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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; | |
0d66548a OH |
121 | int err = 0; |
122 | ||
123 | sock->state = SS_UNCONNECTED; | |
124 | ||
125 | if (protocol < 0 || protocol >= CAN_NPROTO) | |
126 | return -EINVAL; | |
127 | ||
128 | if (net != &init_net) | |
129 | return -EAFNOSUPPORT; | |
130 | ||
95a5afca JB |
131 | #ifdef CONFIG_MODULES |
132 | /* try to load protocol module kernel is modular */ | |
0d66548a | 133 | if (!proto_tab[protocol]) { |
5423dd67 | 134 | err = request_module("can-proto-%d", protocol); |
0d66548a OH |
135 | |
136 | /* | |
137 | * In case of error we only print a message but don't | |
138 | * return the error code immediately. Below we will | |
139 | * return -EPROTONOSUPPORT | |
140 | */ | |
5423dd67 UT |
141 | if (err && printk_ratelimit()) |
142 | printk(KERN_ERR "can: request_module " | |
143 | "(can-proto-%d) failed.\n", protocol); | |
0d66548a | 144 | } |
5423dd67 | 145 | #endif |
0d66548a OH |
146 | |
147 | spin_lock(&proto_tab_lock); | |
148 | cp = proto_tab[protocol]; | |
149 | if (cp && !try_module_get(cp->prot->owner)) | |
150 | cp = NULL; | |
151 | spin_unlock(&proto_tab_lock); | |
152 | ||
153 | /* check for available protocol and correct usage */ | |
154 | ||
155 | if (!cp) | |
156 | return -EPROTONOSUPPORT; | |
157 | ||
158 | if (cp->type != sock->type) { | |
159 | err = -EPROTONOSUPPORT; | |
160 | goto errout; | |
161 | } | |
162 | ||
0d66548a OH |
163 | sock->ops = cp->ops; |
164 | ||
165 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot); | |
166 | if (!sk) { | |
167 | err = -ENOMEM; | |
168 | goto errout; | |
169 | } | |
170 | ||
171 | sock_init_data(sock, sk); | |
172 | sk->sk_destruct = can_sock_destruct; | |
173 | ||
174 | if (sk->sk_prot->init) | |
175 | err = sk->sk_prot->init(sk); | |
176 | ||
177 | if (err) { | |
178 | /* release sk on errors */ | |
179 | sock_orphan(sk); | |
180 | sock_put(sk); | |
181 | } | |
182 | ||
183 | errout: | |
184 | module_put(cp->prot->owner); | |
185 | return err; | |
186 | } | |
187 | ||
188 | /* | |
189 | * af_can tx path | |
190 | */ | |
191 | ||
192 | /** | |
193 | * can_send - transmit a CAN frame (optional with local loopback) | |
194 | * @skb: pointer to socket buffer with CAN frame in data section | |
195 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
196 | * | |
481a8199 OH |
197 | * Due to the loopback this routine must not be called from hardirq context. |
198 | * | |
0d66548a OH |
199 | * Return: |
200 | * 0 on success | |
201 | * -ENETDOWN when the selected interface is down | |
202 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
203 | * -ENOMEM when local loopback failed at calling skb_clone() | |
204 | * -EPERM when trying to send on a non-CAN interface | |
7f2d38eb | 205 | * -EINVAL when the skb->data does not contain a valid CAN frame |
0d66548a OH |
206 | */ |
207 | int can_send(struct sk_buff *skb, int loop) | |
208 | { | |
c2ab7ac2 | 209 | struct sk_buff *newskb = NULL; |
7f2d38eb | 210 | struct can_frame *cf = (struct can_frame *)skb->data; |
0d66548a OH |
211 | int err; |
212 | ||
7f2d38eb OH |
213 | if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) { |
214 | kfree_skb(skb); | |
215 | return -EINVAL; | |
216 | } | |
217 | ||
0d66548a OH |
218 | if (skb->dev->type != ARPHRD_CAN) { |
219 | kfree_skb(skb); | |
220 | return -EPERM; | |
221 | } | |
222 | ||
223 | if (!(skb->dev->flags & IFF_UP)) { | |
224 | kfree_skb(skb); | |
225 | return -ENETDOWN; | |
226 | } | |
227 | ||
228 | skb->protocol = htons(ETH_P_CAN); | |
229 | skb_reset_network_header(skb); | |
230 | skb_reset_transport_header(skb); | |
231 | ||
232 | if (loop) { | |
233 | /* local loopback of sent CAN frames */ | |
234 | ||
235 | /* indication for the CAN driver: do loopback */ | |
236 | skb->pkt_type = PACKET_LOOPBACK; | |
237 | ||
238 | /* | |
239 | * The reference to the originating sock may be required | |
240 | * by the receiving socket to check whether the frame is | |
241 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS | |
242 | * Therefore we have to ensure that skb->sk remains the | |
243 | * reference to the originating sock by restoring skb->sk | |
244 | * after each skb_clone() or skb_orphan() usage. | |
245 | */ | |
246 | ||
247 | if (!(skb->dev->flags & IFF_ECHO)) { | |
248 | /* | |
249 | * If the interface is not capable to do loopback | |
250 | * itself, we do it here. | |
251 | */ | |
c2ab7ac2 | 252 | newskb = skb_clone(skb, GFP_ATOMIC); |
0d66548a OH |
253 | if (!newskb) { |
254 | kfree_skb(skb); | |
255 | return -ENOMEM; | |
256 | } | |
257 | ||
258 | newskb->sk = skb->sk; | |
259 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
260 | newskb->pkt_type = PACKET_BROADCAST; | |
0d66548a OH |
261 | } |
262 | } else { | |
263 | /* indication for the CAN driver: no loopback required */ | |
264 | skb->pkt_type = PACKET_HOST; | |
265 | } | |
266 | ||
267 | /* send to netdevice */ | |
268 | err = dev_queue_xmit(skb); | |
269 | if (err > 0) | |
270 | err = net_xmit_errno(err); | |
271 | ||
c2ab7ac2 | 272 | if (err) { |
ce030edf | 273 | kfree_skb(newskb); |
c2ab7ac2 OH |
274 | return err; |
275 | } | |
276 | ||
277 | if (newskb) | |
481a8199 | 278 | netif_rx_ni(newskb); |
c2ab7ac2 | 279 | |
0d66548a OH |
280 | /* update statistics */ |
281 | can_stats.tx_frames++; | |
282 | can_stats.tx_frames_delta++; | |
283 | ||
c2ab7ac2 | 284 | return 0; |
0d66548a OH |
285 | } |
286 | EXPORT_SYMBOL(can_send); | |
287 | ||
288 | /* | |
289 | * af_can rx path | |
290 | */ | |
291 | ||
292 | static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) | |
293 | { | |
294 | struct dev_rcv_lists *d = NULL; | |
295 | struct hlist_node *n; | |
296 | ||
297 | /* | |
298 | * find receive list for this device | |
299 | * | |
300 | * The hlist_for_each_entry*() macros curse through the list | |
301 | * using the pointer variable n and set d to the containing | |
302 | * struct in each list iteration. Therefore, after list | |
303 | * iteration, d is unmodified when the list is empty, and it | |
304 | * points to last list element, when the list is non-empty | |
305 | * but no match in the loop body is found. I.e. d is *not* | |
306 | * NULL when no match is found. We can, however, use the | |
307 | * cursor variable n to decide if a match was found. | |
308 | */ | |
309 | ||
310 | hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) { | |
311 | if (d->dev == dev) | |
312 | break; | |
313 | } | |
314 | ||
315 | return n ? d : NULL; | |
316 | } | |
317 | ||
d253eee2 OH |
318 | /** |
319 | * find_rcv_list - determine optimal filterlist inside device filter struct | |
320 | * @can_id: pointer to CAN identifier of a given can_filter | |
321 | * @mask: pointer to CAN mask of a given can_filter | |
322 | * @d: pointer to the device filter struct | |
323 | * | |
324 | * Description: | |
325 | * Returns the optimal filterlist to reduce the filter handling in the | |
326 | * receive path. This function is called by service functions that need | |
327 | * to register or unregister a can_filter in the filter lists. | |
328 | * | |
329 | * A filter matches in general, when | |
330 | * | |
331 | * <received_can_id> & mask == can_id & mask | |
332 | * | |
333 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe | |
334 | * relevant bits for the filter. | |
335 | * | |
336 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
337 | * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames | |
338 | * there is a special filterlist and a special rx path filter handling. | |
339 | * | |
340 | * Return: | |
341 | * Pointer to optimal filterlist for the given can_id/mask pair. | |
342 | * Constistency checked mask. | |
343 | * Reduced can_id to have a preprocessed filter compare value. | |
344 | */ | |
0d66548a OH |
345 | static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, |
346 | struct dev_rcv_lists *d) | |
347 | { | |
348 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
349 | ||
d253eee2 | 350 | /* filter for error frames in extra filterlist */ |
0d66548a | 351 | if (*mask & CAN_ERR_FLAG) { |
d253eee2 | 352 | /* clear CAN_ERR_FLAG in filter entry */ |
0d66548a OH |
353 | *mask &= CAN_ERR_MASK; |
354 | return &d->rx[RX_ERR]; | |
355 | } | |
356 | ||
d253eee2 OH |
357 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
358 | ||
359 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) | |
360 | ||
361 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ | |
362 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) | |
363 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); | |
0d66548a OH |
364 | |
365 | /* reduce condition testing at receive time */ | |
366 | *can_id &= *mask; | |
367 | ||
368 | /* inverse can_id/can_mask filter */ | |
369 | if (inv) | |
370 | return &d->rx[RX_INV]; | |
371 | ||
372 | /* mask == 0 => no condition testing at receive time */ | |
373 | if (!(*mask)) | |
374 | return &d->rx[RX_ALL]; | |
375 | ||
d253eee2 OH |
376 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
377 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) | |
378 | && !(*can_id & CAN_RTR_FLAG)) { | |
379 | ||
380 | if (*can_id & CAN_EFF_FLAG) { | |
381 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) { | |
382 | /* RFC: a future use-case for hash-tables? */ | |
383 | return &d->rx[RX_EFF]; | |
384 | } | |
385 | } else { | |
386 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) | |
387 | return &d->rx_sff[*can_id]; | |
0d66548a | 388 | } |
0d66548a OH |
389 | } |
390 | ||
391 | /* default: filter via can_id/can_mask */ | |
392 | return &d->rx[RX_FIL]; | |
393 | } | |
394 | ||
395 | /** | |
396 | * can_rx_register - subscribe CAN frames from a specific interface | |
397 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
398 | * @can_id: CAN identifier (see description) | |
399 | * @mask: CAN mask (see description) | |
400 | * @func: callback function on filter match | |
401 | * @data: returned parameter for callback function | |
402 | * @ident: string for calling module indentification | |
403 | * | |
404 | * Description: | |
405 | * Invokes the callback function with the received sk_buff and the given | |
406 | * parameter 'data' on a matching receive filter. A filter matches, when | |
407 | * | |
408 | * <received_can_id> & mask == can_id & mask | |
409 | * | |
410 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
411 | * filter for error frames (CAN_ERR_FLAG bit set in mask). | |
412 | * | |
1fa17d4b OH |
413 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
414 | * the callback function is running. The callback function must *not* free | |
415 | * the given sk_buff while processing it's task. When the given sk_buff is | |
416 | * needed after the end of the callback function it must be cloned inside | |
417 | * the callback function with skb_clone(). | |
418 | * | |
0d66548a OH |
419 | * Return: |
420 | * 0 on success | |
421 | * -ENOMEM on missing cache mem to create subscription entry | |
422 | * -ENODEV unknown device | |
423 | */ | |
424 | int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask, | |
425 | void (*func)(struct sk_buff *, void *), void *data, | |
426 | char *ident) | |
427 | { | |
428 | struct receiver *r; | |
429 | struct hlist_head *rl; | |
430 | struct dev_rcv_lists *d; | |
431 | int err = 0; | |
432 | ||
433 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
434 | ||
435 | r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); | |
436 | if (!r) | |
437 | return -ENOMEM; | |
438 | ||
439 | spin_lock(&can_rcvlists_lock); | |
440 | ||
441 | d = find_dev_rcv_lists(dev); | |
442 | if (d) { | |
443 | rl = find_rcv_list(&can_id, &mask, d); | |
444 | ||
445 | r->can_id = can_id; | |
446 | r->mask = mask; | |
447 | r->matches = 0; | |
448 | r->func = func; | |
449 | r->data = data; | |
450 | r->ident = ident; | |
451 | ||
452 | hlist_add_head_rcu(&r->list, rl); | |
453 | d->entries++; | |
454 | ||
455 | can_pstats.rcv_entries++; | |
456 | if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) | |
457 | can_pstats.rcv_entries_max = can_pstats.rcv_entries; | |
458 | } else { | |
459 | kmem_cache_free(rcv_cache, r); | |
460 | err = -ENODEV; | |
461 | } | |
462 | ||
463 | spin_unlock(&can_rcvlists_lock); | |
464 | ||
465 | return err; | |
466 | } | |
467 | EXPORT_SYMBOL(can_rx_register); | |
468 | ||
469 | /* | |
470 | * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal | |
471 | */ | |
472 | static void can_rx_delete_device(struct rcu_head *rp) | |
473 | { | |
474 | struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu); | |
475 | ||
476 | kfree(d); | |
477 | } | |
478 | ||
479 | /* | |
480 | * can_rx_delete_receiver - rcu callback for single receiver entry removal | |
481 | */ | |
482 | static void can_rx_delete_receiver(struct rcu_head *rp) | |
483 | { | |
484 | struct receiver *r = container_of(rp, struct receiver, rcu); | |
485 | ||
486 | kmem_cache_free(rcv_cache, r); | |
487 | } | |
488 | ||
489 | /** | |
490 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
491 | * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list) | |
492 | * @can_id: CAN identifier | |
493 | * @mask: CAN mask | |
494 | * @func: callback function on filter match | |
495 | * @data: returned parameter for callback function | |
496 | * | |
497 | * Description: | |
498 | * Removes subscription entry depending on given (subscription) values. | |
499 | */ | |
500 | void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, | |
501 | void (*func)(struct sk_buff *, void *), void *data) | |
502 | { | |
503 | struct receiver *r = NULL; | |
504 | struct hlist_head *rl; | |
505 | struct hlist_node *next; | |
506 | struct dev_rcv_lists *d; | |
507 | ||
508 | spin_lock(&can_rcvlists_lock); | |
509 | ||
510 | d = find_dev_rcv_lists(dev); | |
511 | if (!d) { | |
512 | printk(KERN_ERR "BUG: receive list not found for " | |
513 | "dev %s, id %03X, mask %03X\n", | |
514 | DNAME(dev), can_id, mask); | |
515 | goto out; | |
516 | } | |
517 | ||
518 | rl = find_rcv_list(&can_id, &mask, d); | |
519 | ||
520 | /* | |
521 | * Search the receiver list for the item to delete. This should | |
522 | * exist, since no receiver may be unregistered that hasn't | |
523 | * been registered before. | |
524 | */ | |
525 | ||
526 | hlist_for_each_entry_rcu(r, next, rl, list) { | |
527 | if (r->can_id == can_id && r->mask == mask | |
528 | && r->func == func && r->data == data) | |
529 | break; | |
530 | } | |
531 | ||
532 | /* | |
533 | * Check for bugs in CAN protocol implementations: | |
534 | * If no matching list item was found, the list cursor variable next | |
535 | * will be NULL, while r will point to the last item of the list. | |
536 | */ | |
537 | ||
538 | if (!next) { | |
539 | printk(KERN_ERR "BUG: receive list entry not found for " | |
540 | "dev %s, id %03X, mask %03X\n", | |
541 | DNAME(dev), can_id, mask); | |
542 | r = NULL; | |
543 | d = NULL; | |
544 | goto out; | |
545 | } | |
546 | ||
547 | hlist_del_rcu(&r->list); | |
548 | d->entries--; | |
549 | ||
550 | if (can_pstats.rcv_entries > 0) | |
551 | can_pstats.rcv_entries--; | |
552 | ||
553 | /* remove device structure requested by NETDEV_UNREGISTER */ | |
554 | if (d->remove_on_zero_entries && !d->entries) | |
555 | hlist_del_rcu(&d->list); | |
556 | else | |
557 | d = NULL; | |
558 | ||
559 | out: | |
560 | spin_unlock(&can_rcvlists_lock); | |
561 | ||
562 | /* schedule the receiver item for deletion */ | |
563 | if (r) | |
564 | call_rcu(&r->rcu, can_rx_delete_receiver); | |
565 | ||
566 | /* schedule the device structure for deletion */ | |
567 | if (d) | |
568 | call_rcu(&d->rcu, can_rx_delete_device); | |
569 | } | |
570 | EXPORT_SYMBOL(can_rx_unregister); | |
571 | ||
572 | static inline void deliver(struct sk_buff *skb, struct receiver *r) | |
573 | { | |
1fa17d4b OH |
574 | r->func(skb, r->data); |
575 | r->matches++; | |
0d66548a OH |
576 | } |
577 | ||
578 | static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) | |
579 | { | |
580 | struct receiver *r; | |
581 | struct hlist_node *n; | |
582 | int matches = 0; | |
583 | struct can_frame *cf = (struct can_frame *)skb->data; | |
584 | canid_t can_id = cf->can_id; | |
585 | ||
586 | if (d->entries == 0) | |
587 | return 0; | |
588 | ||
589 | if (can_id & CAN_ERR_FLAG) { | |
590 | /* check for error frame entries only */ | |
591 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) { | |
592 | if (can_id & r->mask) { | |
593 | deliver(skb, r); | |
594 | matches++; | |
595 | } | |
596 | } | |
597 | return matches; | |
598 | } | |
599 | ||
600 | /* check for unfiltered entries */ | |
601 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) { | |
602 | deliver(skb, r); | |
603 | matches++; | |
604 | } | |
605 | ||
606 | /* check for can_id/mask entries */ | |
607 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) { | |
608 | if ((can_id & r->mask) == r->can_id) { | |
609 | deliver(skb, r); | |
610 | matches++; | |
611 | } | |
612 | } | |
613 | ||
614 | /* check for inverted can_id/mask entries */ | |
615 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) { | |
616 | if ((can_id & r->mask) != r->can_id) { | |
617 | deliver(skb, r); | |
618 | matches++; | |
619 | } | |
620 | } | |
621 | ||
f706644d OH |
622 | /* check filterlists for single non-RTR can_ids */ |
623 | if (can_id & CAN_RTR_FLAG) | |
624 | return matches; | |
625 | ||
0d66548a OH |
626 | if (can_id & CAN_EFF_FLAG) { |
627 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) { | |
628 | if (r->can_id == can_id) { | |
629 | deliver(skb, r); | |
630 | matches++; | |
631 | } | |
632 | } | |
633 | } else { | |
634 | can_id &= CAN_SFF_MASK; | |
635 | hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) { | |
636 | deliver(skb, r); | |
637 | matches++; | |
638 | } | |
639 | } | |
640 | ||
641 | return matches; | |
642 | } | |
643 | ||
644 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
645 | struct packet_type *pt, struct net_device *orig_dev) | |
646 | { | |
647 | struct dev_rcv_lists *d; | |
7f2d38eb | 648 | struct can_frame *cf = (struct can_frame *)skb->data; |
0d66548a OH |
649 | int matches; |
650 | ||
1758c094 OH |
651 | if (!net_eq(dev_net(dev), &init_net)) |
652 | goto drop; | |
0d66548a | 653 | |
1758c094 OH |
654 | if (WARN_ONCE(dev->type != ARPHRD_CAN || |
655 | skb->len != sizeof(struct can_frame) || | |
656 | cf->can_dlc > 8, | |
657 | "PF_CAN: dropped non conform skbuf: " | |
658 | "dev type %d, len %d, can_dlc %d\n", | |
659 | dev->type, skb->len, cf->can_dlc)) | |
660 | goto drop; | |
7f2d38eb | 661 | |
0d66548a OH |
662 | /* update statistics */ |
663 | can_stats.rx_frames++; | |
664 | can_stats.rx_frames_delta++; | |
665 | ||
666 | rcu_read_lock(); | |
667 | ||
668 | /* deliver the packet to sockets listening on all devices */ | |
669 | matches = can_rcv_filter(&can_rx_alldev_list, skb); | |
670 | ||
671 | /* find receive list for this device */ | |
672 | d = find_dev_rcv_lists(dev); | |
673 | if (d) | |
674 | matches += can_rcv_filter(d, skb); | |
675 | ||
676 | rcu_read_unlock(); | |
677 | ||
62bcaa13 OH |
678 | /* consume the skbuff allocated by the netdevice driver */ |
679 | consume_skb(skb); | |
0d66548a OH |
680 | |
681 | if (matches > 0) { | |
682 | can_stats.matches++; | |
683 | can_stats.matches_delta++; | |
684 | } | |
685 | ||
6ca8b990 | 686 | return NET_RX_SUCCESS; |
1758c094 OH |
687 | |
688 | drop: | |
689 | kfree_skb(skb); | |
6ca8b990 | 690 | return NET_RX_DROP; |
0d66548a OH |
691 | } |
692 | ||
693 | /* | |
694 | * af_can protocol functions | |
695 | */ | |
696 | ||
697 | /** | |
698 | * can_proto_register - register CAN transport protocol | |
699 | * @cp: pointer to CAN protocol structure | |
700 | * | |
701 | * Return: | |
702 | * 0 on success | |
703 | * -EINVAL invalid (out of range) protocol number | |
704 | * -EBUSY protocol already in use | |
705 | * -ENOBUF if proto_register() fails | |
706 | */ | |
707 | int can_proto_register(struct can_proto *cp) | |
708 | { | |
709 | int proto = cp->protocol; | |
710 | int err = 0; | |
711 | ||
712 | if (proto < 0 || proto >= CAN_NPROTO) { | |
713 | printk(KERN_ERR "can: protocol number %d out of range\n", | |
714 | proto); | |
715 | return -EINVAL; | |
716 | } | |
717 | ||
a2fea5f1 UT |
718 | err = proto_register(cp->prot, 0); |
719 | if (err < 0) | |
720 | return err; | |
721 | ||
0d66548a OH |
722 | spin_lock(&proto_tab_lock); |
723 | if (proto_tab[proto]) { | |
724 | printk(KERN_ERR "can: protocol %d already registered\n", | |
725 | proto); | |
726 | err = -EBUSY; | |
a2fea5f1 UT |
727 | } else { |
728 | proto_tab[proto] = cp; | |
729 | ||
730 | /* use generic ioctl function if not defined by module */ | |
731 | if (!cp->ops->ioctl) | |
732 | cp->ops->ioctl = can_ioctl; | |
0d66548a | 733 | } |
a2fea5f1 | 734 | spin_unlock(&proto_tab_lock); |
0d66548a | 735 | |
0d66548a | 736 | if (err < 0) |
a2fea5f1 | 737 | proto_unregister(cp->prot); |
0d66548a OH |
738 | |
739 | return err; | |
740 | } | |
741 | EXPORT_SYMBOL(can_proto_register); | |
742 | ||
743 | /** | |
744 | * can_proto_unregister - unregister CAN transport protocol | |
745 | * @cp: pointer to CAN protocol structure | |
746 | */ | |
747 | void can_proto_unregister(struct can_proto *cp) | |
748 | { | |
749 | int proto = cp->protocol; | |
750 | ||
751 | spin_lock(&proto_tab_lock); | |
752 | if (!proto_tab[proto]) { | |
753 | printk(KERN_ERR "BUG: can: protocol %d is not registered\n", | |
754 | proto); | |
755 | } | |
0d66548a OH |
756 | proto_tab[proto] = NULL; |
757 | spin_unlock(&proto_tab_lock); | |
a2fea5f1 UT |
758 | |
759 | proto_unregister(cp->prot); | |
0d66548a OH |
760 | } |
761 | EXPORT_SYMBOL(can_proto_unregister); | |
762 | ||
763 | /* | |
764 | * af_can notifier to create/remove CAN netdevice specific structs | |
765 | */ | |
766 | static int can_notifier(struct notifier_block *nb, unsigned long msg, | |
767 | void *data) | |
768 | { | |
769 | struct net_device *dev = (struct net_device *)data; | |
770 | struct dev_rcv_lists *d; | |
771 | ||
721499e8 | 772 | if (!net_eq(dev_net(dev), &init_net)) |
0d66548a OH |
773 | return NOTIFY_DONE; |
774 | ||
775 | if (dev->type != ARPHRD_CAN) | |
776 | return NOTIFY_DONE; | |
777 | ||
778 | switch (msg) { | |
779 | ||
780 | case NETDEV_REGISTER: | |
781 | ||
782 | /* | |
783 | * create new dev_rcv_lists for this device | |
784 | * | |
785 | * N.B. zeroing the struct is the correct initialization | |
786 | * for the embedded hlist_head structs. | |
787 | * Another list type, e.g. list_head, would require | |
788 | * explicit initialization. | |
789 | */ | |
790 | ||
791 | d = kzalloc(sizeof(*d), GFP_KERNEL); | |
792 | if (!d) { | |
793 | printk(KERN_ERR | |
794 | "can: allocation of receive list failed\n"); | |
795 | return NOTIFY_DONE; | |
796 | } | |
797 | d->dev = dev; | |
798 | ||
799 | spin_lock(&can_rcvlists_lock); | |
800 | hlist_add_head_rcu(&d->list, &can_rx_dev_list); | |
801 | spin_unlock(&can_rcvlists_lock); | |
802 | ||
803 | break; | |
804 | ||
805 | case NETDEV_UNREGISTER: | |
806 | spin_lock(&can_rcvlists_lock); | |
807 | ||
808 | d = find_dev_rcv_lists(dev); | |
809 | if (d) { | |
810 | if (d->entries) { | |
811 | d->remove_on_zero_entries = 1; | |
812 | d = NULL; | |
813 | } else | |
814 | hlist_del_rcu(&d->list); | |
815 | } else | |
816 | printk(KERN_ERR "can: notifier: receive list not " | |
817 | "found for dev %s\n", dev->name); | |
818 | ||
819 | spin_unlock(&can_rcvlists_lock); | |
820 | ||
821 | if (d) | |
822 | call_rcu(&d->rcu, can_rx_delete_device); | |
823 | ||
824 | break; | |
825 | } | |
826 | ||
827 | return NOTIFY_DONE; | |
828 | } | |
829 | ||
830 | /* | |
831 | * af_can module init/exit functions | |
832 | */ | |
833 | ||
834 | static struct packet_type can_packet __read_mostly = { | |
09640e63 | 835 | .type = cpu_to_be16(ETH_P_CAN), |
0d66548a OH |
836 | .dev = NULL, |
837 | .func = can_rcv, | |
838 | }; | |
839 | ||
ec1b4cf7 | 840 | static const struct net_proto_family can_family_ops = { |
0d66548a OH |
841 | .family = PF_CAN, |
842 | .create = can_create, | |
843 | .owner = THIS_MODULE, | |
844 | }; | |
845 | ||
846 | /* notifier block for netdevice event */ | |
847 | static struct notifier_block can_netdev_notifier __read_mostly = { | |
848 | .notifier_call = can_notifier, | |
849 | }; | |
850 | ||
851 | static __init int can_init(void) | |
852 | { | |
853 | printk(banner); | |
854 | ||
855 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), | |
856 | 0, 0, NULL); | |
857 | if (!rcv_cache) | |
858 | return -ENOMEM; | |
859 | ||
860 | /* | |
861 | * Insert can_rx_alldev_list for reception on all devices. | |
862 | * This struct is zero initialized which is correct for the | |
863 | * embedded hlist heads, the dev pointer, and the entries counter. | |
864 | */ | |
865 | ||
866 | spin_lock(&can_rcvlists_lock); | |
867 | hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list); | |
868 | spin_unlock(&can_rcvlists_lock); | |
869 | ||
870 | if (stats_timer) { | |
871 | /* the statistics are updated every second (timer triggered) */ | |
872 | setup_timer(&can_stattimer, can_stat_update, 0); | |
873 | mod_timer(&can_stattimer, round_jiffies(jiffies + HZ)); | |
874 | } else | |
875 | can_stattimer.function = NULL; | |
876 | ||
877 | can_init_proc(); | |
878 | ||
879 | /* protocol register */ | |
880 | sock_register(&can_family_ops); | |
881 | register_netdevice_notifier(&can_netdev_notifier); | |
882 | dev_add_pack(&can_packet); | |
883 | ||
884 | return 0; | |
885 | } | |
886 | ||
887 | static __exit void can_exit(void) | |
888 | { | |
889 | struct dev_rcv_lists *d; | |
890 | struct hlist_node *n, *next; | |
891 | ||
892 | if (stats_timer) | |
893 | del_timer(&can_stattimer); | |
894 | ||
895 | can_remove_proc(); | |
896 | ||
897 | /* protocol unregister */ | |
898 | dev_remove_pack(&can_packet); | |
899 | unregister_netdevice_notifier(&can_netdev_notifier); | |
900 | sock_unregister(PF_CAN); | |
901 | ||
902 | /* remove can_rx_dev_list */ | |
903 | spin_lock(&can_rcvlists_lock); | |
904 | hlist_del(&can_rx_alldev_list.list); | |
905 | hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) { | |
906 | hlist_del(&d->list); | |
907 | kfree(d); | |
908 | } | |
909 | spin_unlock(&can_rcvlists_lock); | |
910 | ||
382bfeec JDB |
911 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
912 | ||
0d66548a OH |
913 | kmem_cache_destroy(rcv_cache); |
914 | } | |
915 | ||
916 | module_init(can_init); | |
917 | module_exit(can_exit); |