check the given can_id */
890         op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
891         if (op) {
892                 /* update existing BCM operation */
893 
894                 /*
895                  * Do we need more space for the CAN frames than currently
896                  * allocated? -> This is a _really_ unusual use-case and
897                  * therefore (complexity / locking) it is not supported.
898                  */
899                 if (msg_head->nframes > op->nframes)
900                         return -E2BIG;
901 
902                 /* update CAN frames content */
903                 for (i = 0; i < msg_head->nframes; i++) {
904 
905                         cf = op->frames + op->cfsiz * i;
906                         err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
907 
908                         if (op->flags & CAN_FD_FRAME) {
909                                 if (cf->len > 64)
910                                         err = -EINVAL;
911                         } else {
912                                 if (cf->len > 8)
913                                         err = -EINVAL;
914                         }
915 
916                         if (err < 0)
917                                 return err;
918 
919                         if (msg_head->flags & TX_CP_CAN_ID) {
920                                 /* copy can_id into frame */
921                                 cf->can_id = msg_head->can_id;
922                         }
923                 }
924                 op->flags = msg_head->flags;
925 
926         } else {
927                 /* insert new BCM operation for the given can_id */
928 
929                 op = kzalloc(OPSIZ, GFP_KERNEL);
930                 if (!op)
931                         return -ENOMEM;
932 
933                 op->can_id = msg_head->can_id;
934                 op->cfsiz = CFSIZ(msg_head->flags);
935                 op->flags = msg_head->flags;
936 
937                 /* create array for CAN frames and copy the data */
938                 if (msg_head->nframes > 1) {
939                         op->frames = kmalloc(msg_head->nframes * op->cfsiz,
940                                              GFP_KERNEL);
941                         if (!op->frames) {
942                                 kfree(op);
943                                 return -ENOMEM;
944                         }
945                 } else
946                         op->frames = &op->sframe;
947 
948                 for (i = 0; i < msg_head->nframes; i++) {
949 
950                         cf = op->frames + op->cfsiz * i;
951                         err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
952 
953                         if (op->flags & CAN_FD_FRAME) {
954                                 if (cf->len > 64)
955                                         err = -EINVAL;
956                         } else {
957                                 if (cf->len > 8)
958                                         err = -EINVAL;
959                         }
960 
961                         if (err < 0) {
962                                 if (op->frames != &op->sframe)
963                                         kfree(op->frames);
964                                 kfree(op);
965                                 return err;
966                         }
967 
968                         if (msg_head->flags & TX_CP_CAN_ID) {
969                                 /* copy can_id into frame */
970                                 cf->can_id = msg_head->can_id;
971                         }
972                 }
973 
974                 /* tx_ops never compare with previous received messages */
975                 op->last_frames = NULL;
976 
977                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
978                 op->sk = sk;
979                 op->ifindex = ifindex;
980 
981                 /* initialize uninitialized (kzalloc) structure */
982                 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
983                 op->timer.function = bcm_tx_timeout_handler;
984 
985                 /* initialize tasklet for tx countevent notification */
986                 tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet,
987                              (unsigned long) op);
988 
989                 /* currently unused in tx_ops */
990                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
991 
992                 /* add this bcm_op to the list of the tx_ops */
993                 list_add(&op->list, &bo->tx_ops);
994 
995         } /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
996 
997         if (op->nframes != msg_head->nframes) {
998                 op->nframes   = msg_head->nframes;
999                 /* start multiple frame transmission with index 0 */
1000                 op->currframe = 0;
1001         }
1002 
1003         /* check flags */
1004 
1005         if (op->flags & TX_RESET_MULTI_IDX) {
1006                 /* start multiple frame transmission with index 0 */
1007                 op->currframe = 0;
1008         }
1009 
1010         if (op->flags & SETTIMER) {
1011                 /* set timer values */
1012                 op->count = msg_head->count;
1013                 op->ival1 = msg_head->ival1;
1014                 op->ival2 = msg_head->ival2;
1015                 op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1016                 op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1017 
1018                 /* disable an active timer due to zero values? */
1019                 if (!op->kt_ival1 && !op->kt_ival2)
1020                         hrtimer_cancel(&op->timer);
1021         }
1022 
1023         if (op->flags & STARTTIMER) {
1024                 hrtimer_cancel(&op->timer);
1025                 /* spec: send CAN frame when starting timer */
1026                 op->flags |= TX_ANNOUNCE;
1027         }
1028 
1029         if (op->flags & TX_ANNOUNCE) {
1030                 bcm_can_tx(op);
1031                 if (op->count)
1032                         op->count--;
1033         }
1034 
1035         if (op->flags & STARTTIMER)
1036                 bcm_tx_start_timer(op);
1037 
1038         return msg_head->nframes * op->cfsiz + MHSIZ;
1039 }
1040 
1041 /*
1042  * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
1043  */
1044 static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
1045                         int ifindex, struct sock *sk)
1046 {
1047         struct bcm_sock *bo = bcm_sk(sk);
1048         struct bcm_op *op;
1049         int do_rx_register;
1050         int err = 0;
1051 
1052         if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
1053                 /* be robust against wrong usage ... */
1054                 msg_head->flags |= RX_FILTER_ID;
1055                 /* ignore trailing garbage */
1056                 msg_head->nframes = 0;
1057         }
1058 
1059         /* the first element contains the mux-mask => MAX_NFRAMES + 1  */
1060         if (msg_head->nframes > MAX_NFRAMES + 1)
1061                 return -EINVAL;
1062 
1063         if ((msg_head->flags & RX_RTR_FRAME) &&
1064             ((msg_head->nframes != 1) ||
1065              (!(msg_head->can_id & CAN_RTR_FLAG))))
1066                 return -EINVAL;
1067 
1068         /* check the given can_id */
1069         op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
1070         if (op) {
1071                 /* update existing BCM operation */
1072 
1073                 /*
1074                  * Do we need more space for the CAN frames than currently
1075                  * allocated? -> This is a _really_ unusual use-case and
1076                  * therefore (complexity / locking) it is not supported.
1077                  */
1078                 if (msg_head->nframes > op->nframes)
1079                         return -E2BIG;
1080 
1081                 if (msg_head->nframes) {
1082                         /* update CAN frames content */
1083                         err = memcpy_from_msg(op->frames, msg,
1084                                               msg_head->nframes * op->cfsiz);
1085                         if (err < 0)
1086                                 return err;
1087 
1088                         /* clear last_frames to indicate 'nothing received' */
1089                         memset(op->last_frames, 0, msg_head->nframes * op->cfsiz);
1090                 }
1091 
1092                 op->nframes = msg_head->nframes;
1093                 op->flags = msg_head->flags;
1094 
1095                 /* Only an update -> do not call can_rx_register() */
1096                 do_rx_register = 0;
1097 
1098         } else {
1099                 /* insert new BCM operation for the given can_id */
1100                 op = kzalloc(OPSIZ, GFP_KERNEL);
1101                 if (!op)
1102                         return -ENOMEM;
1103 
1104                 op->can_id = msg_head->can_id;
1105                 op->nframes = msg_head->nframes;
1106                 op->cfsiz = CFSIZ(msg_head->flags);
1107                 op->flags = msg_head->flags;
1108 
1109                 if (msg_head->nframes > 1) {
1110                         /* create array for CAN frames and copy the data */
1111                         op->frames = kmalloc(msg_head->nframes * op->cfsiz,
1112                                              GFP_KERNEL);
1113                         if (!op->frames) {
1114                                 kfree(op);
1115                                 return -ENOMEM;
1116                         }
1117 
1118                         /* create and init array for received CAN frames */
1119                         op->last_frames = kzalloc(msg_head->nframes * op->cfsiz,
1120                                                   GFP_KERNEL);
1121                         if (!op->last_frames) {
1122                                 kfree(op->frames);
1123                                 kfree(op);
1124                                 return -ENOMEM;
1125                         }
1126 
1127                 } else {
1128                         op->frames = &op->sframe;
1129                         op->last_frames = &op->last_sframe;
1130                 }
1131 
1132                 if (msg_head->nframes) {
1133                         err = memcpy_from_msg(op->frames, msg,
1134                                               msg_head->nframes * op->cfsiz);
1135                         if (err < 0) {
1136                                 if (op->frames != &op->sframe)
1137                                         kfree(op->frames);
1138                                 if (op->last_frames != &op->last_sframe)
1139                                         kfree(op->last_frames);
1140                                 kfree(op);
1141                                 return err;
1142                         }
1143                 }
1144 
1145                 /* bcm_can_tx / bcm_tx_timeout_handler needs this */
1146                 op->sk = sk;
1147                 op->ifindex = ifindex;
1148 
1149                 /* ifindex for timeout events w/o previous frame reception */
1150                 op->rx_ifindex = ifindex;
1151 
1152                 /* initialize uninitialized (kzalloc) structure */
1153                 hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1154                 op->timer.function = bcm_rx_timeout_handler;
1155 
1156                 /* initialize tasklet for rx timeout notification */
1157                 tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet,
1158                              (unsigned long) op);
1159 
1160                 hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1161                 op->thrtimer.function = bcm_rx_thr_handler;
1162 
1163                 /* initialize tasklet for rx throttle handling */
1164                 tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet,
1165                              (unsigned long) op);
1166 
1167                 /* add this bcm_op to the list of the rx_ops */
1168                 list_add(&op->list, &bo->rx_ops);
1169 
1170                 /* call can_rx_register() */
1171                 do_rx_register = 1;
1172 
1173         } /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
1174 
1175         /* check flags */
1176 
1177         if (op->flags & RX_RTR_FRAME) {
1178                 struct canfd_frame *frame0 = op->frames;
1179 
1180                 /* no timers in RTR-mode */
1181                 hrtimer_cancel(&op->thrtimer);
1182                 hrtimer_cancel(&op->timer);
1183 
1184                 /*
1185                  * funny feature in RX(!)_SETUP only for RTR-mode:
1186                  * copy can_id into frame BUT without RTR-flag to
1187                  * prevent a full-load-loopback-test ... ;-]
1188                  */
1189                 if ((op->flags & TX_CP_CAN_ID) ||
1190                     (frame0->can_id == op->can_id))
1191                         frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
1192 
1193         } else {
1194                 if (op->flags & SETTIMER) {
1195 
1196                         /* set timer value */
1197                         op->ival1 = msg_head->ival1;
1198                         op->ival2 = msg_head->ival2;
1199                         op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
1200                         op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
1201 
1202                         /* disable an active timer due to zero value? */
1203                         if (!op->kt_ival1)
1204                                 hrtimer_cancel(&op->timer);
1205 
1206                         /*
1207                          * In any case cancel the throttle timer, flush
1208                          * potentially blocked msgs and reset throttle handling
1209                          */
1210                         op->kt_lastmsg = 0;
1211                         hrtimer_cancel(&op->thrtimer);
1212                         bcm_rx_thr_flush(op, 1);
1213                 }
1214 
1215                 if ((op->flags & STARTTIMER) && op->kt_ival1)
1216                         hrtimer_start(&op->timer, op->kt_ival1,
1217                                       HRTIMER_MODE_REL);
1218         }
1219 
1220         /* now we can register for can_ids, if we added a new bcm_op */
1221         if (do_rx_register) {
1222                 if (ifindex) {
1223                         struct net_device *dev;
1224 
1225                         dev = dev_get_by_index(sock_net(sk), ifindex);
1226                         if (dev) {
1227                                 err = can_rx_register(sock_net(sk), dev,
1228                                                       op->can_id,
1229                                                       REGMASK(op->can_id),
1230                                                       bcm_rx_handler, op,
1231                                                       "bcm", sk);
1232 
1233                                 op->rx_reg_dev = dev;
1234                                 dev_put(dev);
1235                         }
1236 
1237                 } else
1238                         err = can_rx_register(sock_net(sk), NULL, op->can_id,
1239                                               REGMASK(op->can_id),
1240                                               bcm_rx_handler, op, "bcm", sk);
1241                 if (err) {
1242                         /* this bcm rx op is broken -> remove it */
1243                         list_del(&op->list);
1244                         bcm_remove_op(op);
1245                         return err;
1246                 }
1247         }
1248 
1249         return msg_head->nframes * op->cfsiz + MHSIZ;
1250 }
1251 
1252 /*
1253  * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
1254  */
1255 static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
1256                        int cfsiz)
1257 {
1258         struct sk_buff *skb;
1259         struct net_device *dev;
1260         int err;
1261 
1262         /* we need a real device to send frames */
1263         if (!ifindex)
1264                 return -ENODEV;
1265 
1266         skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), GFP_KERNEL);
1267         if (!skb)
1268                 return -ENOMEM;
1269 
1270         can_skb_reserve(skb);
1271 
1272         err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
1273         if (err < 0) {
1274                 kfree_skb(skb);
1275                 return err;
1276         }
1277 
1278         dev = dev_get_by_index(sock_net(sk), ifindex);
1279         if (!dev) {
1280                 kfree_skb(skb);
1281                 return -ENODEV;
1282         }
1283 
1284         can_skb_prv(skb)->ifindex = dev->ifindex;
1285         can_skb_prv(skb)->skbcnt = 0;
1286         skb->dev = dev;
1287         can_skb_set_owner(skb, sk);
1288         err = can_send(skb, 1); /* send with loopback */
1289         dev_put(dev);
1290 
1291         if (err)
1292                 return err;
1293 
1294         return cfsiz + MHSIZ;
1295 }
1296 
1297 /*
1298  * bcm_sendmsg - process BCM commands (opcodes) from the userspace
1299  */
1300 static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
1301 {
1302         struct sock *sk = sock->sk;
1303         struct bcm_sock *bo = bcm_sk(sk);
1304         int ifindex = bo->ifindex; /* default ifindex for this bcm_op */
1305         struct bcm_msg_head msg_head;
1306         int cfsiz;
1307         int ret; /* read bytes or error codes as return value */
1308 
1309         if (!bo->bound)
1310                 return -ENOTCONN;
1311 
1312         /* check for valid message length from userspace */
1313         if (size < MHSIZ)
1314                 return -EINVAL;
1315 
1316         /* read message head information */
1317         ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
1318         if (ret < 0)
1319                 return ret;
1320 
1321         cfsiz = CFSIZ(msg_head.flags);
1322         if ((size - MHSIZ) % cfsiz)
1323                 return -EINVAL;
1324 
1325         /* check for alternative ifindex for this bcm_op */
1326 
1327         if (!ifindex && msg->msg_name) {
1328                 /* no bound device as default => check msg_name */
1329                 DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
1330 
1331                 if (msg->msg_namelen < sizeof(*addr))
1332                         return -EINVAL;
1333 
1334                 if (addr->can_family != AF_CAN)
1335                         return -EINVAL;
1336 
1337                 /* ifindex from sendto() */
1338                 ifindex = addr->can_ifindex;
1339 
1340                 if (ifindex) {
1341                         struct net_device *dev;
1342 
1343                         dev = dev_get_by_index(sock_net(sk), ifindex);
1344                         if (!dev)
1345                                 return -ENODEV;
1346 
1347                         if (dev->type != ARPHRD_CAN) {
1348                                 dev_put(dev);
1349                                 return -ENODEV;
1350                         }
1351 
1352                         dev_put(dev);
1353                 }
1354         }
1355 
1356         lock_sock(sk);
1357 
1358         switch (msg_head.opcode) {
1359 
1360         case TX_SETUP:
1361                 ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
1362                 break;
1363 
1364         case RX_SETUP:
1365                 ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
1366                 break;
1367 
1368         case TX_DELETE:
1369                 if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
1370                         ret = MHSIZ;
1371                 else
1372                         ret = -EINVAL;
1373                 break;
1374 
1375         case RX_DELETE:
1376                 if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
1377                         ret = MHSIZ;
1378                 else
1379                         ret = -EINVAL;
1380                 break;
1381 
1382         case TX_READ:
1383                 /* reuse msg_head for the reply to TX_READ */
1384                 msg_head.opcode  = TX_STATUS;
1385                 ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
1386                 break;
1387 
1388         case RX_READ:
1389                 /* reuse msg_head for the reply to RX_READ */
1390                 msg_head.opcode  = RX_STATUS;
1391                 ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
1392                 break;
1393 
1394         case TX_SEND:
1395                 /* we need exactly one CAN frame behind the msg head */
1396                 if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
1397                         ret = -EINVAL;
1398                 else
1399                         ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
1400                 break;
1401 
1402         default:
1403                 ret = -EINVAL;
1404                 break;
1405         }
1406 
1407         release_sock(sk);
1408 
1409         return ret;
1410 }
1411 
1412 /*
1413  * notification handler for netdevice status changes
1414  */
1415 static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
1416                         void *ptr)
1417 {
1418         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1419         struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
1420         struct sock *sk = &bo->sk;
1421         struct bcm_op *op;
1422         int notify_enodev = 0;
1423 
1424         if (!net_eq(dev_net(dev), sock_net(sk)))
1425                 return NOTIFY_DONE;
1426 
1427         if (dev->type != ARPHRD_CAN)
1428                 return NOTIFY_DONE;
1429 
1430         switch (msg) {
1431 
1432         case NETDEV_UNREGISTER:
1433                 lock_sock(sk);
1434 
1435                 /* remove device specific receive entries */
1436                 list_for_each_entry(op, &bo->rx_ops, list)
1437                         if (op->rx_reg_dev == dev)
1438                                 bcm_rx_unreg(dev, op);
1439 
1440                 /* remove device reference, if this is our bound device */
1441                 if (bo->bound && bo->ifindex == dev->ifindex) {
1442                         bo->bound   = 0;
1443                         bo->ifindex = 0;
1444                         notify_enodev = 1;
1445                 }
1446 
1447                 release_sock(sk);
1448 
1449                 if (notify_enodev) {
1450                         sk->sk_err = ENODEV;
1451                         if (!sock_flag(sk, SOCK_DEAD))
1452                                 sk->sk_error_report(sk);
1453                 }
1454                 break;
1455 
1456         case NETDEV_DOWN:
1457                 if (bo->bound && bo->ifindex == dev->ifindex) {
1458                         sk->sk_err = ENETDOWN;
1459                         if (!sock_flag(sk, SOCK_DEAD))
1460                                 sk->sk_error_report(sk);
1461                 }
1462         }
1463 
1464         return NOTIFY_DONE;
1465 }
1466 
1467 /*
1468  * initial settings for all BCM sockets to be set at socket creation time
1469  */
1470 static int bcm_init(struct sock *sk)
1471 {
1472         struct bcm_sock *bo = bcm_sk(sk);
1473 
1474         bo->bound            = 0;
1475         bo->ifindex          = 0;
1476         bo->dropped_usr_msgs = 0;
1477         bo->bcm_proc_read    = NULL;
1478 
1479         INIT_LIST_HEAD(&bo->tx_ops);
1480         INIT_LIST_HEAD(&bo->rx_ops);
1481 
1482         /* set notifier */
1483         bo->notifier.notifier_call = bcm_notifier;
1484 
1485         register_netdevice_notifier(&bo->notifier);
1486 
1487         return 0;
1488 }
1489 
1490 /*
1491  * standard socket functions
1492  */
1493 static int bcm_release(struct socket *sock)
1494 {
1495         struct sock *sk = sock->sk;
1496         struct net *net;
1497         struct bcm_sock *bo;
1498         struct bcm_op *op, *next;
1499 
1500         if (!sk)
1501                 return 0;
1502 
1503         net = sock_net(sk);
1504         bo = bcm_sk(sk);
1505 
1506         /* remove bcm_ops, timer, rx_unregister(), etc. */
1507 
1508         unregister_netdevice_notifier(&bo->notifier);
1509 
1510         lock_sock(sk);
1511 
1512         list_for_each_entry_safe(op, next, &bo->tx_ops, list)
1513                 bcm_remove_op(op);
1514 
1515         list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
1516                 /*
1517                  * Don't care if we're bound or not (due to netdev problems)
1518                  * can_rx_unregister() is always a save thing to do here.
1519                  */
1520                 if (op->ifindex) {
1521                         /*
1522                          * Only remove subscriptions that had not
1523                          * been removed due to NETDEV_UNREGISTER
1524                          * in bcm_notifier()
1525                          */
1526                         if (op->rx_reg_dev) {
1527                                 struct net_device *dev;
1528 
1529                                 dev = dev_get_by_index(net, op->ifindex);
1530                                 if (dev) {
1531                                         bcm_rx_unreg(dev, op);
1532                                         dev_put(dev);
1533                                 }
1534                         }
1535                 } else
1536                         can_rx_unregister(net, NULL, op->can_id,
1537                                           REGMASK(op->can_id),
1538                                           bcm_rx_handler, op);
1539 
1540                 bcm_remove_op(op);
1541         }
1542 
1543 #if IS_ENABLED(CONFIG_PROC_FS)
1544         /* remove procfs entry */
1545         if (net->can.bcmproc_dir && bo->bcm_proc_read)
1546                 remove_proc_entry(bo->procname, net->can.bcmproc_dir);
1547 #endif /* CONFIG_PROC_FS */
1548 
1549         /* remove device reference */
1550         if (bo->bound) {
1551                 bo->bound   = 0;
1552                 bo->ifindex = 0;
1553         }
1554 
1555         sock_orphan(sk);
1556         sock->sk = NULL;
1557 
1558         release_sock(sk);
1559         sock_put(sk);
1560 
1561         return 0;
1562 }
1563 
1564 static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
1565                        int flags)
1566 {
1567         struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
1568         struct sock *sk = sock->sk;
1569         struct bcm_sock *bo = bcm_sk(sk);
1570         struct net *net = sock_net(sk);
1571         int ret = 0;
1572 
1573         if (len < sizeof(*addr))
1574                 return -EINVAL;
1575 
1576         lock_sock(sk);
1577 
1578         if (bo->bound) {
1579                 ret = -EISCONN;
1580                 goto fail;
1581         }
1582 
1583         /* bind a device to this socket */
1584         if (addr->can_ifindex) {
1585                 struct net_device *dev;
1586 
1587                 dev = dev_get_by_index(net, addr->can_ifindex);
1588                 if (!dev) {
1589                         ret = -ENODEV;
1590                         goto fail;
1591                 }
1592                 if (dev->type != ARPHRD_CAN) {
1593                         dev_put(dev);
1594                         ret = -ENODEV;
1595                         goto fail;
1596                 }
1597 
1598                 bo->ifindex = dev->ifindex;
1599                 dev_put(dev);
1600 
1601         } else {
1602                 /* no interface reference for ifindex = 0 ('any' CAN device) */
1603                 bo->ifindex = 0;
1604         }
1605 
1606 #if IS_ENABLED(CONFIG_PROC_FS)
1607         if (net->can.bcmproc_dir) {
1608                 /* unique socket address as filename */
1609                 sprintf(bo->procname, "%lu", sock_i_ino(sk));
1610                 bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
1611                                                      net->can.bcmproc_dir,
1612                                                      &bcm_proc_fops, sk);
1613                 if (!bo->bcm_proc_read) {
1614                         ret = -ENOMEM;
1615                         goto fail;
1616                 }
1617         }
1618 #endif /* CONFIG_PROC_FS */
1619 
1620         bo->bound = 1;
1621 
1622 fail:
1623         release_sock(sk);
1624 
1625         return ret;
1626 }
1627 
1628 static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1629                        int flags)
1630 {
1631         struct sock *sk = sock->sk;
1632         struct sk_buff *skb;
1633         int error = 0;
1634         int noblock;
1635         int err;
1636 
1637         noblock =  flags & MSG_DONTWAIT;
1638         flags   &= ~MSG_DONTWAIT;
1639         skb = skb_recv_datagram(sk, flags, noblock, &error);
1640         if (!skb)
1641                 return error;
1642 
1643         if (skb->len < size)
1644                 size = skb->len;
1645 
1646         err = memcpy_to_msg(msg, skb->data, size);
1647         if (err < 0) {
1648                 skb_free_datagram(sk, skb);
1649                 return err;
1650         }
1651 
1652         sock_recv_ts_and_drops(msg, sk, skb);
1653 
1654         if (msg->msg_name) {
1655                 __sockaddr_check_size(sizeof(struct sockaddr_can));
1656                 msg->msg_namelen = sizeof(struct sockaddr_can);
1657                 memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
1658         }
1659 
1660         skb_free_datagram(sk, skb);
1661 
1662         return size;
1663 }
1664 
1665 static const struct proto_ops bcm_ops = {
1666         .family        = PF_CAN,
1667         .release       = bcm_release,
1668         .bind          = sock_no_bind,
1669         .connect       = bcm_connect,
1670         .socketpair    = sock_no_socketpair,
1671         .accept        = sock_no_accept,
1672         .getname       = sock_no_getname,
1673         .poll          = datagram_poll,
1674         .ioctl         = can_ioctl,     /* use can_ioctl() from af_can.c */
1675         .listen        = sock_no_listen,
1676         .shutdown      = sock_no_shutdown,
1677         .setsockopt    = sock_no_setsockopt,
1678         .getsockopt    = sock_no_getsockopt,
1679         .sendmsg       = bcm_sendmsg,
1680         .recvmsg       = bcm_recvmsg,
1681         .mmap          = sock_no_mmap,
1682         .sendpage      = sock_no_sendpage,
1683 };
1684 
1685 static struct proto bcm_proto __read_mostly = {
1686         .name       = "CAN_BCM",
1687         .owner      = THIS_MODULE,
1688         .obj_size   = sizeof(struct bcm_sock),
1689         .init       = bcm_init,
1690 };
1691 
1692 static const struct can_proto bcm_can_proto = {
1693         .type       = SOCK_DGRAM,
1694         .protocol   = CAN_BCM,
1695         .ops        = &bcm_ops,
1696         .prot       = &bcm_proto,
1697 };
1698 
1699 static int canbcm_pernet_init(struct net *net)
1700 {
1701 #if IS_ENABLED(CONFIG_PROC_FS)
1702         /* create /proc/net/can-bcm directory */
1703         net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
1704 #endif /* CONFIG_PROC_FS */
1705 
1706         return 0;
1707 }
1708 
1709 static void canbcm_pernet_exit(struct net *net)
1710 {
1711 #if IS_ENABLED(CONFIG_PROC_FS)
1712         /* remove /proc/net/can-bcm directory */
1713         if (net->can.bcmproc_dir)
1714                 remove_proc_entry("can-bcm", net->proc_net);
1715 #endif /* CONFIG_PROC_FS */
1716 }
1717 
1718 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
1719         .init = canbcm_pernet_init,
1720         .exit = canbcm_pernet_exit,
1721 };
1722 
1723 static int __init bcm_module_init(void)
1724 {
1725         int err;
1726 
1727         pr_info("can: broadcast manager protocol (rev " CAN_BCM_VERSION " t)\n");
1728 
1729         err = can_proto_register(&bcm_can_proto);
1730         if (err < 0) {
1731                 printk(KERN_ERR "can: registration of bcm protocol failed\n");
1732                 return err;
1733         }
1734 
1735         register_pernet_subsys(&canbcm_pernet_ops);
1736         return 0;
1737 }
1738 
1739 static void __exit bcm_module_exit(void)
1740 {
1741         can_proto_unregister(&bcm_can_proto);
1742         unregister_pernet_subsys(&canbcm_pernet_ops);
1743 }
1744 
1745 module_init(bcm_module_init);
1746 module_exit(bcm_module_exit);
1747 

~ [ 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