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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 | ||
163 | if (cp->capability >= 0 && !capable(cp->capability)) { | |
164 | err = -EPERM; | |
165 | goto errout; | |
166 | } | |
167 | ||
168 | sock->ops = cp->ops; | |
169 | ||
170 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot); | |
171 | if (!sk) { | |
172 | err = -ENOMEM; | |
173 | goto errout; | |
174 | } | |
175 | ||
176 | sock_init_data(sock, sk); | |
177 | sk->sk_destruct = can_sock_destruct; | |
178 | ||
179 | if (sk->sk_prot->init) | |
180 | err = sk->sk_prot->init(sk); | |
181 | ||
182 | if (err) { | |
183 | /* release sk on errors */ | |
184 | sock_orphan(sk); | |
185 | sock_put(sk); | |
186 | } | |
187 | ||
188 | errout: | |
189 | module_put(cp->prot->owner); | |
190 | return err; | |
191 | } | |
192 | ||
193 | /* | |
194 | * af_can tx path | |
195 | */ | |
196 | ||
197 | /** | |
198 | * can_send - transmit a CAN frame (optional with local loopback) | |
199 | * @skb: pointer to socket buffer with CAN frame in data section | |
200 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
201 | * | |
481a8199 OH |
202 | * Due to the loopback this routine must not be called from hardirq context. |
203 | * | |
0d66548a OH |
204 | * Return: |
205 | * 0 on success | |
206 | * -ENETDOWN when the selected interface is down | |
207 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
208 | * -ENOMEM when local loopback failed at calling skb_clone() | |
209 | * -EPERM when trying to send on a non-CAN interface | |
7f2d38eb | 210 | * -EINVAL when the skb->data does not contain a valid CAN frame |
0d66548a OH |
211 | */ |
212 | int can_send(struct sk_buff *skb, int loop) | |
213 | { | |
c2ab7ac2 | 214 | struct sk_buff *newskb = NULL; |
7f2d38eb | 215 | struct can_frame *cf = (struct can_frame *)skb->data; |
0d66548a OH |
216 | int err; |
217 | ||
7f2d38eb OH |
218 | if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) { |
219 | kfree_skb(skb); | |
220 | return -EINVAL; | |
221 | } | |
222 | ||
0d66548a OH |
223 | if (skb->dev->type != ARPHRD_CAN) { |
224 | kfree_skb(skb); | |
225 | return -EPERM; | |
226 | } | |
227 | ||
228 | if (!(skb->dev->flags & IFF_UP)) { | |
229 | kfree_skb(skb); | |
230 | return -ENETDOWN; | |
231 | } | |
232 | ||
233 | skb->protocol = htons(ETH_P_CAN); | |
234 | skb_reset_network_header(skb); | |
235 | skb_reset_transport_header(skb); | |
236 | ||
237 | if (loop) { | |
238 | /* local loopback of sent CAN frames */ | |
239 | ||
240 | /* indication for the CAN driver: do loopback */ | |
241 | skb->pkt_type = PACKET_LOOPBACK; | |
242 | ||
243 | /* | |
244 | * The reference to the originating sock may be required | |
245 | * by the receiving socket to check whether the frame is | |
246 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS | |
247 | * Therefore we have to ensure that skb->sk remains the | |
248 | * reference to the originating sock by restoring skb->sk | |
249 | * after each skb_clone() or skb_orphan() usage. | |
250 | */ | |
251 | ||
252 | if (!(skb->dev->flags & IFF_ECHO)) { | |
253 | /* | |
254 | * If the interface is not capable to do loopback | |
255 | * itself, we do it here. | |
256 | */ | |
c2ab7ac2 | 257 | newskb = skb_clone(skb, GFP_ATOMIC); |
0d66548a OH |
258 | if (!newskb) { |
259 | kfree_skb(skb); | |
260 | return -ENOMEM; | |
261 | } | |
262 | ||
263 | newskb->sk = skb->sk; | |
264 | newskb->ip_summed = CHECKSUM_UNNECESSARY; | |
265 | newskb->pkt_type = PACKET_BROADCAST; | |
0d66548a OH |
266 | } |
267 | } else { | |
268 | /* indication for the CAN driver: no loopback required */ | |
269 | skb->pkt_type = PACKET_HOST; | |
270 | } | |
271 | ||
272 | /* send to netdevice */ | |
273 | err = dev_queue_xmit(skb); | |
274 | if (err > 0) | |
275 | err = net_xmit_errno(err); | |
276 | ||
c2ab7ac2 | 277 | if (err) { |
ce030edf | 278 | kfree_skb(newskb); |
c2ab7ac2 OH |
279 | return err; |
280 | } | |
281 | ||
282 | if (newskb) | |
481a8199 | 283 | netif_rx_ni(newskb); |
c2ab7ac2 | 284 | |
0d66548a OH |
285 | /* update statistics */ |
286 | can_stats.tx_frames++; | |
287 | can_stats.tx_frames_delta++; | |
288 | ||
c2ab7ac2 | 289 | return 0; |
0d66548a OH |
290 | } |
291 | EXPORT_SYMBOL(can_send); | |
292 | ||
293 | /* | |
294 | * af_can rx path | |
295 | */ | |
296 | ||
297 | static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) | |
298 | { | |
299 | struct dev_rcv_lists *d = NULL; | |
300 | struct hlist_node *n; | |
301 | ||
302 | /* | |
303 | * find receive list for this device | |
304 | * | |
305 | * The hlist_for_each_entry*() macros curse through the list | |
306 | * using the pointer variable n and set d to the containing | |
307 | * struct in each list iteration. Therefore, after list | |
308 | * iteration, d is unmodified when the list is empty, and it | |
309 | * points to last list element, when the list is non-empty | |
310 | * but no match in the loop body is found. I.e. d is *not* | |
311 | * NULL when no match is found. We can, however, use the | |
312 | * cursor variable n to decide if a match was found. | |
313 | */ | |
314 | ||
315 | hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) { | |
316 | if (d->dev == dev) | |
317 | break; | |
318 | } | |
319 | ||
320 | return n ? d : NULL; | |
321 | } | |
322 | ||
d253eee2 OH |
323 | /** |
324 | * find_rcv_list - determine optimal filterlist inside device filter struct | |
325 | * @can_id: pointer to CAN identifier of a given can_filter | |
326 | * @mask: pointer to CAN mask of a given can_filter | |
327 | * @d: pointer to the device filter struct | |
328 | * | |
329 | * Description: | |
330 | * Returns the optimal filterlist to reduce the filter handling in the | |
331 | * receive path. This function is called by service functions that need | |
332 | * to register or unregister a can_filter in the filter lists. | |
333 | * | |
334 | * A filter matches in general, when | |
335 | * | |
336 | * <received_can_id> & mask == can_id & mask | |
337 | * | |
338 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe | |
339 | * relevant bits for the filter. | |
340 | * | |
341 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
342 | * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames | |
343 | * there is a special filterlist and a special rx path filter handling. | |
344 | * | |
345 | * Return: | |
346 | * Pointer to optimal filterlist for the given can_id/mask pair. | |
347 | * Constistency checked mask. | |
348 | * Reduced can_id to have a preprocessed filter compare value. | |
349 | */ | |
0d66548a OH |
350 | static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, |
351 | struct dev_rcv_lists *d) | |
352 | { | |
353 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
354 | ||
d253eee2 | 355 | /* filter for error frames in extra filterlist */ |
0d66548a | 356 | if (*mask & CAN_ERR_FLAG) { |
d253eee2 | 357 | /* clear CAN_ERR_FLAG in filter entry */ |
0d66548a OH |
358 | *mask &= CAN_ERR_MASK; |
359 | return &d->rx[RX_ERR]; | |
360 | } | |
361 | ||
d253eee2 OH |
362 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
363 | ||
364 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) | |
365 | ||
366 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ | |
367 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) | |
368 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); | |
0d66548a OH |
369 | |
370 | /* reduce condition testing at receive time */ | |
371 | *can_id &= *mask; | |
372 | ||
373 | /* inverse can_id/can_mask filter */ | |
374 | if (inv) | |
375 | return &d->rx[RX_INV]; | |
376 | ||
377 | /* mask == 0 => no condition testing at receive time */ | |
378 | if (!(*mask)) | |
379 | return &d->rx[RX_ALL]; | |
380 | ||
d253eee2 OH |
381 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
382 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) | |
383 | && !(*can_id & CAN_RTR_FLAG)) { | |
384 | ||
385 | if (*can_id & CAN_EFF_FLAG) { | |
386 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) { | |
387 | /* RFC: a future use-case for hash-tables? */ | |
388 | return &d->rx[RX_EFF]; | |
389 | } | |
390 | } else { | |
391 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) | |
392 | return &d->rx_sff[*can_id]; | |
0d66548a | 393 | } |
0d66548a OH |
394 | } |
395 | ||
396 | /* default: filter via can_id/can_mask */ | |
397 | return &d->rx[RX_FIL]; | |
398 | } | |
399 | ||
400 | /** | |
401 | * can_rx_register - subscribe CAN frames from a specific interface | |
402 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
403 | * @can_id: CAN identifier (see description) | |
404 | * @mask: CAN mask (see description) | |
405 | * @func: callback function on filter match | |
406 | * @data: returned parameter for callback function | |
407 | * @ident: string for calling module indentification | |
408 | * | |
409 | * Description: | |
410 | * Invokes the callback function with the received sk_buff and the given | |
411 | * parameter 'data' on a matching receive filter. A filter matches, when | |
412 | * | |
413 | * <received_can_id> & mask == can_id & mask | |
414 | * | |
415 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
416 | * filter for error frames (CAN_ERR_FLAG bit set in mask). | |
417 | * | |
1fa17d4b OH |
418 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
419 | * the callback function is running. The callback function must *not* free | |
420 | * the given sk_buff while processing it's task. When the given sk_buff is | |
421 | * needed after the end of the callback function it must be cloned inside | |
422 | * the callback function with skb_clone(). | |
423 | * | |
0d66548a OH |
424 | * Return: |
425 | * 0 on success | |
426 | * -ENOMEM on missing cache mem to create subscription entry | |
427 | * -ENODEV unknown device | |
428 | */ | |
429 | int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask, | |
430 | void (*func)(struct sk_buff *, void *), void *data, | |
431 | char *ident) | |
432 | { | |
433 | struct receiver *r; | |
434 | struct hlist_head *rl; | |
435 | struct dev_rcv_lists *d; | |
436 | int err = 0; | |
437 | ||
438 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
439 | ||
440 | r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); | |
441 | if (!r) | |
442 | return -ENOMEM; | |
443 | ||
444 | spin_lock(&can_rcvlists_lock); | |
445 | ||
446 | d = find_dev_rcv_lists(dev); | |
447 | if (d) { | |
448 | rl = find_rcv_list(&can_id, &mask, d); | |
449 | ||
450 | r->can_id = can_id; | |
451 | r->mask = mask; | |
452 | r->matches = 0; | |
453 | r->func = func; | |
454 | r->data = data; | |
455 | r->ident = ident; | |
456 | ||
457 | hlist_add_head_rcu(&r->list, rl); | |
458 | d->entries++; | |
459 | ||
460 | can_pstats.rcv_entries++; | |
461 | if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) | |
462 | can_pstats.rcv_entries_max = can_pstats.rcv_entries; | |
463 | } else { | |
464 | kmem_cache_free(rcv_cache, r); | |
465 | err = -ENODEV; | |
466 | } | |
467 | ||
468 | spin_unlock(&can_rcvlists_lock); | |
469 | ||
470 | return err; | |
471 | } | |
472 | EXPORT_SYMBOL(can_rx_register); | |
473 | ||
474 | /* | |
475 | * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal | |
476 | */ | |
477 | static void can_rx_delete_device(struct rcu_head *rp) | |
478 | { | |
479 | struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu); | |
480 | ||
481 | kfree(d); | |
482 | } | |
483 | ||
484 | /* | |
485 | * can_rx_delete_receiver - rcu callback for single receiver entry removal | |
486 | */ | |
487 | static void can_rx_delete_receiver(struct rcu_head *rp) | |
488 | { | |
489 | struct receiver *r = container_of(rp, struct receiver, rcu); | |
490 | ||
491 | kmem_cache_free(rcv_cache, r); | |
492 | } | |
493 | ||
494 | /** | |
495 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
496 | * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list) | |
497 | * @can_id: CAN identifier | |
498 | * @mask: CAN mask | |
499 | * @func: callback function on filter match | |
500 | * @data: returned parameter for callback function | |
501 | * | |
502 | * Description: | |
503 | * Removes subscription entry depending on given (subscription) values. | |
504 | */ | |
505 | void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, | |
506 | void (*func)(struct sk_buff *, void *), void *data) | |
507 | { | |
508 | struct receiver *r = NULL; | |
509 | struct hlist_head *rl; | |
510 | struct hlist_node *next; | |
511 | struct dev_rcv_lists *d; | |
512 | ||
513 | spin_lock(&can_rcvlists_lock); | |
514 | ||
515 | d = find_dev_rcv_lists(dev); | |
516 | if (!d) { | |
517 | printk(KERN_ERR "BUG: receive list not found for " | |
518 | "dev %s, id %03X, mask %03X\n", | |
519 | DNAME(dev), can_id, mask); | |
520 | goto out; | |
521 | } | |
522 | ||
523 | rl = find_rcv_list(&can_id, &mask, d); | |
524 | ||
525 | /* | |
526 | * Search the receiver list for the item to delete. This should | |
527 | * exist, since no receiver may be unregistered that hasn't | |
528 | * been registered before. | |
529 | */ | |
530 | ||
531 | hlist_for_each_entry_rcu(r, next, rl, list) { | |
532 | if (r->can_id == can_id && r->mask == mask | |
533 | && r->func == func && r->data == data) | |
534 | break; | |
535 | } | |
536 | ||
537 | /* | |
538 | * Check for bugs in CAN protocol implementations: | |
539 | * If no matching list item was found, the list cursor variable next | |
540 | * will be NULL, while r will point to the last item of the list. | |
541 | */ | |
542 | ||
543 | if (!next) { | |
544 | printk(KERN_ERR "BUG: receive list entry not found for " | |
545 | "dev %s, id %03X, mask %03X\n", | |
546 | DNAME(dev), can_id, mask); | |
547 | r = NULL; | |
548 | d = NULL; | |
549 | goto out; | |
550 | } | |
551 | ||
552 | hlist_del_rcu(&r->list); | |
553 | d->entries--; | |
554 | ||
555 | if (can_pstats.rcv_entries > 0) | |
556 | can_pstats.rcv_entries--; | |
557 | ||
558 | /* remove device structure requested by NETDEV_UNREGISTER */ | |
559 | if (d->remove_on_zero_entries && !d->entries) | |
560 | hlist_del_rcu(&d->list); | |
561 | else | |
562 | d = NULL; | |
563 | ||
564 | out: | |
565 | spin_unlock(&can_rcvlists_lock); | |
566 | ||
567 | /* schedule the receiver item for deletion */ | |
568 | if (r) | |
569 | call_rcu(&r->rcu, can_rx_delete_receiver); | |
570 | ||
571 | /* schedule the device structure for deletion */ | |
572 | if (d) | |
573 | call_rcu(&d->rcu, can_rx_delete_device); | |
574 | } | |
575 | EXPORT_SYMBOL(can_rx_unregister); | |
576 | ||
577 | static inline void deliver(struct sk_buff *skb, struct receiver *r) | |
578 | { | |
1fa17d4b OH |
579 | r->func(skb, r->data); |
580 | r->matches++; | |
0d66548a OH |
581 | } |
582 | ||
583 | static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) | |
584 | { | |
585 | struct receiver *r; | |
586 | struct hlist_node *n; | |
587 | int matches = 0; | |
588 | struct can_frame *cf = (struct can_frame *)skb->data; | |
589 | canid_t can_id = cf->can_id; | |
590 | ||
591 | if (d->entries == 0) | |
592 | return 0; | |
593 | ||
594 | if (can_id & CAN_ERR_FLAG) { | |
595 | /* check for error frame entries only */ | |
596 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) { | |
597 | if (can_id & r->mask) { | |
598 | deliver(skb, r); | |
599 | matches++; | |
600 | } | |
601 | } | |
602 | return matches; | |
603 | } | |
604 | ||
605 | /* check for unfiltered entries */ | |
606 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) { | |
607 | deliver(skb, r); | |
608 | matches++; | |
609 | } | |
610 | ||
611 | /* check for can_id/mask entries */ | |
612 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) { | |
613 | if ((can_id & r->mask) == r->can_id) { | |
614 | deliver(skb, r); | |
615 | matches++; | |
616 | } | |
617 | } | |
618 | ||
619 | /* check for inverted can_id/mask entries */ | |
620 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) { | |
621 | if ((can_id & r->mask) != r->can_id) { | |
622 | deliver(skb, r); | |
623 | matches++; | |
624 | } | |
625 | } | |
626 | ||
f706644d OH |
627 | /* check filterlists for single non-RTR can_ids */ |
628 | if (can_id & CAN_RTR_FLAG) | |
629 | return matches; | |
630 | ||
0d66548a OH |
631 | if (can_id & CAN_EFF_FLAG) { |
632 | hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) { | |
633 | if (r->can_id == can_id) { | |
634 | deliver(skb, r); | |
635 | matches++; | |
636 | } | |
637 | } | |
638 | } else { | |
639 | can_id &= CAN_SFF_MASK; | |
640 | hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) { | |
641 | deliver(skb, r); | |
642 | matches++; | |
643 | } | |
644 | } | |
645 | ||
646 | return matches; | |
647 | } | |
648 | ||
649 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
650 | struct packet_type *pt, struct net_device *orig_dev) | |
651 | { | |
652 | struct dev_rcv_lists *d; | |
7f2d38eb | 653 | struct can_frame *cf = (struct can_frame *)skb->data; |
0d66548a OH |
654 | int matches; |
655 | ||
1758c094 OH |
656 | if (!net_eq(dev_net(dev), &init_net)) |
657 | goto drop; | |
0d66548a | 658 | |
1758c094 OH |
659 | if (WARN_ONCE(dev->type != ARPHRD_CAN || |
660 | skb->len != sizeof(struct can_frame) || | |
661 | cf->can_dlc > 8, | |
662 | "PF_CAN: dropped non conform skbuf: " | |
663 | "dev type %d, len %d, can_dlc %d\n", | |
664 | dev->type, skb->len, cf->can_dlc)) | |
665 | goto drop; | |
7f2d38eb | 666 | |
0d66548a OH |
667 | /* update statistics */ |
668 | can_stats.rx_frames++; | |
669 | can_stats.rx_frames_delta++; | |
670 | ||
671 | rcu_read_lock(); | |
672 | ||
673 | /* deliver the packet to sockets listening on all devices */ | |
674 | matches = can_rcv_filter(&can_rx_alldev_list, skb); | |
675 | ||
676 | /* find receive list for this device */ | |
677 | d = find_dev_rcv_lists(dev); | |
678 | if (d) | |
679 | matches += can_rcv_filter(d, skb); | |
680 | ||
681 | rcu_read_unlock(); | |
682 | ||
62bcaa13 OH |
683 | /* consume the skbuff allocated by the netdevice driver */ |
684 | consume_skb(skb); | |
0d66548a OH |
685 | |
686 | if (matches > 0) { | |
687 | can_stats.matches++; | |
688 | can_stats.matches_delta++; | |
689 | } | |
690 | ||
6ca8b990 | 691 | return NET_RX_SUCCESS; |
1758c094 OH |
692 | |
693 | drop: | |
694 | kfree_skb(skb); | |
6ca8b990 | 695 | return NET_RX_DROP; |
0d66548a OH |
696 | } |
697 | ||
698 | /* | |
699 | * af_can protocol functions | |
700 | */ | |
701 | ||
702 | /** | |
703 | * can_proto_register - register CAN transport protocol | |
704 | * @cp: pointer to CAN protocol structure | |
705 | * | |
706 | * Return: | |
707 | * 0 on success | |
708 | * -EINVAL invalid (out of range) protocol number | |
709 | * -EBUSY protocol already in use | |
710 | * -ENOBUF if proto_register() fails | |
711 | */ | |
712 | int can_proto_register(struct can_proto *cp) | |
713 | { | |
714 | int proto = cp->protocol; | |
715 | int err = 0; | |
716 | ||
717 | if (proto < 0 || proto >= CAN_NPROTO) { | |
718 | printk(KERN_ERR "can: protocol number %d out of range\n", | |
719 | proto); | |
720 | return -EINVAL; | |
721 | } | |
722 | ||
a2fea5f1 UT |
723 | err = proto_register(cp->prot, 0); |
724 | if (err < 0) | |
725 | return err; | |
726 | ||
0d66548a OH |
727 | spin_lock(&proto_tab_lock); |
728 | if (proto_tab[proto]) { | |
729 | printk(KERN_ERR "can: protocol %d already registered\n", | |
730 | proto); | |
731 | err = -EBUSY; | |
a2fea5f1 UT |
732 | } else { |
733 | proto_tab[proto] = cp; | |
734 | ||
735 | /* use generic ioctl function if not defined by module */ | |
736 | if (!cp->ops->ioctl) | |
737 | cp->ops->ioctl = can_ioctl; | |
0d66548a | 738 | } |
a2fea5f1 | 739 | spin_unlock(&proto_tab_lock); |
0d66548a | 740 | |
0d66548a | 741 | if (err < 0) |
a2fea5f1 | 742 | proto_unregister(cp->prot); |
0d66548a OH |
743 | |
744 | return err; | |
745 | } | |
746 | EXPORT_SYMBOL(can_proto_register); | |
747 | ||
748 | /** | |
749 | * can_proto_unregister - unregister CAN transport protocol | |
750 | * @cp: pointer to CAN protocol structure | |
751 | */ | |
752 | void can_proto_unregister(struct can_proto *cp) | |
753 | { | |
754 | int proto = cp->protocol; | |
755 | ||
756 | spin_lock(&proto_tab_lock); | |
757 | if (!proto_tab[proto]) { | |
758 | printk(KERN_ERR "BUG: can: protocol %d is not registered\n", | |
759 | proto); | |
760 | } | |
0d66548a OH |
761 | proto_tab[proto] = NULL; |
762 | spin_unlock(&proto_tab_lock); | |
a2fea5f1 UT |
763 | |
764 | proto_unregister(cp->prot); | |
0d66548a OH |
765 | } |
766 | EXPORT_SYMBOL(can_proto_unregister); | |
767 | ||
768 | /* | |
769 | * af_can notifier to create/remove CAN netdevice specific structs | |
770 | */ | |
771 | static int can_notifier(struct notifier_block *nb, unsigned long msg, | |
772 | void *data) | |
773 | { | |
774 | struct net_device *dev = (struct net_device *)data; | |
775 | struct dev_rcv_lists *d; | |
776 | ||
721499e8 | 777 | if (!net_eq(dev_net(dev), &init_net)) |
0d66548a OH |
778 | return NOTIFY_DONE; |
779 | ||
780 | if (dev->type != ARPHRD_CAN) | |
781 | return NOTIFY_DONE; | |
782 | ||
783 | switch (msg) { | |
784 | ||
785 | case NETDEV_REGISTER: | |
786 | ||
787 | /* | |
788 | * create new dev_rcv_lists for this device | |
789 | * | |
790 | * N.B. zeroing the struct is the correct initialization | |
791 | * for the embedded hlist_head structs. | |
792 | * Another list type, e.g. list_head, would require | |
793 | * explicit initialization. | |
794 | */ | |
795 | ||
796 | d = kzalloc(sizeof(*d), GFP_KERNEL); | |
797 | if (!d) { | |
798 | printk(KERN_ERR | |
799 | "can: allocation of receive list failed\n"); | |
800 | return NOTIFY_DONE; | |
801 | } | |
802 | d->dev = dev; | |
803 | ||
804 | spin_lock(&can_rcvlists_lock); | |
805 | hlist_add_head_rcu(&d->list, &can_rx_dev_list); | |
806 | spin_unlock(&can_rcvlists_lock); | |
807 | ||
808 | break; | |
809 | ||
810 | case NETDEV_UNREGISTER: | |
811 | spin_lock(&can_rcvlists_lock); | |
812 | ||
813 | d = find_dev_rcv_lists(dev); | |
814 | if (d) { | |
815 | if (d->entries) { | |
816 | d->remove_on_zero_entries = 1; | |
817 | d = NULL; | |
818 | } else | |
819 | hlist_del_rcu(&d->list); | |
820 | } else | |
821 | printk(KERN_ERR "can: notifier: receive list not " | |
822 | "found for dev %s\n", dev->name); | |
823 | ||
824 | spin_unlock(&can_rcvlists_lock); | |
825 | ||
826 | if (d) | |
827 | call_rcu(&d->rcu, can_rx_delete_device); | |
828 | ||
829 | break; | |
830 | } | |
831 | ||
832 | return NOTIFY_DONE; | |
833 | } | |
834 | ||
835 | /* | |
836 | * af_can module init/exit functions | |
837 | */ | |
838 | ||
839 | static struct packet_type can_packet __read_mostly = { | |
09640e63 | 840 | .type = cpu_to_be16(ETH_P_CAN), |
0d66548a OH |
841 | .dev = NULL, |
842 | .func = can_rcv, | |
843 | }; | |
844 | ||
845 | static struct net_proto_family can_family_ops __read_mostly = { | |
846 | .family = PF_CAN, | |
847 | .create = can_create, | |
848 | .owner = THIS_MODULE, | |
849 | }; | |
850 | ||
851 | /* notifier block for netdevice event */ | |
852 | static struct notifier_block can_netdev_notifier __read_mostly = { | |
853 | .notifier_call = can_notifier, | |
854 | }; | |
855 | ||
856 | static __init int can_init(void) | |
857 | { | |
858 | printk(banner); | |
859 | ||
860 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), | |
861 | 0, 0, NULL); | |
862 | if (!rcv_cache) | |
863 | return -ENOMEM; | |
864 | ||
865 | /* | |
866 | * Insert can_rx_alldev_list for reception on all devices. | |
867 | * This struct is zero initialized which is correct for the | |
868 | * embedded hlist heads, the dev pointer, and the entries counter. | |
869 | */ | |
870 | ||
871 | spin_lock(&can_rcvlists_lock); | |
872 | hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list); | |
873 | spin_unlock(&can_rcvlists_lock); | |
874 | ||
875 | if (stats_timer) { | |
876 | /* the statistics are updated every second (timer triggered) */ | |
877 | setup_timer(&can_stattimer, can_stat_update, 0); | |
878 | mod_timer(&can_stattimer, round_jiffies(jiffies + HZ)); | |
879 | } else | |
880 | can_stattimer.function = NULL; | |
881 | ||
882 | can_init_proc(); | |
883 | ||
884 | /* protocol register */ | |
885 | sock_register(&can_family_ops); | |
886 | register_netdevice_notifier(&can_netdev_notifier); | |
887 | dev_add_pack(&can_packet); | |
888 | ||
889 | return 0; | |
890 | } | |
891 | ||
892 | static __exit void can_exit(void) | |
893 | { | |
894 | struct dev_rcv_lists *d; | |
895 | struct hlist_node *n, *next; | |
896 | ||
897 | if (stats_timer) | |
898 | del_timer(&can_stattimer); | |
899 | ||
900 | can_remove_proc(); | |
901 | ||
902 | /* protocol unregister */ | |
903 | dev_remove_pack(&can_packet); | |
904 | unregister_netdevice_notifier(&can_netdev_notifier); | |
905 | sock_unregister(PF_CAN); | |
906 | ||
907 | /* remove can_rx_dev_list */ | |
908 | spin_lock(&can_rcvlists_lock); | |
909 | hlist_del(&can_rx_alldev_list.list); | |
910 | hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) { | |
911 | hlist_del(&d->list); | |
912 | kfree(d); | |
913 | } | |
914 | spin_unlock(&can_rcvlists_lock); | |
915 | ||
382bfeec JDB |
916 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
917 | ||
0d66548a OH |
918 | kmem_cache_destroy(rcv_cache); |
919 | } | |
920 | ||
921 | module_init(can_init); | |
922 | module_exit(can_exit); |