Root/
1 | /* |
2 | * af_can.c - Protocol family CAN core module |
3 | * (used by different CAN protocol modules) |
4 | * |
5 | * Copyright (c) 2002-2007 Volkswagen Group Electronic Research |
6 | * All rights reserved. |
7 | * |
8 | * Redistribution and use in source and binary forms, with or without |
9 | * modification, are permitted provided that the following conditions |
10 | * are met: |
11 | * 1. Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. |
13 | * 2. Redistributions in binary form must reproduce the above copyright |
14 | * notice, this list of conditions and the following disclaimer in the |
15 | * documentation and/or other materials provided with the distribution. |
16 | * 3. Neither the name of Volkswagen nor the names of its contributors |
17 | * may be used to endorse or promote products derived from this software |
18 | * without specific prior written permission. |
19 | * |
20 | * Alternatively, provided that this notice is retained in full, this |
21 | * software may be distributed under the terms of the GNU General |
22 | * Public License ("GPL") version 2, in which case the provisions of the |
23 | * GPL apply INSTEAD OF those given above. |
24 | * |
25 | * The provided data structures and external interfaces from this code |
26 | * are not restricted to be used by modules with a GPL compatible license. |
27 | * |
28 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
29 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
30 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
31 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
32 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
33 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
34 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
35 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
36 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
37 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
38 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
39 | * DAMAGE. |
40 | * |
41 | * Send feedback to <socketcan-users@lists.berlios.de> |
42 | * |
43 | */ |
44 | |
45 | #include <linux/module.h> |
46 | #include <linux/init.h> |
47 | #include <linux/kmod.h> |
48 | #include <linux/slab.h> |
49 | #include <linux/list.h> |
50 | #include <linux/spinlock.h> |
51 | #include <linux/rcupdate.h> |
52 | #include <linux/uaccess.h> |
53 | #include <linux/net.h> |
54 | #include <linux/netdevice.h> |
55 | #include <linux/socket.h> |
56 | #include <linux/if_ether.h> |
57 | #include <linux/if_arp.h> |
58 | #include <linux/skbuff.h> |
59 | #include <linux/can.h> |
60 | #include <linux/can/core.h> |
61 | #include <net/net_namespace.h> |
62 | #include <net/sock.h> |
63 | |
64 | #include "af_can.h" |
65 | |
66 | static __initdata const char banner[] = KERN_INFO |
67 | "can: controller area network core (" CAN_VERSION_STRING ")\n"; |
68 | |
69 | MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); |
70 | MODULE_LICENSE("Dual BSD/GPL"); |
71 | MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, " |
72 | "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); |
73 | |
74 | MODULE_ALIAS_NETPROTO(PF_CAN); |
75 | |
76 | static int stats_timer __read_mostly = 1; |
77 | module_param(stats_timer, int, S_IRUGO); |
78 | MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); |
79 | |
80 | /* receive filters subscribed for 'all' CAN devices */ |
81 | struct dev_rcv_lists can_rx_alldev_list; |
82 | static DEFINE_SPINLOCK(can_rcvlists_lock); |
83 | |
84 | static struct kmem_cache *rcv_cache __read_mostly; |
85 | |
86 | /* table of registered CAN protocols */ |
87 | static struct can_proto *proto_tab[CAN_NPROTO] __read_mostly; |
88 | static DEFINE_SPINLOCK(proto_tab_lock); |
89 | |
90 | struct timer_list can_stattimer; /* timer for statistics update */ |
91 | struct s_stats can_stats; /* packet statistics */ |
92 | struct s_pstats can_pstats; /* receive list statistics */ |
93 | |
94 | /* |
95 | * af_can socket functions |
96 | */ |
97 | |
98 | static int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
99 | { |
100 | struct sock *sk = sock->sk; |
101 | |
102 | switch (cmd) { |
103 | |
104 | case SIOCGSTAMP: |
105 | return sock_get_timestamp(sk, (struct timeval __user *)arg); |
106 | |
107 | default: |
108 | return -ENOIOCTLCMD; |
109 | } |
110 | } |
111 | |
112 | static void can_sock_destruct(struct sock *sk) |
113 | { |
114 | skb_queue_purge(&sk->sk_receive_queue); |
115 | } |
116 | |
117 | static int can_create(struct net *net, struct socket *sock, int protocol, |
118 | int kern) |
119 | { |
120 | struct sock *sk; |
121 | struct can_proto *cp; |
122 | int err = 0; |
123 | |
124 | sock->state = SS_UNCONNECTED; |
125 | |
126 | if (protocol < 0 || protocol >= CAN_NPROTO) |
127 | return -EINVAL; |
128 | |
129 | if (!net_eq(net, &init_net)) |
130 | return -EAFNOSUPPORT; |
131 | |
132 | #ifdef CONFIG_MODULES |
133 | /* try to load protocol module kernel is modular */ |
134 | if (!proto_tab[protocol]) { |
135 | err = request_module("can-proto-%d", protocol); |
136 | |
137 | /* |
138 | * In case of error we only print a message but don't |
139 | * return the error code immediately. Below we will |
140 | * return -EPROTONOSUPPORT |
141 | */ |
142 | if (err && printk_ratelimit()) |
143 | printk(KERN_ERR "can: request_module " |
144 | "(can-proto-%d) failed.\n", protocol); |
145 | } |
146 | #endif |
147 | |
148 | spin_lock(&proto_tab_lock); |
149 | cp = proto_tab[protocol]; |
150 | if (cp && !try_module_get(cp->prot->owner)) |
151 | cp = NULL; |
152 | spin_unlock(&proto_tab_lock); |
153 | |
154 | /* check for available protocol and correct usage */ |
155 | |
156 | if (!cp) |
157 | return -EPROTONOSUPPORT; |
158 | |
159 | if (cp->type != sock->type) { |
160 | err = -EPROTONOSUPPORT; |
161 | goto errout; |
162 | } |
163 | |
164 | sock->ops = cp->ops; |
165 | |
166 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot); |
167 | if (!sk) { |
168 | err = -ENOMEM; |
169 | goto errout; |
170 | } |
171 | |
172 | sock_init_data(sock, sk); |
173 | sk->sk_destruct = can_sock_destruct; |
174 | |
175 | if (sk->sk_prot->init) |
176 | err = sk->sk_prot->init(sk); |
177 | |
178 | if (err) { |
179 | /* release sk on errors */ |
180 | sock_orphan(sk); |
181 | sock_put(sk); |
182 | } |
183 | |
184 | errout: |
185 | module_put(cp->prot->owner); |
186 | return err; |
187 | } |
188 | |
189 | /* |
190 | * af_can tx path |
191 | */ |
192 | |
193 | /** |
194 | * can_send - transmit a CAN frame (optional with local loopback) |
195 | * @skb: pointer to socket buffer with CAN frame in data section |
196 | * @loop: loopback for listeners on local CAN sockets (recommended default!) |
197 | * |
198 | * Due to the loopback this routine must not be called from hardirq context. |
199 | * |
200 | * Return: |
201 | * 0 on success |
202 | * -ENETDOWN when the selected interface is down |
203 | * -ENOBUFS on full driver queue (see net_xmit_errno()) |
204 | * -ENOMEM when local loopback failed at calling skb_clone() |
205 | * -EPERM when trying to send on a non-CAN interface |
206 | * -EINVAL when the skb->data does not contain a valid CAN frame |
207 | */ |
208 | int can_send(struct sk_buff *skb, int loop) |
209 | { |
210 | struct sk_buff *newskb = NULL; |
211 | struct can_frame *cf = (struct can_frame *)skb->data; |
212 | int err; |
213 | |
214 | if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) { |
215 | kfree_skb(skb); |
216 | return -EINVAL; |
217 | } |
218 | |
219 | if (skb->dev->type != ARPHRD_CAN) { |
220 | kfree_skb(skb); |
221 | return -EPERM; |
222 | } |
223 | |
224 | if (!(skb->dev->flags & IFF_UP)) { |
225 | kfree_skb(skb); |
226 | return -ENETDOWN; |
227 | } |
228 | |
229 | skb->protocol = htons(ETH_P_CAN); |
230 | skb_reset_network_header(skb); |
231 | skb_reset_transport_header(skb); |
232 | |
233 | if (loop) { |
234 | /* local loopback of sent CAN frames */ |
235 | |
236 | /* indication for the CAN driver: do loopback */ |
237 | skb->pkt_type = PACKET_LOOPBACK; |
238 | |
239 | /* |
240 | * The reference to the originating sock may be required |
241 | * by the receiving socket to check whether the frame is |
242 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS |
243 | * Therefore we have to ensure that skb->sk remains the |
244 | * reference to the originating sock by restoring skb->sk |
245 | * after each skb_clone() or skb_orphan() usage. |
246 | */ |
247 | |
248 | if (!(skb->dev->flags & IFF_ECHO)) { |
249 | /* |
250 | * If the interface is not capable to do loopback |
251 | * itself, we do it here. |
252 | */ |
253 | newskb = skb_clone(skb, GFP_ATOMIC); |
254 | if (!newskb) { |
255 | kfree_skb(skb); |
256 | return -ENOMEM; |
257 | } |
258 | |
259 | newskb->sk = skb->sk; |
260 | newskb->ip_summed = CHECKSUM_UNNECESSARY; |
261 | newskb->pkt_type = PACKET_BROADCAST; |
262 | } |
263 | } else { |
264 | /* indication for the CAN driver: no loopback required */ |
265 | skb->pkt_type = PACKET_HOST; |
266 | } |
267 | |
268 | /* send to netdevice */ |
269 | err = dev_queue_xmit(skb); |
270 | if (err > 0) |
271 | err = net_xmit_errno(err); |
272 | |
273 | if (err) { |
274 | kfree_skb(newskb); |
275 | return err; |
276 | } |
277 | |
278 | if (newskb) |
279 | netif_rx_ni(newskb); |
280 | |
281 | /* update statistics */ |
282 | can_stats.tx_frames++; |
283 | can_stats.tx_frames_delta++; |
284 | |
285 | return 0; |
286 | } |
287 | EXPORT_SYMBOL(can_send); |
288 | |
289 | /* |
290 | * af_can rx path |
291 | */ |
292 | |
293 | static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) |
294 | { |
295 | if (!dev) |
296 | return &can_rx_alldev_list; |
297 | else |
298 | return (struct dev_rcv_lists *)dev->ml_priv; |
299 | } |
300 | |
301 | /** |
302 | * find_rcv_list - determine optimal filterlist inside device filter struct |
303 | * @can_id: pointer to CAN identifier of a given can_filter |
304 | * @mask: pointer to CAN mask of a given can_filter |
305 | * @d: pointer to the device filter struct |
306 | * |
307 | * Description: |
308 | * Returns the optimal filterlist to reduce the filter handling in the |
309 | * receive path. This function is called by service functions that need |
310 | * to register or unregister a can_filter in the filter lists. |
311 | * |
312 | * A filter matches in general, when |
313 | * |
314 | * <received_can_id> & mask == can_id & mask |
315 | * |
316 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe |
317 | * relevant bits for the filter. |
318 | * |
319 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can |
320 | * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames |
321 | * there is a special filterlist and a special rx path filter handling. |
322 | * |
323 | * Return: |
324 | * Pointer to optimal filterlist for the given can_id/mask pair. |
325 | * Constistency checked mask. |
326 | * Reduced can_id to have a preprocessed filter compare value. |
327 | */ |
328 | static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, |
329 | struct dev_rcv_lists *d) |
330 | { |
331 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ |
332 | |
333 | /* filter for error frames in extra filterlist */ |
334 | if (*mask & CAN_ERR_FLAG) { |
335 | /* clear CAN_ERR_FLAG in filter entry */ |
336 | *mask &= CAN_ERR_MASK; |
337 | return &d->rx[RX_ERR]; |
338 | } |
339 | |
340 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
341 | |
342 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) |
343 | |
344 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ |
345 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) |
346 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); |
347 | |
348 | /* reduce condition testing at receive time */ |
349 | *can_id &= *mask; |
350 | |
351 | /* inverse can_id/can_mask filter */ |
352 | if (inv) |
353 | return &d->rx[RX_INV]; |
354 | |
355 | /* mask == 0 => no condition testing at receive time */ |
356 | if (!(*mask)) |
357 | return &d->rx[RX_ALL]; |
358 | |
359 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
360 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) && |
361 | !(*can_id & CAN_RTR_FLAG)) { |
362 | |
363 | if (*can_id & CAN_EFF_FLAG) { |
364 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) { |
365 | /* RFC: a future use-case for hash-tables? */ |
366 | return &d->rx[RX_EFF]; |
367 | } |
368 | } else { |
369 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) |
370 | return &d->rx_sff[*can_id]; |
371 | } |
372 | } |
373 | |
374 | /* default: filter via can_id/can_mask */ |
375 | return &d->rx[RX_FIL]; |
376 | } |
377 | |
378 | /** |
379 | * can_rx_register - subscribe CAN frames from a specific interface |
380 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) |
381 | * @can_id: CAN identifier (see description) |
382 | * @mask: CAN mask (see description) |
383 | * @func: callback function on filter match |
384 | * @data: returned parameter for callback function |
385 | * @ident: string for calling module indentification |
386 | * |
387 | * Description: |
388 | * Invokes the callback function with the received sk_buff and the given |
389 | * parameter 'data' on a matching receive filter. A filter matches, when |
390 | * |
391 | * <received_can_id> & mask == can_id & mask |
392 | * |
393 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can |
394 | * filter for error frames (CAN_ERR_FLAG bit set in mask). |
395 | * |
396 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
397 | * the callback function is running. The callback function must *not* free |
398 | * the given sk_buff while processing it's task. When the given sk_buff is |
399 | * needed after the end of the callback function it must be cloned inside |
400 | * the callback function with skb_clone(). |
401 | * |
402 | * Return: |
403 | * 0 on success |
404 | * -ENOMEM on missing cache mem to create subscription entry |
405 | * -ENODEV unknown device |
406 | */ |
407 | int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask, |
408 | void (*func)(struct sk_buff *, void *), void *data, |
409 | char *ident) |
410 | { |
411 | struct receiver *r; |
412 | struct hlist_head *rl; |
413 | struct dev_rcv_lists *d; |
414 | int err = 0; |
415 | |
416 | /* insert new receiver (dev,canid,mask) -> (func,data) */ |
417 | |
418 | if (dev && dev->type != ARPHRD_CAN) |
419 | return -ENODEV; |
420 | |
421 | r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); |
422 | if (!r) |
423 | return -ENOMEM; |
424 | |
425 | spin_lock(&can_rcvlists_lock); |
426 | |
427 | d = find_dev_rcv_lists(dev); |
428 | if (d) { |
429 | rl = find_rcv_list(&can_id, &mask, d); |
430 | |
431 | r->can_id = can_id; |
432 | r->mask = mask; |
433 | r->matches = 0; |
434 | r->func = func; |
435 | r->data = data; |
436 | r->ident = ident; |
437 | |
438 | hlist_add_head_rcu(&r->list, rl); |
439 | d->entries++; |
440 | |
441 | can_pstats.rcv_entries++; |
442 | if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) |
443 | can_pstats.rcv_entries_max = can_pstats.rcv_entries; |
444 | } else { |
445 | kmem_cache_free(rcv_cache, r); |
446 | err = -ENODEV; |
447 | } |
448 | |
449 | spin_unlock(&can_rcvlists_lock); |
450 | |
451 | return err; |
452 | } |
453 | EXPORT_SYMBOL(can_rx_register); |
454 | |
455 | /* |
456 | * can_rx_delete_receiver - rcu callback for single receiver entry removal |
457 | */ |
458 | static void can_rx_delete_receiver(struct rcu_head *rp) |
459 | { |
460 | struct receiver *r = container_of(rp, struct receiver, rcu); |
461 | |
462 | kmem_cache_free(rcv_cache, r); |
463 | } |
464 | |
465 | /** |
466 | * can_rx_unregister - unsubscribe CAN frames from a specific interface |
467 | * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list) |
468 | * @can_id: CAN identifier |
469 | * @mask: CAN mask |
470 | * @func: callback function on filter match |
471 | * @data: returned parameter for callback function |
472 | * |
473 | * Description: |
474 | * Removes subscription entry depending on given (subscription) values. |
475 | */ |
476 | void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, |
477 | void (*func)(struct sk_buff *, void *), void *data) |
478 | { |
479 | struct receiver *r = NULL; |
480 | struct hlist_head *rl; |
481 | struct hlist_node *next; |
482 | struct dev_rcv_lists *d; |
483 | |
484 | if (dev && dev->type != ARPHRD_CAN) |
485 | return; |
486 | |
487 | spin_lock(&can_rcvlists_lock); |
488 | |
489 | d = find_dev_rcv_lists(dev); |
490 | if (!d) { |
491 | printk(KERN_ERR "BUG: receive list not found for " |
492 | "dev %s, id %03X, mask %03X\n", |
493 | DNAME(dev), can_id, mask); |
494 | goto out; |
495 | } |
496 | |
497 | rl = find_rcv_list(&can_id, &mask, d); |
498 | |
499 | /* |
500 | * Search the receiver list for the item to delete. This should |
501 | * exist, since no receiver may be unregistered that hasn't |
502 | * been registered before. |
503 | */ |
504 | |
505 | hlist_for_each_entry_rcu(r, next, rl, list) { |
506 | if (r->can_id == can_id && r->mask == mask && |
507 | r->func == func && r->data == data) |
508 | break; |
509 | } |
510 | |
511 | /* |
512 | * Check for bugs in CAN protocol implementations: |
513 | * If no matching list item was found, the list cursor variable next |
514 | * will be NULL, while r will point to the last item of the list. |
515 | */ |
516 | |
517 | if (!next) { |
518 | printk(KERN_ERR "BUG: receive list entry not found for " |
519 | "dev %s, id %03X, mask %03X\n", |
520 | DNAME(dev), can_id, mask); |
521 | r = NULL; |
522 | goto out; |
523 | } |
524 | |
525 | hlist_del_rcu(&r->list); |
526 | d->entries--; |
527 | |
528 | if (can_pstats.rcv_entries > 0) |
529 | can_pstats.rcv_entries--; |
530 | |
531 | /* remove device structure requested by NETDEV_UNREGISTER */ |
532 | if (d->remove_on_zero_entries && !d->entries) { |
533 | kfree(d); |
534 | dev->ml_priv = NULL; |
535 | } |
536 | |
537 | out: |
538 | spin_unlock(&can_rcvlists_lock); |
539 | |
540 | /* schedule the receiver item for deletion */ |
541 | if (r) |
542 | call_rcu(&r->rcu, can_rx_delete_receiver); |
543 | } |
544 | EXPORT_SYMBOL(can_rx_unregister); |
545 | |
546 | static inline void deliver(struct sk_buff *skb, struct receiver *r) |
547 | { |
548 | r->func(skb, r->data); |
549 | r->matches++; |
550 | } |
551 | |
552 | static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) |
553 | { |
554 | struct receiver *r; |
555 | struct hlist_node *n; |
556 | int matches = 0; |
557 | struct can_frame *cf = (struct can_frame *)skb->data; |
558 | canid_t can_id = cf->can_id; |
559 | |
560 | if (d->entries == 0) |
561 | return 0; |
562 | |
563 | if (can_id & CAN_ERR_FLAG) { |
564 | /* check for error frame entries only */ |
565 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) { |
566 | if (can_id & r->mask) { |
567 | deliver(skb, r); |
568 | matches++; |
569 | } |
570 | } |
571 | return matches; |
572 | } |
573 | |
574 | /* check for unfiltered entries */ |
575 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) { |
576 | deliver(skb, r); |
577 | matches++; |
578 | } |
579 | |
580 | /* check for can_id/mask entries */ |
581 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) { |
582 | if ((can_id & r->mask) == r->can_id) { |
583 | deliver(skb, r); |
584 | matches++; |
585 | } |
586 | } |
587 | |
588 | /* check for inverted can_id/mask entries */ |
589 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) { |
590 | if ((can_id & r->mask) != r->can_id) { |
591 | deliver(skb, r); |
592 | matches++; |
593 | } |
594 | } |
595 | |
596 | /* check filterlists for single non-RTR can_ids */ |
597 | if (can_id & CAN_RTR_FLAG) |
598 | return matches; |
599 | |
600 | if (can_id & CAN_EFF_FLAG) { |
601 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) { |
602 | if (r->can_id == can_id) { |
603 | deliver(skb, r); |
604 | matches++; |
605 | } |
606 | } |
607 | } else { |
608 | can_id &= CAN_SFF_MASK; |
609 | hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) { |
610 | deliver(skb, r); |
611 | matches++; |
612 | } |
613 | } |
614 | |
615 | return matches; |
616 | } |
617 | |
618 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, |
619 | struct packet_type *pt, struct net_device *orig_dev) |
620 | { |
621 | struct dev_rcv_lists *d; |
622 | struct can_frame *cf = (struct can_frame *)skb->data; |
623 | int matches; |
624 | |
625 | if (!net_eq(dev_net(dev), &init_net)) |
626 | goto drop; |
627 | |
628 | if (WARN_ONCE(dev->type != ARPHRD_CAN || |
629 | skb->len != sizeof(struct can_frame) || |
630 | cf->can_dlc > 8, |
631 | "PF_CAN: dropped non conform skbuf: " |
632 | "dev type %d, len %d, can_dlc %d\n", |
633 | dev->type, skb->len, cf->can_dlc)) |
634 | goto drop; |
635 | |
636 | /* update statistics */ |
637 | can_stats.rx_frames++; |
638 | can_stats.rx_frames_delta++; |
639 | |
640 | rcu_read_lock(); |
641 | |
642 | /* deliver the packet to sockets listening on all devices */ |
643 | matches = can_rcv_filter(&can_rx_alldev_list, skb); |
644 | |
645 | /* find receive list for this device */ |
646 | d = find_dev_rcv_lists(dev); |
647 | if (d) |
648 | matches += can_rcv_filter(d, skb); |
649 | |
650 | rcu_read_unlock(); |
651 | |
652 | /* consume the skbuff allocated by the netdevice driver */ |
653 | consume_skb(skb); |
654 | |
655 | if (matches > 0) { |
656 | can_stats.matches++; |
657 | can_stats.matches_delta++; |
658 | } |
659 | |
660 | return NET_RX_SUCCESS; |
661 | |
662 | drop: |
663 | kfree_skb(skb); |
664 | return NET_RX_DROP; |
665 | } |
666 | |
667 | /* |
668 | * af_can protocol functions |
669 | */ |
670 | |
671 | /** |
672 | * can_proto_register - register CAN transport protocol |
673 | * @cp: pointer to CAN protocol structure |
674 | * |
675 | * Return: |
676 | * 0 on success |
677 | * -EINVAL invalid (out of range) protocol number |
678 | * -EBUSY protocol already in use |
679 | * -ENOBUF if proto_register() fails |
680 | */ |
681 | int can_proto_register(struct can_proto *cp) |
682 | { |
683 | int proto = cp->protocol; |
684 | int err = 0; |
685 | |
686 | if (proto < 0 || proto >= CAN_NPROTO) { |
687 | printk(KERN_ERR "can: protocol number %d out of range\n", |
688 | proto); |
689 | return -EINVAL; |
690 | } |
691 | |
692 | err = proto_register(cp->prot, 0); |
693 | if (err < 0) |
694 | return err; |
695 | |
696 | spin_lock(&proto_tab_lock); |
697 | if (proto_tab[proto]) { |
698 | printk(KERN_ERR "can: protocol %d already registered\n", |
699 | proto); |
700 | err = -EBUSY; |
701 | } else { |
702 | proto_tab[proto] = cp; |
703 | |
704 | /* use generic ioctl function if not defined by module */ |
705 | if (!cp->ops->ioctl) |
706 | cp->ops->ioctl = can_ioctl; |
707 | } |
708 | spin_unlock(&proto_tab_lock); |
709 | |
710 | if (err < 0) |
711 | proto_unregister(cp->prot); |
712 | |
713 | return err; |
714 | } |
715 | EXPORT_SYMBOL(can_proto_register); |
716 | |
717 | /** |
718 | * can_proto_unregister - unregister CAN transport protocol |
719 | * @cp: pointer to CAN protocol structure |
720 | */ |
721 | void can_proto_unregister(struct can_proto *cp) |
722 | { |
723 | int proto = cp->protocol; |
724 | |
725 | spin_lock(&proto_tab_lock); |
726 | if (!proto_tab[proto]) { |
727 | printk(KERN_ERR "BUG: can: protocol %d is not registered\n", |
728 | proto); |
729 | } |
730 | proto_tab[proto] = NULL; |
731 | spin_unlock(&proto_tab_lock); |
732 | |
733 | proto_unregister(cp->prot); |
734 | } |
735 | EXPORT_SYMBOL(can_proto_unregister); |
736 | |
737 | /* |
738 | * af_can notifier to create/remove CAN netdevice specific structs |
739 | */ |
740 | static int can_notifier(struct notifier_block *nb, unsigned long msg, |
741 | void *data) |
742 | { |
743 | struct net_device *dev = (struct net_device *)data; |
744 | struct dev_rcv_lists *d; |
745 | |
746 | if (!net_eq(dev_net(dev), &init_net)) |
747 | return NOTIFY_DONE; |
748 | |
749 | if (dev->type != ARPHRD_CAN) |
750 | return NOTIFY_DONE; |
751 | |
752 | switch (msg) { |
753 | |
754 | case NETDEV_REGISTER: |
755 | |
756 | /* create new dev_rcv_lists for this device */ |
757 | d = kzalloc(sizeof(*d), GFP_KERNEL); |
758 | if (!d) { |
759 | printk(KERN_ERR |
760 | "can: allocation of receive list failed\n"); |
761 | return NOTIFY_DONE; |
762 | } |
763 | BUG_ON(dev->ml_priv); |
764 | dev->ml_priv = d; |
765 | |
766 | break; |
767 | |
768 | case NETDEV_UNREGISTER: |
769 | spin_lock(&can_rcvlists_lock); |
770 | |
771 | d = dev->ml_priv; |
772 | if (d) { |
773 | if (d->entries) |
774 | d->remove_on_zero_entries = 1; |
775 | else { |
776 | kfree(d); |
777 | dev->ml_priv = NULL; |
778 | } |
779 | } else |
780 | printk(KERN_ERR "can: notifier: receive list not " |
781 | "found for dev %s\n", dev->name); |
782 | |
783 | spin_unlock(&can_rcvlists_lock); |
784 | |
785 | break; |
786 | } |
787 | |
788 | return NOTIFY_DONE; |
789 | } |
790 | |
791 | /* |
792 | * af_can module init/exit functions |
793 | */ |
794 | |
795 | static struct packet_type can_packet __read_mostly = { |
796 | .type = cpu_to_be16(ETH_P_CAN), |
797 | .dev = NULL, |
798 | .func = can_rcv, |
799 | }; |
800 | |
801 | static const struct net_proto_family can_family_ops = { |
802 | .family = PF_CAN, |
803 | .create = can_create, |
804 | .owner = THIS_MODULE, |
805 | }; |
806 | |
807 | /* notifier block for netdevice event */ |
808 | static struct notifier_block can_netdev_notifier __read_mostly = { |
809 | .notifier_call = can_notifier, |
810 | }; |
811 | |
812 | static __init int can_init(void) |
813 | { |
814 | printk(banner); |
815 | |
816 | memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list)); |
817 | |
818 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), |
819 | 0, 0, NULL); |
820 | if (!rcv_cache) |
821 | return -ENOMEM; |
822 | |
823 | if (stats_timer) { |
824 | /* the statistics are updated every second (timer triggered) */ |
825 | setup_timer(&can_stattimer, can_stat_update, 0); |
826 | mod_timer(&can_stattimer, round_jiffies(jiffies + HZ)); |
827 | } else |
828 | can_stattimer.function = NULL; |
829 | |
830 | can_init_proc(); |
831 | |
832 | /* protocol register */ |
833 | sock_register(&can_family_ops); |
834 | register_netdevice_notifier(&can_netdev_notifier); |
835 | dev_add_pack(&can_packet); |
836 | |
837 | return 0; |
838 | } |
839 | |
840 | static __exit void can_exit(void) |
841 | { |
842 | struct net_device *dev; |
843 | |
844 | if (stats_timer) |
845 | del_timer(&can_stattimer); |
846 | |
847 | can_remove_proc(); |
848 | |
849 | /* protocol unregister */ |
850 | dev_remove_pack(&can_packet); |
851 | unregister_netdevice_notifier(&can_netdev_notifier); |
852 | sock_unregister(PF_CAN); |
853 | |
854 | /* remove created dev_rcv_lists from still registered CAN devices */ |
855 | rcu_read_lock(); |
856 | for_each_netdev_rcu(&init_net, dev) { |
857 | if (dev->type == ARPHRD_CAN && dev->ml_priv){ |
858 | |
859 | struct dev_rcv_lists *d = dev->ml_priv; |
860 | |
861 | BUG_ON(d->entries); |
862 | kfree(d); |
863 | dev->ml_priv = NULL; |
864 | } |
865 | } |
866 | rcu_read_unlock(); |
867 | |
868 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
869 | |
870 | kmem_cache_destroy(rcv_cache); |
871 | } |
872 | |
873 | module_init(can_init); |
874 | module_exit(can_exit); |
875 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9