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0d66548a OH |
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 | HLIST_HEAD(can_rx_dev_list); | |
81 | static 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 | { | |
119 | struct sock *sk; | |
120 | struct can_proto *cp; | |
121 | char module_name[sizeof("can-proto-000")]; | |
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 != &init_net) | |
130 | return -EAFNOSUPPORT; | |
131 | ||
132 | /* try to load protocol module, when CONFIG_KMOD is defined */ | |
133 | if (!proto_tab[protocol]) { | |
134 | sprintf(module_name, "can-proto-%d", protocol); | |
135 | err = request_module(module_name); | |
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 == -ENOSYS) { | |
143 | if (printk_ratelimit()) | |
144 | printk(KERN_INFO "can: request_module(%s)" | |
145 | " not implemented.\n", module_name); | |
146 | } else if (err) { | |
147 | if (printk_ratelimit()) | |
148 | printk(KERN_ERR "can: request_module(%s)" | |
149 | " failed.\n", module_name); | |
150 | } | |
151 | } | |
152 | ||
153 | spin_lock(&proto_tab_lock); | |
154 | cp = proto_tab[protocol]; | |
155 | if (cp && !try_module_get(cp->prot->owner)) | |
156 | cp = NULL; | |
157 | spin_unlock(&proto_tab_lock); | |
158 | ||
159 | /* check for available protocol and correct usage */ | |
160 | ||
161 | if (!cp) | |
162 | return -EPROTONOSUPPORT; | |
163 | ||
164 | if (cp->type != sock->type) { | |
165 | err = -EPROTONOSUPPORT; | |
166 | goto errout; | |
167 | } | |
168 | ||
169 | if (cp->capability >= 0 && !capable(cp->capability)) { | |
170 | err = -EPERM; | |
171 | goto errout; | |
172 | } | |
173 | ||
174 | sock->ops = cp->ops; | |
175 | ||
176 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot); | |
177 | if (!sk) { | |
178 | err = -ENOMEM; | |
179 | goto errout; | |
180 | } | |
181 | ||
182 | sock_init_data(sock, sk); | |
183 | sk->sk_destruct = can_sock_destruct; | |
184 | ||
185 | if (sk->sk_prot->init) | |
186 | err = sk->sk_prot->init(sk); | |
187 | ||
188 | if (err) { | |
189 | /* release sk on errors */ | |
190 | sock_orphan(sk); | |
191 | sock_put(sk); | |
192 | } | |
193 | ||
194 | errout: | |
195 | module_put(cp->prot->owner); | |
196 | return err; | |
197 | } | |
198 | ||
199 | /* | |
200 | * af_can tx path | |
201 | */ | |
202 | ||
203 | /** | |
204 | * can_send - transmit a CAN frame (optional with local loopback) | |
205 | * @skb: pointer to socket buffer with CAN frame in data section | |
206 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
207 | * | |
208 | * Return: | |
209 | * 0 on success | |
210 | * -ENETDOWN when the selected interface is down | |
211 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
212 | * -ENOMEM when local loopback failed at calling skb_clone() | |
213 | * -EPERM when trying to send on a non-CAN interface | |
214 | */ | |
215 | int can_send(struct sk_buff *skb, int loop) | |
216 | { | |
217 | int err; | |
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 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); | |
254 | ||
255 | if (!newskb) { | |
256 | kfree_skb(skb); | |
257 | return -ENOMEM; | |
258 | } | |
259 | ||
260 | newskb->sk = skb->sk; | |
261 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
262 | newskb->pkt_type = PACKET_BROADCAST; | |
263 | netif_rx(newskb); | |
264 | } | |
265 | } else { | |
266 | /* indication for the CAN driver: no loopback required */ | |
267 | skb->pkt_type = PACKET_HOST; | |
268 | } | |
269 | ||
270 | /* send to netdevice */ | |
271 | err = dev_queue_xmit(skb); | |
272 | if (err > 0) | |
273 | err = net_xmit_errno(err); | |
274 | ||
275 | /* update statistics */ | |
276 | can_stats.tx_frames++; | |
277 | can_stats.tx_frames_delta++; | |
278 | ||
279 | return err; | |
280 | } | |
281 | EXPORT_SYMBOL(can_send); | |
282 | ||
283 | /* | |
284 | * af_can rx path | |
285 | */ | |
286 | ||
287 | static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) | |
288 | { | |
289 | struct dev_rcv_lists *d = NULL; | |
290 | struct hlist_node *n; | |
291 | ||
292 | /* | |
293 | * find receive list for this device | |
294 | * | |
295 | * The hlist_for_each_entry*() macros curse through the list | |
296 | * using the pointer variable n and set d to the containing | |
297 | * struct in each list iteration. Therefore, after list | |
298 | * iteration, d is unmodified when the list is empty, and it | |
299 | * points to last list element, when the list is non-empty | |
300 | * but no match in the loop body is found. I.e. d is *not* | |
301 | * NULL when no match is found. We can, however, use the | |
302 | * cursor variable n to decide if a match was found. | |
303 | */ | |
304 | ||
305 | hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) { | |
306 | if (d->dev == dev) | |
307 | break; | |
308 | } | |
309 | ||
310 | return n ? d : NULL; | |
311 | } | |
312 | ||
313 | static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, | |
314 | struct dev_rcv_lists *d) | |
315 | { | |
316 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
317 | ||
318 | /* filter error frames */ | |
319 | if (*mask & CAN_ERR_FLAG) { | |
320 | /* clear CAN_ERR_FLAG in list entry */ | |
321 | *mask &= CAN_ERR_MASK; | |
322 | return &d->rx[RX_ERR]; | |
323 | } | |
324 | ||
325 | /* ensure valid values in can_mask */ | |
326 | if (*mask & CAN_EFF_FLAG) | |
327 | *mask &= (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG); | |
328 | else | |
329 | *mask &= (CAN_SFF_MASK | CAN_RTR_FLAG); | |
330 | ||
331 | /* reduce condition testing at receive time */ | |
332 | *can_id &= *mask; | |
333 | ||
334 | /* inverse can_id/can_mask filter */ | |
335 | if (inv) | |
336 | return &d->rx[RX_INV]; | |
337 | ||
338 | /* mask == 0 => no condition testing at receive time */ | |
339 | if (!(*mask)) | |
340 | return &d->rx[RX_ALL]; | |
341 | ||
342 | /* use extra filterset for the subscription of exactly *ONE* can_id */ | |
343 | if (*can_id & CAN_EFF_FLAG) { | |
344 | if (*mask == (CAN_EFF_MASK | CAN_EFF_FLAG)) { | |
345 | /* RFC: a use-case for hash-tables in the future? */ | |
346 | return &d->rx[RX_EFF]; | |
347 | } | |
348 | } else { | |
349 | if (*mask == CAN_SFF_MASK) | |
350 | return &d->rx_sff[*can_id]; | |
351 | } | |
352 | ||
353 | /* default: filter via can_id/can_mask */ | |
354 | return &d->rx[RX_FIL]; | |
355 | } | |
356 | ||
357 | /** | |
358 | * can_rx_register - subscribe CAN frames from a specific interface | |
359 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
360 | * @can_id: CAN identifier (see description) | |
361 | * @mask: CAN mask (see description) | |
362 | * @func: callback function on filter match | |
363 | * @data: returned parameter for callback function | |
364 | * @ident: string for calling module indentification | |
365 | * | |
366 | * Description: | |
367 | * Invokes the callback function with the received sk_buff and the given | |
368 | * parameter 'data' on a matching receive filter. A filter matches, when | |
369 | * | |
370 | * <received_can_id> & mask == can_id & mask | |
371 | * | |
372 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
373 | * filter for error frames (CAN_ERR_FLAG bit set in mask). | |
374 | * | |
375 | * Return: | |
376 | * 0 on success | |
377 | * -ENOMEM on missing cache mem to create subscription entry | |
378 | * -ENODEV unknown device | |
379 | */ | |
380 | int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask, | |
381 | void (*func)(struct sk_buff *, void *), void *data, | |
382 | char *ident) | |
383 | { | |
384 | struct receiver *r; | |
385 | struct hlist_head *rl; | |
386 | struct dev_rcv_lists *d; | |
387 | int err = 0; | |
388 | ||
389 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
390 | ||
391 | r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); | |
392 | if (!r) | |
393 | return -ENOMEM; | |
394 | ||
395 | spin_lock(&can_rcvlists_lock); | |
396 | ||
397 | d = find_dev_rcv_lists(dev); | |
398 | if (d) { | |
399 | rl = find_rcv_list(&can_id, &mask, d); | |
400 | ||
401 | r->can_id = can_id; | |
402 | r->mask = mask; | |
403 | r->matches = 0; | |
404 | r->func = func; | |
405 | r->data = data; | |
406 | r->ident = ident; | |
407 | ||
408 | hlist_add_head_rcu(&r->list, rl); | |
409 | d->entries++; | |
410 | ||
411 | can_pstats.rcv_entries++; | |
412 | if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) | |
413 | can_pstats.rcv_entries_max = can_pstats.rcv_entries; | |
414 | } else { | |
415 | kmem_cache_free(rcv_cache, r); | |
416 | err = -ENODEV; | |
417 | } | |
418 | ||
419 | spin_unlock(&can_rcvlists_lock); | |
420 | ||
421 | return err; | |
422 | } | |
423 | EXPORT_SYMBOL(can_rx_register); | |
424 | ||
425 | /* | |
426 | * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal | |
427 | */ | |
428 | static void can_rx_delete_device(struct rcu_head *rp) | |
429 | { | |
430 | struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu); | |
431 | ||
432 | kfree(d); | |
433 | } | |
434 | ||
435 | /* | |
436 | * can_rx_delete_receiver - rcu callback for single receiver entry removal | |
437 | */ | |
438 | static void can_rx_delete_receiver(struct rcu_head *rp) | |
439 | { | |
440 | struct receiver *r = container_of(rp, struct receiver, rcu); | |
441 | ||
442 | kmem_cache_free(rcv_cache, r); | |
443 | } | |
444 | ||
445 | /** | |
446 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
447 | * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list) | |
448 | * @can_id: CAN identifier | |
449 | * @mask: CAN mask | |
450 | * @func: callback function on filter match | |
451 | * @data: returned parameter for callback function | |
452 | * | |
453 | * Description: | |
454 | * Removes subscription entry depending on given (subscription) values. | |
455 | */ | |
456 | void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, | |
457 | void (*func)(struct sk_buff *, void *), void *data) | |
458 | { | |
459 | struct receiver *r = NULL; | |
460 | struct hlist_head *rl; | |
461 | struct hlist_node *next; | |
462 | struct dev_rcv_lists *d; | |
463 | ||
464 | spin_lock(&can_rcvlists_lock); | |
465 | ||
466 | d = find_dev_rcv_lists(dev); | |
467 | if (!d) { | |
468 | printk(KERN_ERR "BUG: receive list not found for " | |
469 | "dev %s, id %03X, mask %03X\n", | |
470 | DNAME(dev), can_id, mask); | |
471 | goto out; | |
472 | } | |
473 | ||
474 | rl = find_rcv_list(&can_id, &mask, d); | |
475 | ||
476 | /* | |
477 | * Search the receiver list for the item to delete. This should | |
478 | * exist, since no receiver may be unregistered that hasn't | |
479 | * been registered before. | |
480 | */ | |
481 | ||
482 | hlist_for_each_entry_rcu(r, next, rl, list) { | |
483 | if (r->can_id == can_id && r->mask == mask | |
484 | && r->func == func && r->data == data) | |
485 | break; | |
486 | } | |
487 | ||
488 | /* | |
489 | * Check for bugs in CAN protocol implementations: | |
490 | * If no matching list item was found, the list cursor variable next | |
491 | * will be NULL, while r will point to the last item of the list. | |
492 | */ | |
493 | ||
494 | if (!next) { | |
495 | printk(KERN_ERR "BUG: receive list entry not found for " | |
496 | "dev %s, id %03X, mask %03X\n", | |
497 | DNAME(dev), can_id, mask); | |
498 | r = NULL; | |
499 | d = NULL; | |
500 | goto out; | |
501 | } | |
502 | ||
503 | hlist_del_rcu(&r->list); | |
504 | d->entries--; | |
505 | ||
506 | if (can_pstats.rcv_entries > 0) | |
507 | can_pstats.rcv_entries--; | |
508 | ||
509 | /* remove device structure requested by NETDEV_UNREGISTER */ | |
510 | if (d->remove_on_zero_entries && !d->entries) | |
511 | hlist_del_rcu(&d->list); | |
512 | else | |
513 | d = NULL; | |
514 | ||
515 | out: | |
516 | spin_unlock(&can_rcvlists_lock); | |
517 | ||
518 | /* schedule the receiver item for deletion */ | |
519 | if (r) | |
520 | call_rcu(&r->rcu, can_rx_delete_receiver); | |
521 | ||
522 | /* schedule the device structure for deletion */ | |
523 | if (d) | |
524 | call_rcu(&d->rcu, can_rx_delete_device); | |
525 | } | |
526 | EXPORT_SYMBOL(can_rx_unregister); | |
527 | ||
528 | static inline void deliver(struct sk_buff *skb, struct receiver *r) | |
529 | { | |
530 | struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC); | |
531 | ||
532 | if (clone) { | |
533 | clone->sk = skb->sk; | |
534 | r->func(clone, r->data); | |
535 | r->matches++; | |
536 | } | |
537 | } | |
538 | ||
539 | static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) | |
540 | { | |
541 | struct receiver *r; | |
542 | struct hlist_node *n; | |
543 | int matches = 0; | |
544 | struct can_frame *cf = (struct can_frame *)skb->data; | |
545 | canid_t can_id = cf->can_id; | |
546 | ||
547 | if (d->entries == 0) | |
548 | return 0; | |
549 | ||
550 | if (can_id & CAN_ERR_FLAG) { | |
551 | /* check for error frame entries only */ | |
552 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) { | |
553 | if (can_id & r->mask) { | |
554 | deliver(skb, r); | |
555 | matches++; | |
556 | } | |
557 | } | |
558 | return matches; | |
559 | } | |
560 | ||
561 | /* check for unfiltered entries */ | |
562 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) { | |
563 | deliver(skb, r); | |
564 | matches++; | |
565 | } | |
566 | ||
567 | /* check for can_id/mask entries */ | |
568 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) { | |
569 | if ((can_id & r->mask) == r->can_id) { | |
570 | deliver(skb, r); | |
571 | matches++; | |
572 | } | |
573 | } | |
574 | ||
575 | /* check for inverted can_id/mask entries */ | |
576 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) { | |
577 | if ((can_id & r->mask) != r->can_id) { | |
578 | deliver(skb, r); | |
579 | matches++; | |
580 | } | |
581 | } | |
582 | ||
583 | /* check CAN_ID specific entries */ | |
584 | if (can_id & CAN_EFF_FLAG) { | |
585 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) { | |
586 | if (r->can_id == can_id) { | |
587 | deliver(skb, r); | |
588 | matches++; | |
589 | } | |
590 | } | |
591 | } else { | |
592 | can_id &= CAN_SFF_MASK; | |
593 | hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) { | |
594 | deliver(skb, r); | |
595 | matches++; | |
596 | } | |
597 | } | |
598 | ||
599 | return matches; | |
600 | } | |
601 | ||
602 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
603 | struct packet_type *pt, struct net_device *orig_dev) | |
604 | { | |
605 | struct dev_rcv_lists *d; | |
606 | int matches; | |
607 | ||
608 | if (dev->type != ARPHRD_CAN || dev->nd_net != &init_net) { | |
609 | kfree_skb(skb); | |
610 | return 0; | |
611 | } | |
612 | ||
613 | /* update statistics */ | |
614 | can_stats.rx_frames++; | |
615 | can_stats.rx_frames_delta++; | |
616 | ||
617 | rcu_read_lock(); | |
618 | ||
619 | /* deliver the packet to sockets listening on all devices */ | |
620 | matches = can_rcv_filter(&can_rx_alldev_list, skb); | |
621 | ||
622 | /* find receive list for this device */ | |
623 | d = find_dev_rcv_lists(dev); | |
624 | if (d) | |
625 | matches += can_rcv_filter(d, skb); | |
626 | ||
627 | rcu_read_unlock(); | |
628 | ||
629 | /* free the skbuff allocated by the netdevice driver */ | |
630 | kfree_skb(skb); | |
631 | ||
632 | if (matches > 0) { | |
633 | can_stats.matches++; | |
634 | can_stats.matches_delta++; | |
635 | } | |
636 | ||
637 | return 0; | |
638 | } | |
639 | ||
640 | /* | |
641 | * af_can protocol functions | |
642 | */ | |
643 | ||
644 | /** | |
645 | * can_proto_register - register CAN transport protocol | |
646 | * @cp: pointer to CAN protocol structure | |
647 | * | |
648 | * Return: | |
649 | * 0 on success | |
650 | * -EINVAL invalid (out of range) protocol number | |
651 | * -EBUSY protocol already in use | |
652 | * -ENOBUF if proto_register() fails | |
653 | */ | |
654 | int can_proto_register(struct can_proto *cp) | |
655 | { | |
656 | int proto = cp->protocol; | |
657 | int err = 0; | |
658 | ||
659 | if (proto < 0 || proto >= CAN_NPROTO) { | |
660 | printk(KERN_ERR "can: protocol number %d out of range\n", | |
661 | proto); | |
662 | return -EINVAL; | |
663 | } | |
664 | ||
665 | spin_lock(&proto_tab_lock); | |
666 | if (proto_tab[proto]) { | |
667 | printk(KERN_ERR "can: protocol %d already registered\n", | |
668 | proto); | |
669 | err = -EBUSY; | |
670 | goto errout; | |
671 | } | |
672 | ||
673 | err = proto_register(cp->prot, 0); | |
674 | if (err < 0) | |
675 | goto errout; | |
676 | ||
677 | proto_tab[proto] = cp; | |
678 | ||
679 | /* use generic ioctl function if the module doesn't bring its own */ | |
680 | if (!cp->ops->ioctl) | |
681 | cp->ops->ioctl = can_ioctl; | |
682 | ||
683 | errout: | |
684 | spin_unlock(&proto_tab_lock); | |
685 | ||
686 | return err; | |
687 | } | |
688 | EXPORT_SYMBOL(can_proto_register); | |
689 | ||
690 | /** | |
691 | * can_proto_unregister - unregister CAN transport protocol | |
692 | * @cp: pointer to CAN protocol structure | |
693 | */ | |
694 | void can_proto_unregister(struct can_proto *cp) | |
695 | { | |
696 | int proto = cp->protocol; | |
697 | ||
698 | spin_lock(&proto_tab_lock); | |
699 | if (!proto_tab[proto]) { | |
700 | printk(KERN_ERR "BUG: can: protocol %d is not registered\n", | |
701 | proto); | |
702 | } | |
703 | proto_unregister(cp->prot); | |
704 | proto_tab[proto] = NULL; | |
705 | spin_unlock(&proto_tab_lock); | |
706 | } | |
707 | EXPORT_SYMBOL(can_proto_unregister); | |
708 | ||
709 | /* | |
710 | * af_can notifier to create/remove CAN netdevice specific structs | |
711 | */ | |
712 | static int can_notifier(struct notifier_block *nb, unsigned long msg, | |
713 | void *data) | |
714 | { | |
715 | struct net_device *dev = (struct net_device *)data; | |
716 | struct dev_rcv_lists *d; | |
717 | ||
718 | if (dev->nd_net != &init_net) | |
719 | return NOTIFY_DONE; | |
720 | ||
721 | if (dev->type != ARPHRD_CAN) | |
722 | return NOTIFY_DONE; | |
723 | ||
724 | switch (msg) { | |
725 | ||
726 | case NETDEV_REGISTER: | |
727 | ||
728 | /* | |
729 | * create new dev_rcv_lists for this device | |
730 | * | |
731 | * N.B. zeroing the struct is the correct initialization | |
732 | * for the embedded hlist_head structs. | |
733 | * Another list type, e.g. list_head, would require | |
734 | * explicit initialization. | |
735 | */ | |
736 | ||
737 | d = kzalloc(sizeof(*d), GFP_KERNEL); | |
738 | if (!d) { | |
739 | printk(KERN_ERR | |
740 | "can: allocation of receive list failed\n"); | |
741 | return NOTIFY_DONE; | |
742 | } | |
743 | d->dev = dev; | |
744 | ||
745 | spin_lock(&can_rcvlists_lock); | |
746 | hlist_add_head_rcu(&d->list, &can_rx_dev_list); | |
747 | spin_unlock(&can_rcvlists_lock); | |
748 | ||
749 | break; | |
750 | ||
751 | case NETDEV_UNREGISTER: | |
752 | spin_lock(&can_rcvlists_lock); | |
753 | ||
754 | d = find_dev_rcv_lists(dev); | |
755 | if (d) { | |
756 | if (d->entries) { | |
757 | d->remove_on_zero_entries = 1; | |
758 | d = NULL; | |
759 | } else | |
760 | hlist_del_rcu(&d->list); | |
761 | } else | |
762 | printk(KERN_ERR "can: notifier: receive list not " | |
763 | "found for dev %s\n", dev->name); | |
764 | ||
765 | spin_unlock(&can_rcvlists_lock); | |
766 | ||
767 | if (d) | |
768 | call_rcu(&d->rcu, can_rx_delete_device); | |
769 | ||
770 | break; | |
771 | } | |
772 | ||
773 | return NOTIFY_DONE; | |
774 | } | |
775 | ||
776 | /* | |
777 | * af_can module init/exit functions | |
778 | */ | |
779 | ||
780 | static struct packet_type can_packet __read_mostly = { | |
781 | .type = __constant_htons(ETH_P_CAN), | |
782 | .dev = NULL, | |
783 | .func = can_rcv, | |
784 | }; | |
785 | ||
786 | static struct net_proto_family can_family_ops __read_mostly = { | |
787 | .family = PF_CAN, | |
788 | .create = can_create, | |
789 | .owner = THIS_MODULE, | |
790 | }; | |
791 | ||
792 | /* notifier block for netdevice event */ | |
793 | static struct notifier_block can_netdev_notifier __read_mostly = { | |
794 | .notifier_call = can_notifier, | |
795 | }; | |
796 | ||
797 | static __init int can_init(void) | |
798 | { | |
799 | printk(banner); | |
800 | ||
801 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), | |
802 | 0, 0, NULL); | |
803 | if (!rcv_cache) | |
804 | return -ENOMEM; | |
805 | ||
806 | /* | |
807 | * Insert can_rx_alldev_list for reception on all devices. | |
808 | * This struct is zero initialized which is correct for the | |
809 | * embedded hlist heads, the dev pointer, and the entries counter. | |
810 | */ | |
811 | ||
812 | spin_lock(&can_rcvlists_lock); | |
813 | hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list); | |
814 | spin_unlock(&can_rcvlists_lock); | |
815 | ||
816 | if (stats_timer) { | |
817 | /* the statistics are updated every second (timer triggered) */ | |
818 | setup_timer(&can_stattimer, can_stat_update, 0); | |
819 | mod_timer(&can_stattimer, round_jiffies(jiffies + HZ)); | |
820 | } else | |
821 | can_stattimer.function = NULL; | |
822 | ||
823 | can_init_proc(); | |
824 | ||
825 | /* protocol register */ | |
826 | sock_register(&can_family_ops); | |
827 | register_netdevice_notifier(&can_netdev_notifier); | |
828 | dev_add_pack(&can_packet); | |
829 | ||
830 | return 0; | |
831 | } | |
832 | ||
833 | static __exit void can_exit(void) | |
834 | { | |
835 | struct dev_rcv_lists *d; | |
836 | struct hlist_node *n, *next; | |
837 | ||
838 | if (stats_timer) | |
839 | del_timer(&can_stattimer); | |
840 | ||
841 | can_remove_proc(); | |
842 | ||
843 | /* protocol unregister */ | |
844 | dev_remove_pack(&can_packet); | |
845 | unregister_netdevice_notifier(&can_netdev_notifier); | |
846 | sock_unregister(PF_CAN); | |
847 | ||
848 | /* remove can_rx_dev_list */ | |
849 | spin_lock(&can_rcvlists_lock); | |
850 | hlist_del(&can_rx_alldev_list.list); | |
851 | hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) { | |
852 | hlist_del(&d->list); | |
853 | kfree(d); | |
854 | } | |
855 | spin_unlock(&can_rcvlists_lock); | |
856 | ||
857 | kmem_cache_destroy(rcv_cache); | |
858 | } | |
859 | ||
860 | module_init(can_init); | |
861 | module_exit(can_exit); |