1 /*
2 * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
3 * Copyright (C) 2006 Andrey Volkov, Varma Electronics
4 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the version 2 of the GNU General Public License
8 * as published by the Free Software Foundation
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/slab.h>
23 #include <linux/netdevice.h>
24 #include <linux/if_arp.h>
25 #include <linux/can.h>
26 #include <linux/can/dev.h>
27 #include <linux/can/netlink.h>
28 #include <net/rtnetlink.h>
29
30 #define MOD_DESC "CAN device driver interface"
31
32 MODULE_DESCRIPTION(MOD_DESC);
33 MODULE_LICENSE("GPL v2");
34 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
35
36 #ifdef CONFIG_CAN_CALC_BITTIMING
37 #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
38
39 /*
40 * Bit-timing calculation derived from:
41 *
42 * Code based on LinCAN sources and H8S2638 project
43 * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
44 * Copyright 2005 Stanislav Marek
45 * email: pisa@cmp.felk.cvut.cz
46 *
47 * Calculates proper bit-timing parameters for a specified bit-rate
48 * and sample-point, which can then be used to set the bit-timing
49 * registers of the CAN controller. You can find more information
50 * in the header file linux/can/netlink.h.
51 */
can_update_spt(const struct can_bittiming_const * btc,int sampl_pt,int tseg,int * tseg1,int * tseg2)52 static int can_update_spt(const struct can_bittiming_const *btc,
53 int sampl_pt, int tseg, int *tseg1, int *tseg2)
54 {
55 *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000;
56 if (*tseg2 < btc->tseg2_min)
57 *tseg2 = btc->tseg2_min;
58 if (*tseg2 > btc->tseg2_max)
59 *tseg2 = btc->tseg2_max;
60 *tseg1 = tseg - *tseg2;
61 if (*tseg1 > btc->tseg1_max) {
62 *tseg1 = btc->tseg1_max;
63 *tseg2 = tseg - *tseg1;
64 }
65 return 1000 * (tseg + 1 - *tseg2) / (tseg + 1);
66 }
67
can_calc_bittiming(struct net_device * dev,struct can_bittiming * bt)68 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
69 {
70 struct can_priv *priv = netdev_priv(dev);
71 const struct can_bittiming_const *btc = priv->bittiming_const;
72 long rate, best_rate = 0;
73 long best_error = 1000000000, error = 0;
74 int best_tseg = 0, best_brp = 0, brp = 0;
75 int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0;
76 int spt_error = 1000, spt = 0, sampl_pt;
77 u64 v64;
78
79 if (!priv->bittiming_const)
80 return -ENOTSUPP;
81
82 /* Use CIA recommended sample points */
83 if (bt->sample_point) {
84 sampl_pt = bt->sample_point;
85 } else {
86 if (bt->bitrate > 800000)
87 sampl_pt = 750;
88 else if (bt->bitrate > 500000)
89 sampl_pt = 800;
90 else
91 sampl_pt = 875;
92 }
93
94 /* tseg even = round down, odd = round up */
95 for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
96 tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
97 tsegall = 1 + tseg / 2;
98 /* Compute all possible tseg choices (tseg=tseg1+tseg2) */
99 brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
100 /* chose brp step which is possible in system */
101 brp = (brp / btc->brp_inc) * btc->brp_inc;
102 if ((brp < btc->brp_min) || (brp > btc->brp_max))
103 continue;
104 rate = priv->clock.freq / (brp * tsegall);
105 error = bt->bitrate - rate;
106 /* tseg brp biterror */
107 if (error < 0)
108 error = -error;
109 if (error > best_error)
110 continue;
111 best_error = error;
112 if (error == 0) {
113 spt = can_update_spt(btc, sampl_pt, tseg / 2,
114 &tseg1, &tseg2);
115 error = sampl_pt - spt;
116 if (error < 0)
117 error = -error;
118 if (error > spt_error)
119 continue;
120 spt_error = error;
121 }
122 best_tseg = tseg / 2;
123 best_brp = brp;
124 best_rate = rate;
125 if (error == 0)
126 break;
127 }
128
129 if (best_error) {
130 /* Error in one-tenth of a percent */
131 error = (best_error * 1000) / bt->bitrate;
132 if (error > CAN_CALC_MAX_ERROR) {
133 netdev_err(dev,
134 "bitrate error %ld.%ld%% too high\n",
135 error / 10, error % 10);
136 return -EDOM;
137 } else {
138 netdev_warn(dev, "bitrate error %ld.%ld%%\n",
139 error / 10, error % 10);
140 }
141 }
142
143 /* real sample point */
144 bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg,
145 &tseg1, &tseg2);
146
147 v64 = (u64)best_brp * 1000000000UL;
148 do_div(v64, priv->clock.freq);
149 bt->tq = (u32)v64;
150 bt->prop_seg = tseg1 / 2;
151 bt->phase_seg1 = tseg1 - bt->prop_seg;
152 bt->phase_seg2 = tseg2;
153
154 /* check for sjw user settings */
155 if (!bt->sjw || !btc->sjw_max)
156 bt->sjw = 1;
157 else {
158 /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
159 if (bt->sjw > btc->sjw_max)
160 bt->sjw = btc->sjw_max;
161 /* bt->sjw must not be higher than tseg2 */
162 if (tseg2 < bt->sjw)
163 bt->sjw = tseg2;
164 }
165
166 bt->brp = best_brp;
167 /* real bit-rate */
168 bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1));
169
170 return 0;
171 }
172 #else /* !CONFIG_CAN_CALC_BITTIMING */
can_calc_bittiming(struct net_device * dev,struct can_bittiming * bt)173 static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt)
174 {
175 netdev_err(dev, "bit-timing calculation not available\n");
176 return -EINVAL;
177 }
178 #endif /* CONFIG_CAN_CALC_BITTIMING */
179
180 /*
181 * Checks the validity of the specified bit-timing parameters prop_seg,
182 * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
183 * prescaler value brp. You can find more information in the header
184 * file linux/can/netlink.h.
185 */
can_fixup_bittiming(struct net_device * dev,struct can_bittiming * bt)186 static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt)
187 {
188 struct can_priv *priv = netdev_priv(dev);
189 const struct can_bittiming_const *btc = priv->bittiming_const;
190 int tseg1, alltseg;
191 u64 brp64;
192
193 if (!priv->bittiming_const)
194 return -ENOTSUPP;
195
196 tseg1 = bt->prop_seg + bt->phase_seg1;
197 if (!bt->sjw)
198 bt->sjw = 1;
199 if (bt->sjw > btc->sjw_max ||
200 tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
201 bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
202 return -ERANGE;
203
204 brp64 = (u64)priv->clock.freq * (u64)bt->tq;
205 if (btc->brp_inc > 1)
206 do_div(brp64, btc->brp_inc);
207 brp64 += 500000000UL - 1;
208 do_div(brp64, 1000000000UL); /* the practicable BRP */
209 if (btc->brp_inc > 1)
210 brp64 *= btc->brp_inc;
211 bt->brp = (u32)brp64;
212
213 if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
214 return -EINVAL;
215
216 alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
217 bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
218 bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
219
220 return 0;
221 }
222
can_get_bittiming(struct net_device * dev,struct can_bittiming * bt)223 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt)
224 {
225 struct can_priv *priv = netdev_priv(dev);
226 int err;
227
228 /* Check if the CAN device has bit-timing parameters */
229 if (priv->bittiming_const) {
230
231 /* Non-expert mode? Check if the bitrate has been pre-defined */
232 if (!bt->tq)
233 /* Determine bit-timing parameters */
234 err = can_calc_bittiming(dev, bt);
235 else
236 /* Check bit-timing params and calculate proper brp */
237 err = can_fixup_bittiming(dev, bt);
238 if (err)
239 return err;
240 }
241
242 return 0;
243 }
244
245 /*
246 * Local echo of CAN messages
247 *
248 * CAN network devices *should* support a local echo functionality
249 * (see Documentation/networking/can.txt). To test the handling of CAN
250 * interfaces that do not support the local echo both driver types are
251 * implemented. In the case that the driver does not support the echo
252 * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
253 * to perform the echo as a fallback solution.
254 */
can_flush_echo_skb(struct net_device * dev)255 static void can_flush_echo_skb(struct net_device *dev)
256 {
257 struct can_priv *priv = netdev_priv(dev);
258 struct net_device_stats *stats = &dev->stats;
259 int i;
260
261 for (i = 0; i < priv->echo_skb_max; i++) {
262 if (priv->echo_skb[i]) {
263 kfree_skb(priv->echo_skb[i]);
264 priv->echo_skb[i] = NULL;
265 stats->tx_dropped++;
266 stats->tx_aborted_errors++;
267 }
268 }
269 }
270
271 /*
272 * Put the skb on the stack to be looped backed locally lateron
273 *
274 * The function is typically called in the start_xmit function
275 * of the device driver. The driver must protect access to
276 * priv->echo_skb, if necessary.
277 */
can_put_echo_skb(struct sk_buff * skb,struct net_device * dev,unsigned int idx)278 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
279 unsigned int idx)
280 {
281 struct can_priv *priv = netdev_priv(dev);
282
283 BUG_ON(idx >= priv->echo_skb_max);
284
285 /* check flag whether this packet has to be looped back */
286 if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) {
287 kfree_skb(skb);
288 return;
289 }
290
291 if (!priv->echo_skb[idx]) {
292 struct sock *srcsk = skb->sk;
293
294 if (atomic_read(&skb->users) != 1) {
295 struct sk_buff *old_skb = skb;
296
297 skb = skb_clone(old_skb, GFP_ATOMIC);
298 kfree_skb(old_skb);
299 if (!skb)
300 return;
301 } else
302 skb_orphan(skb);
303
304 skb->sk = srcsk;
305
306 /* make settings for echo to reduce code in irq context */
307 skb->protocol = htons(ETH_P_CAN);
308 skb->pkt_type = PACKET_BROADCAST;
309 skb->ip_summed = CHECKSUM_UNNECESSARY;
310 skb->dev = dev;
311
312 /* save this skb for tx interrupt echo handling */
313 priv->echo_skb[idx] = skb;
314 } else {
315 /* locking problem with netif_stop_queue() ?? */
316 netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
317 kfree_skb(skb);
318 }
319 }
320 EXPORT_SYMBOL_GPL(can_put_echo_skb);
321
322 /*
323 * Get the skb from the stack and loop it back locally
324 *
325 * The function is typically called when the TX done interrupt
326 * is handled in the device driver. The driver must protect
327 * access to priv->echo_skb, if necessary.
328 */
can_get_echo_skb(struct net_device * dev,unsigned int idx)329 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
330 {
331 struct can_priv *priv = netdev_priv(dev);
332
333 BUG_ON(idx >= priv->echo_skb_max);
334
335 if (priv->echo_skb[idx]) {
336 struct sk_buff *skb = priv->echo_skb[idx];
337 struct can_frame *cf = (struct can_frame *)skb->data;
338 u8 dlc = cf->can_dlc;
339
340 netif_rx(priv->echo_skb[idx]);
341 priv->echo_skb[idx] = NULL;
342
343 return dlc;
344 }
345
346 return 0;
347 }
348 EXPORT_SYMBOL_GPL(can_get_echo_skb);
349
350 /*
351 * Remove the skb from the stack and free it.
352 *
353 * The function is typically called when TX failed.
354 */
can_free_echo_skb(struct net_device * dev,unsigned int idx)355 void can_free_echo_skb(struct net_device *dev, unsigned int idx)
356 {
357 struct can_priv *priv = netdev_priv(dev);
358
359 BUG_ON(idx >= priv->echo_skb_max);
360
361 if (priv->echo_skb[idx]) {
362 kfree_skb(priv->echo_skb[idx]);
363 priv->echo_skb[idx] = NULL;
364 }
365 }
366 EXPORT_SYMBOL_GPL(can_free_echo_skb);
367
368 /*
369 * CAN device restart for bus-off recovery
370 */
can_restart(unsigned long data)371 void can_restart(unsigned long data)
372 {
373 struct net_device *dev = (struct net_device *)data;
374 struct can_priv *priv = netdev_priv(dev);
375 struct net_device_stats *stats = &dev->stats;
376 struct sk_buff *skb;
377 struct can_frame *cf;
378 int err;
379
380 BUG_ON(netif_carrier_ok(dev));
381
382 /*
383 * No synchronization needed because the device is bus-off and
384 * no messages can come in or go out.
385 */
386 can_flush_echo_skb(dev);
387
388 /* send restart message upstream */
389 skb = alloc_can_err_skb(dev, &cf);
390 if (skb == NULL) {
391 err = -ENOMEM;
392 goto restart;
393 }
394 cf->can_id |= CAN_ERR_RESTARTED;
395
396 netif_rx(skb);
397
398 stats->rx_packets++;
399 stats->rx_bytes += cf->can_dlc;
400
401 restart:
402 netdev_dbg(dev, "restarted\n");
403 priv->can_stats.restarts++;
404
405 /* Now restart the device */
406 err = priv->do_set_mode(dev, CAN_MODE_START);
407
408 netif_carrier_on(dev);
409 if (err)
410 netdev_err(dev, "Error %d during restart", err);
411 }
412
can_restart_now(struct net_device * dev)413 int can_restart_now(struct net_device *dev)
414 {
415 struct can_priv *priv = netdev_priv(dev);
416
417 /*
418 * A manual restart is only permitted if automatic restart is
419 * disabled and the device is in the bus-off state
420 */
421 if (priv->restart_ms)
422 return -EINVAL;
423 if (priv->state != CAN_STATE_BUS_OFF)
424 return -EBUSY;
425
426 /* Runs as soon as possible in the timer context */
427 mod_timer(&priv->restart_timer, jiffies);
428
429 return 0;
430 }
431
432 /*
433 * CAN bus-off
434 *
435 * This functions should be called when the device goes bus-off to
436 * tell the netif layer that no more packets can be sent or received.
437 * If enabled, a timer is started to trigger bus-off recovery.
438 */
can_bus_off(struct net_device * dev)439 void can_bus_off(struct net_device *dev)
440 {
441 struct can_priv *priv = netdev_priv(dev);
442
443 netdev_dbg(dev, "bus-off\n");
444
445 netif_carrier_off(dev);
446 priv->can_stats.bus_off++;
447
448 if (priv->restart_ms)
449 mod_timer(&priv->restart_timer,
450 jiffies + (priv->restart_ms * HZ) / 1000);
451 }
452 EXPORT_SYMBOL_GPL(can_bus_off);
453
can_setup(struct net_device * dev)454 static void can_setup(struct net_device *dev)
455 {
456 dev->type = ARPHRD_CAN;
457 dev->mtu = sizeof(struct can_frame);
458 dev->hard_header_len = 0;
459 dev->addr_len = 0;
460 dev->tx_queue_len = 10;
461
462 /* New-style flags. */
463 dev->flags = IFF_NOARP;
464 dev->features = NETIF_F_HW_CSUM;
465 }
466
alloc_can_skb(struct net_device * dev,struct can_frame ** cf)467 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
468 {
469 struct sk_buff *skb;
470
471 skb = netdev_alloc_skb(dev, sizeof(struct can_frame));
472 if (unlikely(!skb))
473 return NULL;
474
475 skb->protocol = htons(ETH_P_CAN);
476 skb->pkt_type = PACKET_BROADCAST;
477 skb->ip_summed = CHECKSUM_UNNECESSARY;
478 *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
479 memset(*cf, 0, sizeof(struct can_frame));
480
481 return skb;
482 }
483 EXPORT_SYMBOL_GPL(alloc_can_skb);
484
alloc_can_err_skb(struct net_device * dev,struct can_frame ** cf)485 struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
486 {
487 struct sk_buff *skb;
488
489 skb = alloc_can_skb(dev, cf);
490 if (unlikely(!skb))
491 return NULL;
492
493 (*cf)->can_id = CAN_ERR_FLAG;
494 (*cf)->can_dlc = CAN_ERR_DLC;
495
496 return skb;
497 }
498 EXPORT_SYMBOL_GPL(alloc_can_err_skb);
499
500 /*
501 * Allocate and setup space for the CAN network device
502 */
alloc_candev(int sizeof_priv,unsigned int echo_skb_max)503 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
504 {
505 struct net_device *dev;
506 struct can_priv *priv;
507 int size;
508
509 if (echo_skb_max)
510 size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
511 echo_skb_max * sizeof(struct sk_buff *);
512 else
513 size = sizeof_priv;
514
515 dev = alloc_netdev(size, "can%d", can_setup);
516 if (!dev)
517 return NULL;
518
519 priv = netdev_priv(dev);
520
521 if (echo_skb_max) {
522 priv->echo_skb_max = echo_skb_max;
523 priv->echo_skb = (void *)priv +
524 ALIGN(sizeof_priv, sizeof(struct sk_buff *));
525 }
526
527 priv->state = CAN_STATE_STOPPED;
528
529 init_timer(&priv->restart_timer);
530
531 return dev;
532 }
533 EXPORT_SYMBOL_GPL(alloc_candev);
534
535 /*
536 * Free space of the CAN network device
537 */
free_candev(struct net_device * dev)538 void free_candev(struct net_device *dev)
539 {
540 free_netdev(dev);
541 }
542 EXPORT_SYMBOL_GPL(free_candev);
543
544 /*
545 * Common open function when the device gets opened.
546 *
547 * This function should be called in the open function of the device
548 * driver.
549 */
open_candev(struct net_device * dev)550 int open_candev(struct net_device *dev)
551 {
552 struct can_priv *priv = netdev_priv(dev);
553
554 if (!priv->bittiming.tq && !priv->bittiming.bitrate) {
555 netdev_err(dev, "bit-timing not yet defined\n");
556 return -EINVAL;
557 }
558
559 /* Switch carrier on if device was stopped while in bus-off state */
560 if (!netif_carrier_ok(dev))
561 netif_carrier_on(dev);
562
563 setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
564
565 return 0;
566 }
567 EXPORT_SYMBOL_GPL(open_candev);
568
569 /*
570 * Common close function for cleanup before the device gets closed.
571 *
572 * This function should be called in the close function of the device
573 * driver.
574 */
close_candev(struct net_device * dev)575 void close_candev(struct net_device *dev)
576 {
577 struct can_priv *priv = netdev_priv(dev);
578
579 del_timer_sync(&priv->restart_timer);
580 can_flush_echo_skb(dev);
581 }
582 EXPORT_SYMBOL_GPL(close_candev);
583
584 /*
585 * CAN netlink interface
586 */
587 static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
588 [IFLA_CAN_STATE] = { .type = NLA_U32 },
589 [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
590 [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
591 [IFLA_CAN_RESTART] = { .type = NLA_U32 },
592 [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
593 [IFLA_CAN_BITTIMING_CONST]
594 = { .len = sizeof(struct can_bittiming_const) },
595 [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
596 [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
597 };
598
can_changelink(struct net_device * dev,struct nlattr * tb[],struct nlattr * data[])599 static int can_changelink(struct net_device *dev,
600 struct nlattr *tb[], struct nlattr *data[])
601 {
602 struct can_priv *priv = netdev_priv(dev);
603 int err;
604
605 /* We need synchronization with dev->stop() */
606 ASSERT_RTNL();
607
608 if (data[IFLA_CAN_CTRLMODE]) {
609 struct can_ctrlmode *cm;
610
611 /* Do not allow changing controller mode while running */
612 if (dev->flags & IFF_UP)
613 return -EBUSY;
614 cm = nla_data(data[IFLA_CAN_CTRLMODE]);
615 if (cm->flags & ~priv->ctrlmode_supported)
616 return -EOPNOTSUPP;
617 priv->ctrlmode &= ~cm->mask;
618 priv->ctrlmode |= cm->flags;
619 }
620
621 if (data[IFLA_CAN_BITTIMING]) {
622 struct can_bittiming bt;
623
624 /* Do not allow changing bittiming while running */
625 if (dev->flags & IFF_UP)
626 return -EBUSY;
627 memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
628 if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq))
629 return -EINVAL;
630 err = can_get_bittiming(dev, &bt);
631 if (err)
632 return err;
633 memcpy(&priv->bittiming, &bt, sizeof(bt));
634
635 if (priv->do_set_bittiming) {
636 /* Finally, set the bit-timing registers */
637 err = priv->do_set_bittiming(dev);
638 if (err)
639 return err;
640 }
641 }
642
643 if (data[IFLA_CAN_RESTART_MS]) {
644 /* Do not allow changing restart delay while running */
645 if (dev->flags & IFF_UP)
646 return -EBUSY;
647 priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
648 }
649
650 if (data[IFLA_CAN_RESTART]) {
651 /* Do not allow a restart while not running */
652 if (!(dev->flags & IFF_UP))
653 return -EINVAL;
654 err = can_restart_now(dev);
655 if (err)
656 return err;
657 }
658
659 return 0;
660 }
661
can_get_size(const struct net_device * dev)662 static size_t can_get_size(const struct net_device *dev)
663 {
664 struct can_priv *priv = netdev_priv(dev);
665 size_t size;
666
667 size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
668 size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
669 size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
670 size += nla_total_size(sizeof(struct can_bittiming)); /* IFLA_CAN_BITTIMING */
671 size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
672 if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
673 size += nla_total_size(sizeof(struct can_berr_counter));
674 if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
675 size += nla_total_size(sizeof(struct can_bittiming_const));
676
677 return size;
678 }
679
can_fill_info(struct sk_buff * skb,const struct net_device * dev)680 static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
681 {
682 struct can_priv *priv = netdev_priv(dev);
683 struct can_ctrlmode cm = {.flags = priv->ctrlmode};
684 struct can_berr_counter bec;
685 enum can_state state = priv->state;
686
687 if (priv->do_get_state)
688 priv->do_get_state(dev, &state);
689 NLA_PUT_U32(skb, IFLA_CAN_STATE, state);
690 NLA_PUT(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm);
691 NLA_PUT_U32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms);
692 NLA_PUT(skb, IFLA_CAN_BITTIMING,
693 sizeof(priv->bittiming), &priv->bittiming);
694 NLA_PUT(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock);
695 if (priv->do_get_berr_counter && !priv->do_get_berr_counter(dev, &bec))
696 NLA_PUT(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec);
697 if (priv->bittiming_const)
698 NLA_PUT(skb, IFLA_CAN_BITTIMING_CONST,
699 sizeof(*priv->bittiming_const), priv->bittiming_const);
700
701 return 0;
702
703 nla_put_failure:
704 return -EMSGSIZE;
705 }
706
can_get_xstats_size(const struct net_device * dev)707 static size_t can_get_xstats_size(const struct net_device *dev)
708 {
709 return sizeof(struct can_device_stats);
710 }
711
can_fill_xstats(struct sk_buff * skb,const struct net_device * dev)712 static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
713 {
714 struct can_priv *priv = netdev_priv(dev);
715
716 NLA_PUT(skb, IFLA_INFO_XSTATS,
717 sizeof(priv->can_stats), &priv->can_stats);
718
719 return 0;
720
721 nla_put_failure:
722 return -EMSGSIZE;
723 }
724
can_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[])725 static int can_newlink(struct net *src_net, struct net_device *dev,
726 struct nlattr *tb[], struct nlattr *data[])
727 {
728 return -EOPNOTSUPP;
729 }
730
731 static struct rtnl_link_ops can_link_ops __read_mostly = {
732 .kind = "can",
733 .maxtype = IFLA_CAN_MAX,
734 .policy = can_policy,
735 .setup = can_setup,
736 .newlink = can_newlink,
737 .changelink = can_changelink,
738 .get_size = can_get_size,
739 .fill_info = can_fill_info,
740 .get_xstats_size = can_get_xstats_size,
741 .fill_xstats = can_fill_xstats,
742 };
743
744 /*
745 * Register the CAN network device
746 */
register_candev(struct net_device * dev)747 int register_candev(struct net_device *dev)
748 {
749 dev->rtnl_link_ops = &can_link_ops;
750 return register_netdev(dev);
751 }
752 EXPORT_SYMBOL_GPL(register_candev);
753
754 /*
755 * Unregister the CAN network device
756 */
unregister_candev(struct net_device * dev)757 void unregister_candev(struct net_device *dev)
758 {
759 unregister_netdev(dev);
760 }
761 EXPORT_SYMBOL_GPL(unregister_candev);
762
can_dev_init(void)763 static __init int can_dev_init(void)
764 {
765 int err;
766
767 err = rtnl_link_register(&can_link_ops);
768 if (!err)
769 printk(KERN_INFO MOD_DESC "\n");
770
771 return err;
772 }
773 module_init(can_dev_init);
774
can_dev_exit(void)775 static __exit void can_dev_exit(void)
776 {
777 rtnl_link_unregister(&can_link_ops);
778 }
779 module_exit(can_dev_exit);
780
781 MODULE_ALIAS_RTNL_LINK("can");
782