Commit | Line | Data |
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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 | * | |
0d66548a OH |
41 | */ |
42 | ||
43 | #include <linux/module.h> | |
7c941636 | 44 | #include <linux/stddef.h> |
0d66548a OH |
45 | #include <linux/init.h> |
46 | #include <linux/kmod.h> | |
47 | #include <linux/slab.h> | |
48 | #include <linux/list.h> | |
49 | #include <linux/spinlock.h> | |
50 | #include <linux/rcupdate.h> | |
51 | #include <linux/uaccess.h> | |
52 | #include <linux/net.h> | |
53 | #include <linux/netdevice.h> | |
54 | #include <linux/socket.h> | |
55 | #include <linux/if_ether.h> | |
56 | #include <linux/if_arp.h> | |
57 | #include <linux/skbuff.h> | |
58 | #include <linux/can.h> | |
59 | #include <linux/can/core.h> | |
0ae89beb | 60 | #include <linux/can/skb.h> |
d751e623 | 61 | #include <linux/ratelimit.h> |
0d66548a OH |
62 | #include <net/net_namespace.h> |
63 | #include <net/sock.h> | |
64 | ||
65 | #include "af_can.h" | |
66 | ||
6299b669 | 67 | static __initconst const char banner[] = KERN_INFO |
0d66548a OH |
68 | "can: controller area network core (" CAN_VERSION_STRING ")\n"; |
69 | ||
70 | MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); | |
71 | MODULE_LICENSE("Dual BSD/GPL"); | |
72 | MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, " | |
73 | "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); | |
74 | ||
75 | MODULE_ALIAS_NETPROTO(PF_CAN); | |
76 | ||
77 | static int stats_timer __read_mostly = 1; | |
78 | module_param(stats_timer, int, S_IRUGO); | |
79 | MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); | |
80 | ||
20dd3850 OH |
81 | /* receive filters subscribed for 'all' CAN devices */ |
82 | struct dev_rcv_lists can_rx_alldev_list; | |
0d66548a OH |
83 | static DEFINE_SPINLOCK(can_rcvlists_lock); |
84 | ||
85 | static struct kmem_cache *rcv_cache __read_mostly; | |
86 | ||
87 | /* table of registered CAN protocols */ | |
1650629d | 88 | static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly; |
1ca050d9 | 89 | static DEFINE_MUTEX(proto_tab_lock); |
0d66548a OH |
90 | |
91 | struct timer_list can_stattimer; /* timer for statistics update */ | |
92 | struct s_stats can_stats; /* packet statistics */ | |
93 | struct s_pstats can_pstats; /* receive list statistics */ | |
94 | ||
95 | /* | |
96 | * af_can socket functions | |
97 | */ | |
98 | ||
53914b67 | 99 | int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
0d66548a OH |
100 | { |
101 | struct sock *sk = sock->sk; | |
102 | ||
103 | switch (cmd) { | |
104 | ||
105 | case SIOCGSTAMP: | |
106 | return sock_get_timestamp(sk, (struct timeval __user *)arg); | |
107 | ||
108 | default: | |
109 | return -ENOIOCTLCMD; | |
110 | } | |
111 | } | |
53914b67 | 112 | EXPORT_SYMBOL(can_ioctl); |
0d66548a OH |
113 | |
114 | static void can_sock_destruct(struct sock *sk) | |
115 | { | |
116 | skb_queue_purge(&sk->sk_receive_queue); | |
117 | } | |
118 | ||
c8d55a9d | 119 | static const struct can_proto *can_get_proto(int protocol) |
1ca050d9 | 120 | { |
1650629d | 121 | const struct can_proto *cp; |
1ca050d9 OH |
122 | |
123 | rcu_read_lock(); | |
124 | cp = rcu_dereference(proto_tab[protocol]); | |
125 | if (cp && !try_module_get(cp->prot->owner)) | |
126 | cp = NULL; | |
127 | rcu_read_unlock(); | |
128 | ||
129 | return cp; | |
130 | } | |
131 | ||
c8d55a9d KVD |
132 | static inline void can_put_proto(const struct can_proto *cp) |
133 | { | |
134 | module_put(cp->prot->owner); | |
135 | } | |
136 | ||
3f378b68 EP |
137 | static int can_create(struct net *net, struct socket *sock, int protocol, |
138 | int kern) | |
0d66548a OH |
139 | { |
140 | struct sock *sk; | |
1650629d | 141 | const struct can_proto *cp; |
0d66548a OH |
142 | int err = 0; |
143 | ||
144 | sock->state = SS_UNCONNECTED; | |
145 | ||
146 | if (protocol < 0 || protocol >= CAN_NPROTO) | |
147 | return -EINVAL; | |
148 | ||
09ad9bc7 | 149 | if (!net_eq(net, &init_net)) |
0d66548a OH |
150 | return -EAFNOSUPPORT; |
151 | ||
c8d55a9d | 152 | cp = can_get_proto(protocol); |
1ca050d9 | 153 | |
95a5afca | 154 | #ifdef CONFIG_MODULES |
1ca050d9 OH |
155 | if (!cp) { |
156 | /* try to load protocol module if kernel is modular */ | |
157 | ||
5423dd67 | 158 | err = request_module("can-proto-%d", protocol); |
0d66548a OH |
159 | |
160 | /* | |
161 | * In case of error we only print a message but don't | |
162 | * return the error code immediately. Below we will | |
163 | * return -EPROTONOSUPPORT | |
164 | */ | |
d751e623 MZ |
165 | if (err) |
166 | printk_ratelimited(KERN_ERR "can: request_module " | |
5423dd67 | 167 | "(can-proto-%d) failed.\n", protocol); |
1ca050d9 | 168 | |
c8d55a9d | 169 | cp = can_get_proto(protocol); |
0d66548a | 170 | } |
5423dd67 | 171 | #endif |
0d66548a | 172 | |
0d66548a OH |
173 | /* check for available protocol and correct usage */ |
174 | ||
175 | if (!cp) | |
176 | return -EPROTONOSUPPORT; | |
177 | ||
178 | if (cp->type != sock->type) { | |
1ca050d9 | 179 | err = -EPROTOTYPE; |
0d66548a OH |
180 | goto errout; |
181 | } | |
182 | ||
0d66548a OH |
183 | sock->ops = cp->ops; |
184 | ||
185 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot); | |
186 | if (!sk) { | |
187 | err = -ENOMEM; | |
188 | goto errout; | |
189 | } | |
190 | ||
191 | sock_init_data(sock, sk); | |
192 | sk->sk_destruct = can_sock_destruct; | |
193 | ||
194 | if (sk->sk_prot->init) | |
195 | err = sk->sk_prot->init(sk); | |
196 | ||
197 | if (err) { | |
198 | /* release sk on errors */ | |
199 | sock_orphan(sk); | |
200 | sock_put(sk); | |
201 | } | |
202 | ||
203 | errout: | |
c8d55a9d | 204 | can_put_proto(cp); |
0d66548a OH |
205 | return err; |
206 | } | |
207 | ||
208 | /* | |
209 | * af_can tx path | |
210 | */ | |
211 | ||
212 | /** | |
213 | * can_send - transmit a CAN frame (optional with local loopback) | |
214 | * @skb: pointer to socket buffer with CAN frame in data section | |
215 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
216 | * | |
481a8199 OH |
217 | * Due to the loopback this routine must not be called from hardirq context. |
218 | * | |
0d66548a OH |
219 | * Return: |
220 | * 0 on success | |
221 | * -ENETDOWN when the selected interface is down | |
222 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
223 | * -ENOMEM when local loopback failed at calling skb_clone() | |
224 | * -EPERM when trying to send on a non-CAN interface | |
8b01939f | 225 | * -EMSGSIZE CAN frame size is bigger than CAN interface MTU |
7f2d38eb | 226 | * -EINVAL when the skb->data does not contain a valid CAN frame |
0d66548a OH |
227 | */ |
228 | int can_send(struct sk_buff *skb, int loop) | |
229 | { | |
c2ab7ac2 | 230 | struct sk_buff *newskb = NULL; |
8b01939f OH |
231 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; |
232 | int err = -EINVAL; | |
233 | ||
234 | if (skb->len == CAN_MTU) { | |
235 | skb->protocol = htons(ETH_P_CAN); | |
236 | if (unlikely(cfd->len > CAN_MAX_DLEN)) | |
237 | goto inval_skb; | |
238 | } else if (skb->len == CANFD_MTU) { | |
239 | skb->protocol = htons(ETH_P_CANFD); | |
240 | if (unlikely(cfd->len > CANFD_MAX_DLEN)) | |
241 | goto inval_skb; | |
242 | } else | |
243 | goto inval_skb; | |
0d66548a | 244 | |
8b01939f OH |
245 | /* |
246 | * Make sure the CAN frame can pass the selected CAN netdevice. | |
247 | * As structs can_frame and canfd_frame are similar, we can provide | |
248 | * CAN FD frames to legacy CAN drivers as long as the length is <= 8 | |
249 | */ | |
250 | if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) { | |
251 | err = -EMSGSIZE; | |
252 | goto inval_skb; | |
7f2d38eb OH |
253 | } |
254 | ||
8b01939f OH |
255 | if (unlikely(skb->dev->type != ARPHRD_CAN)) { |
256 | err = -EPERM; | |
257 | goto inval_skb; | |
0d66548a OH |
258 | } |
259 | ||
8b01939f OH |
260 | if (unlikely(!(skb->dev->flags & IFF_UP))) { |
261 | err = -ENETDOWN; | |
262 | goto inval_skb; | |
0d66548a OH |
263 | } |
264 | ||
0d66548a OH |
265 | skb_reset_network_header(skb); |
266 | skb_reset_transport_header(skb); | |
267 | ||
268 | if (loop) { | |
269 | /* local loopback of sent CAN frames */ | |
270 | ||
271 | /* indication for the CAN driver: do loopback */ | |
272 | skb->pkt_type = PACKET_LOOPBACK; | |
273 | ||
274 | /* | |
275 | * The reference to the originating sock may be required | |
276 | * by the receiving socket to check whether the frame is | |
277 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS | |
278 | * Therefore we have to ensure that skb->sk remains the | |
279 | * reference to the originating sock by restoring skb->sk | |
280 | * after each skb_clone() or skb_orphan() usage. | |
281 | */ | |
282 | ||
283 | if (!(skb->dev->flags & IFF_ECHO)) { | |
284 | /* | |
285 | * If the interface is not capable to do loopback | |
286 | * itself, we do it here. | |
287 | */ | |
c2ab7ac2 | 288 | newskb = skb_clone(skb, GFP_ATOMIC); |
0d66548a OH |
289 | if (!newskb) { |
290 | kfree_skb(skb); | |
291 | return -ENOMEM; | |
292 | } | |
293 | ||
0ae89beb | 294 | can_skb_set_owner(newskb, skb->sk); |
0d66548a OH |
295 | newskb->ip_summed = CHECKSUM_UNNECESSARY; |
296 | newskb->pkt_type = PACKET_BROADCAST; | |
0d66548a OH |
297 | } |
298 | } else { | |
299 | /* indication for the CAN driver: no loopback required */ | |
300 | skb->pkt_type = PACKET_HOST; | |
301 | } | |
302 | ||
303 | /* send to netdevice */ | |
304 | err = dev_queue_xmit(skb); | |
305 | if (err > 0) | |
306 | err = net_xmit_errno(err); | |
307 | ||
c2ab7ac2 | 308 | if (err) { |
ce030edf | 309 | kfree_skb(newskb); |
c2ab7ac2 OH |
310 | return err; |
311 | } | |
312 | ||
313 | if (newskb) | |
481a8199 | 314 | netif_rx_ni(newskb); |
c2ab7ac2 | 315 | |
0d66548a OH |
316 | /* update statistics */ |
317 | can_stats.tx_frames++; | |
318 | can_stats.tx_frames_delta++; | |
319 | ||
c2ab7ac2 | 320 | return 0; |
8b01939f OH |
321 | |
322 | inval_skb: | |
323 | kfree_skb(skb); | |
324 | return err; | |
0d66548a OH |
325 | } |
326 | EXPORT_SYMBOL(can_send); | |
327 | ||
328 | /* | |
329 | * af_can rx path | |
330 | */ | |
331 | ||
332 | static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) | |
333 | { | |
20dd3850 OH |
334 | if (!dev) |
335 | return &can_rx_alldev_list; | |
336 | else | |
337 | return (struct dev_rcv_lists *)dev->ml_priv; | |
0d66548a OH |
338 | } |
339 | ||
45c70029 OH |
340 | /** |
341 | * effhash - hash function for 29 bit CAN identifier reduction | |
342 | * @can_id: 29 bit CAN identifier | |
343 | * | |
344 | * Description: | |
345 | * To reduce the linear traversal in one linked list of _single_ EFF CAN | |
346 | * frame subscriptions the 29 bit identifier is mapped to 10 bits. | |
347 | * (see CAN_EFF_RCV_HASH_BITS definition) | |
348 | * | |
349 | * Return: | |
350 | * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask ) | |
351 | */ | |
352 | static unsigned int effhash(canid_t can_id) | |
353 | { | |
354 | unsigned int hash; | |
355 | ||
356 | hash = can_id; | |
357 | hash ^= can_id >> CAN_EFF_RCV_HASH_BITS; | |
358 | hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS); | |
359 | ||
360 | return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1); | |
361 | } | |
362 | ||
d253eee2 OH |
363 | /** |
364 | * find_rcv_list - determine optimal filterlist inside device filter struct | |
365 | * @can_id: pointer to CAN identifier of a given can_filter | |
366 | * @mask: pointer to CAN mask of a given can_filter | |
367 | * @d: pointer to the device filter struct | |
368 | * | |
369 | * Description: | |
370 | * Returns the optimal filterlist to reduce the filter handling in the | |
371 | * receive path. This function is called by service functions that need | |
372 | * to register or unregister a can_filter in the filter lists. | |
373 | * | |
374 | * A filter matches in general, when | |
375 | * | |
376 | * <received_can_id> & mask == can_id & mask | |
377 | * | |
378 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe | |
379 | * relevant bits for the filter. | |
380 | * | |
381 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 OH |
382 | * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg |
383 | * frames there is a special filterlist and a special rx path filter handling. | |
d253eee2 OH |
384 | * |
385 | * Return: | |
386 | * Pointer to optimal filterlist for the given can_id/mask pair. | |
387 | * Constistency checked mask. | |
388 | * Reduced can_id to have a preprocessed filter compare value. | |
389 | */ | |
0d66548a OH |
390 | static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, |
391 | struct dev_rcv_lists *d) | |
392 | { | |
393 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
394 | ||
d6e640f9 | 395 | /* filter for error message frames in extra filterlist */ |
0d66548a | 396 | if (*mask & CAN_ERR_FLAG) { |
d253eee2 | 397 | /* clear CAN_ERR_FLAG in filter entry */ |
0d66548a OH |
398 | *mask &= CAN_ERR_MASK; |
399 | return &d->rx[RX_ERR]; | |
400 | } | |
401 | ||
d253eee2 OH |
402 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
403 | ||
404 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) | |
405 | ||
406 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ | |
407 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) | |
408 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); | |
0d66548a OH |
409 | |
410 | /* reduce condition testing at receive time */ | |
411 | *can_id &= *mask; | |
412 | ||
413 | /* inverse can_id/can_mask filter */ | |
414 | if (inv) | |
415 | return &d->rx[RX_INV]; | |
416 | ||
417 | /* mask == 0 => no condition testing at receive time */ | |
418 | if (!(*mask)) | |
419 | return &d->rx[RX_ALL]; | |
420 | ||
d253eee2 | 421 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
f64f9e71 JP |
422 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) && |
423 | !(*can_id & CAN_RTR_FLAG)) { | |
d253eee2 OH |
424 | |
425 | if (*can_id & CAN_EFF_FLAG) { | |
45c70029 OH |
426 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) |
427 | return &d->rx_eff[effhash(*can_id)]; | |
d253eee2 OH |
428 | } else { |
429 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) | |
430 | return &d->rx_sff[*can_id]; | |
0d66548a | 431 | } |
0d66548a OH |
432 | } |
433 | ||
434 | /* default: filter via can_id/can_mask */ | |
435 | return &d->rx[RX_FIL]; | |
436 | } | |
437 | ||
438 | /** | |
439 | * can_rx_register - subscribe CAN frames from a specific interface | |
440 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
441 | * @can_id: CAN identifier (see description) | |
442 | * @mask: CAN mask (see description) | |
443 | * @func: callback function on filter match | |
444 | * @data: returned parameter for callback function | |
3f79410c | 445 | * @ident: string for calling module identification |
0d66548a OH |
446 | * |
447 | * Description: | |
448 | * Invokes the callback function with the received sk_buff and the given | |
449 | * parameter 'data' on a matching receive filter. A filter matches, when | |
450 | * | |
451 | * <received_can_id> & mask == can_id & mask | |
452 | * | |
453 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 | 454 | * filter for error message frames (CAN_ERR_FLAG bit set in mask). |
0d66548a | 455 | * |
1fa17d4b OH |
456 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
457 | * the callback function is running. The callback function must *not* free | |
458 | * the given sk_buff while processing it's task. When the given sk_buff is | |
459 | * needed after the end of the callback function it must be cloned inside | |
460 | * the callback function with skb_clone(). | |
461 | * | |
0d66548a OH |
462 | * Return: |
463 | * 0 on success | |
464 | * -ENOMEM on missing cache mem to create subscription entry | |
465 | * -ENODEV unknown device | |
466 | */ | |
467 | int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask, | |
468 | void (*func)(struct sk_buff *, void *), void *data, | |
469 | char *ident) | |
470 | { | |
471 | struct receiver *r; | |
472 | struct hlist_head *rl; | |
473 | struct dev_rcv_lists *d; | |
474 | int err = 0; | |
475 | ||
476 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
477 | ||
8b64056d OH |
478 | if (dev && dev->type != ARPHRD_CAN) |
479 | return -ENODEV; | |
480 | ||
0d66548a OH |
481 | r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); |
482 | if (!r) | |
483 | return -ENOMEM; | |
484 | ||
485 | spin_lock(&can_rcvlists_lock); | |
486 | ||
487 | d = find_dev_rcv_lists(dev); | |
488 | if (d) { | |
489 | rl = find_rcv_list(&can_id, &mask, d); | |
490 | ||
491 | r->can_id = can_id; | |
492 | r->mask = mask; | |
493 | r->matches = 0; | |
494 | r->func = func; | |
495 | r->data = data; | |
496 | r->ident = ident; | |
497 | ||
498 | hlist_add_head_rcu(&r->list, rl); | |
499 | d->entries++; | |
500 | ||
501 | can_pstats.rcv_entries++; | |
502 | if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) | |
503 | can_pstats.rcv_entries_max = can_pstats.rcv_entries; | |
504 | } else { | |
505 | kmem_cache_free(rcv_cache, r); | |
506 | err = -ENODEV; | |
507 | } | |
508 | ||
509 | spin_unlock(&can_rcvlists_lock); | |
510 | ||
511 | return err; | |
512 | } | |
513 | EXPORT_SYMBOL(can_rx_register); | |
514 | ||
0d66548a OH |
515 | /* |
516 | * can_rx_delete_receiver - rcu callback for single receiver entry removal | |
517 | */ | |
518 | static void can_rx_delete_receiver(struct rcu_head *rp) | |
519 | { | |
520 | struct receiver *r = container_of(rp, struct receiver, rcu); | |
521 | ||
522 | kmem_cache_free(rcv_cache, r); | |
523 | } | |
524 | ||
525 | /** | |
526 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
527 | * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list) | |
528 | * @can_id: CAN identifier | |
529 | * @mask: CAN mask | |
530 | * @func: callback function on filter match | |
531 | * @data: returned parameter for callback function | |
532 | * | |
533 | * Description: | |
534 | * Removes subscription entry depending on given (subscription) values. | |
535 | */ | |
536 | void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, | |
537 | void (*func)(struct sk_buff *, void *), void *data) | |
538 | { | |
539 | struct receiver *r = NULL; | |
540 | struct hlist_head *rl; | |
0d66548a OH |
541 | struct dev_rcv_lists *d; |
542 | ||
8b64056d OH |
543 | if (dev && dev->type != ARPHRD_CAN) |
544 | return; | |
545 | ||
0d66548a OH |
546 | spin_lock(&can_rcvlists_lock); |
547 | ||
548 | d = find_dev_rcv_lists(dev); | |
549 | if (!d) { | |
f4f3efda | 550 | pr_err("BUG: receive list not found for " |
0d66548a OH |
551 | "dev %s, id %03X, mask %03X\n", |
552 | DNAME(dev), can_id, mask); | |
553 | goto out; | |
554 | } | |
555 | ||
556 | rl = find_rcv_list(&can_id, &mask, d); | |
557 | ||
558 | /* | |
559 | * Search the receiver list for the item to delete. This should | |
560 | * exist, since no receiver may be unregistered that hasn't | |
561 | * been registered before. | |
562 | */ | |
563 | ||
b67bfe0d | 564 | hlist_for_each_entry_rcu(r, rl, list) { |
f64f9e71 JP |
565 | if (r->can_id == can_id && r->mask == mask && |
566 | r->func == func && r->data == data) | |
0d66548a OH |
567 | break; |
568 | } | |
569 | ||
570 | /* | |
c9bbb75f OH |
571 | * Check for bugs in CAN protocol implementations using af_can.c: |
572 | * 'r' will be NULL if no matching list item was found for removal. | |
0d66548a OH |
573 | */ |
574 | ||
b67bfe0d | 575 | if (!r) { |
c9bbb75f OH |
576 | WARN(1, "BUG: receive list entry not found for dev %s, " |
577 | "id %03X, mask %03X\n", DNAME(dev), can_id, mask); | |
0d66548a OH |
578 | goto out; |
579 | } | |
580 | ||
581 | hlist_del_rcu(&r->list); | |
582 | d->entries--; | |
583 | ||
584 | if (can_pstats.rcv_entries > 0) | |
585 | can_pstats.rcv_entries--; | |
586 | ||
587 | /* remove device structure requested by NETDEV_UNREGISTER */ | |
20dd3850 OH |
588 | if (d->remove_on_zero_entries && !d->entries) { |
589 | kfree(d); | |
590 | dev->ml_priv = NULL; | |
591 | } | |
0d66548a OH |
592 | |
593 | out: | |
594 | spin_unlock(&can_rcvlists_lock); | |
595 | ||
596 | /* schedule the receiver item for deletion */ | |
597 | if (r) | |
598 | call_rcu(&r->rcu, can_rx_delete_receiver); | |
0d66548a OH |
599 | } |
600 | EXPORT_SYMBOL(can_rx_unregister); | |
601 | ||
602 | static inline void deliver(struct sk_buff *skb, struct receiver *r) | |
603 | { | |
1fa17d4b OH |
604 | r->func(skb, r->data); |
605 | r->matches++; | |
0d66548a OH |
606 | } |
607 | ||
608 | static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) | |
609 | { | |
610 | struct receiver *r; | |
0d66548a OH |
611 | int matches = 0; |
612 | struct can_frame *cf = (struct can_frame *)skb->data; | |
613 | canid_t can_id = cf->can_id; | |
614 | ||
615 | if (d->entries == 0) | |
616 | return 0; | |
617 | ||
618 | if (can_id & CAN_ERR_FLAG) { | |
d6e640f9 | 619 | /* check for error message frame entries only */ |
b67bfe0d | 620 | hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) { |
0d66548a OH |
621 | if (can_id & r->mask) { |
622 | deliver(skb, r); | |
623 | matches++; | |
624 | } | |
625 | } | |
626 | return matches; | |
627 | } | |
628 | ||
629 | /* check for unfiltered entries */ | |
b67bfe0d | 630 | hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) { |
0d66548a OH |
631 | deliver(skb, r); |
632 | matches++; | |
633 | } | |
634 | ||
635 | /* check for can_id/mask entries */ | |
b67bfe0d | 636 | hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) { |
0d66548a OH |
637 | if ((can_id & r->mask) == r->can_id) { |
638 | deliver(skb, r); | |
639 | matches++; | |
640 | } | |
641 | } | |
642 | ||
643 | /* check for inverted can_id/mask entries */ | |
b67bfe0d | 644 | hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) { |
0d66548a OH |
645 | if ((can_id & r->mask) != r->can_id) { |
646 | deliver(skb, r); | |
647 | matches++; | |
648 | } | |
649 | } | |
650 | ||
f706644d OH |
651 | /* check filterlists for single non-RTR can_ids */ |
652 | if (can_id & CAN_RTR_FLAG) | |
653 | return matches; | |
654 | ||
0d66548a | 655 | if (can_id & CAN_EFF_FLAG) { |
45c70029 | 656 | hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) { |
0d66548a OH |
657 | if (r->can_id == can_id) { |
658 | deliver(skb, r); | |
659 | matches++; | |
660 | } | |
661 | } | |
662 | } else { | |
663 | can_id &= CAN_SFF_MASK; | |
b67bfe0d | 664 | hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) { |
0d66548a OH |
665 | deliver(skb, r); |
666 | matches++; | |
667 | } | |
668 | } | |
669 | ||
670 | return matches; | |
671 | } | |
672 | ||
8b01939f | 673 | static void can_receive(struct sk_buff *skb, struct net_device *dev) |
0d66548a OH |
674 | { |
675 | struct dev_rcv_lists *d; | |
676 | int matches; | |
677 | ||
0d66548a OH |
678 | /* update statistics */ |
679 | can_stats.rx_frames++; | |
680 | can_stats.rx_frames_delta++; | |
681 | ||
682 | rcu_read_lock(); | |
683 | ||
684 | /* deliver the packet to sockets listening on all devices */ | |
685 | matches = can_rcv_filter(&can_rx_alldev_list, skb); | |
686 | ||
687 | /* find receive list for this device */ | |
688 | d = find_dev_rcv_lists(dev); | |
689 | if (d) | |
690 | matches += can_rcv_filter(d, skb); | |
691 | ||
692 | rcu_read_unlock(); | |
693 | ||
62bcaa13 OH |
694 | /* consume the skbuff allocated by the netdevice driver */ |
695 | consume_skb(skb); | |
0d66548a OH |
696 | |
697 | if (matches > 0) { | |
698 | can_stats.matches++; | |
699 | can_stats.matches_delta++; | |
700 | } | |
8b01939f OH |
701 | } |
702 | ||
703 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
704 | struct packet_type *pt, struct net_device *orig_dev) | |
705 | { | |
706 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; | |
0d66548a | 707 | |
8b01939f OH |
708 | if (unlikely(!net_eq(dev_net(dev), &init_net))) |
709 | goto drop; | |
710 | ||
711 | if (WARN_ONCE(dev->type != ARPHRD_CAN || | |
712 | skb->len != CAN_MTU || | |
713 | cfd->len > CAN_MAX_DLEN, | |
714 | "PF_CAN: dropped non conform CAN skbuf: " | |
715 | "dev type %d, len %d, datalen %d\n", | |
716 | dev->type, skb->len, cfd->len)) | |
717 | goto drop; | |
718 | ||
719 | can_receive(skb, dev); | |
720 | return NET_RX_SUCCESS; | |
721 | ||
722 | drop: | |
723 | kfree_skb(skb); | |
724 | return NET_RX_DROP; | |
725 | } | |
726 | ||
727 | static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, | |
728 | struct packet_type *pt, struct net_device *orig_dev) | |
729 | { | |
730 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; | |
731 | ||
732 | if (unlikely(!net_eq(dev_net(dev), &init_net))) | |
733 | goto drop; | |
734 | ||
735 | if (WARN_ONCE(dev->type != ARPHRD_CAN || | |
736 | skb->len != CANFD_MTU || | |
737 | cfd->len > CANFD_MAX_DLEN, | |
738 | "PF_CAN: dropped non conform CAN FD skbuf: " | |
739 | "dev type %d, len %d, datalen %d\n", | |
740 | dev->type, skb->len, cfd->len)) | |
741 | goto drop; | |
742 | ||
743 | can_receive(skb, dev); | |
6ca8b990 | 744 | return NET_RX_SUCCESS; |
1758c094 OH |
745 | |
746 | drop: | |
747 | kfree_skb(skb); | |
6ca8b990 | 748 | return NET_RX_DROP; |
0d66548a OH |
749 | } |
750 | ||
751 | /* | |
752 | * af_can protocol functions | |
753 | */ | |
754 | ||
755 | /** | |
756 | * can_proto_register - register CAN transport protocol | |
757 | * @cp: pointer to CAN protocol structure | |
758 | * | |
759 | * Return: | |
760 | * 0 on success | |
761 | * -EINVAL invalid (out of range) protocol number | |
762 | * -EBUSY protocol already in use | |
763 | * -ENOBUF if proto_register() fails | |
764 | */ | |
1650629d | 765 | int can_proto_register(const struct can_proto *cp) |
0d66548a OH |
766 | { |
767 | int proto = cp->protocol; | |
768 | int err = 0; | |
769 | ||
770 | if (proto < 0 || proto >= CAN_NPROTO) { | |
f4f3efda | 771 | pr_err("can: protocol number %d out of range\n", proto); |
0d66548a OH |
772 | return -EINVAL; |
773 | } | |
774 | ||
a2fea5f1 UT |
775 | err = proto_register(cp->prot, 0); |
776 | if (err < 0) | |
777 | return err; | |
778 | ||
1ca050d9 OH |
779 | mutex_lock(&proto_tab_lock); |
780 | ||
0d66548a | 781 | if (proto_tab[proto]) { |
f4f3efda | 782 | pr_err("can: protocol %d already registered\n", proto); |
0d66548a | 783 | err = -EBUSY; |
53914b67 | 784 | } else |
a9b3cd7f | 785 | RCU_INIT_POINTER(proto_tab[proto], cp); |
a2fea5f1 | 786 | |
1ca050d9 | 787 | mutex_unlock(&proto_tab_lock); |
0d66548a | 788 | |
0d66548a | 789 | if (err < 0) |
a2fea5f1 | 790 | proto_unregister(cp->prot); |
0d66548a OH |
791 | |
792 | return err; | |
793 | } | |
794 | EXPORT_SYMBOL(can_proto_register); | |
795 | ||
796 | /** | |
797 | * can_proto_unregister - unregister CAN transport protocol | |
798 | * @cp: pointer to CAN protocol structure | |
799 | */ | |
1650629d | 800 | void can_proto_unregister(const struct can_proto *cp) |
0d66548a OH |
801 | { |
802 | int proto = cp->protocol; | |
803 | ||
1ca050d9 OH |
804 | mutex_lock(&proto_tab_lock); |
805 | BUG_ON(proto_tab[proto] != cp); | |
a9b3cd7f | 806 | RCU_INIT_POINTER(proto_tab[proto], NULL); |
1ca050d9 OH |
807 | mutex_unlock(&proto_tab_lock); |
808 | ||
809 | synchronize_rcu(); | |
a2fea5f1 UT |
810 | |
811 | proto_unregister(cp->prot); | |
0d66548a OH |
812 | } |
813 | EXPORT_SYMBOL(can_proto_unregister); | |
814 | ||
815 | /* | |
816 | * af_can notifier to create/remove CAN netdevice specific structs | |
817 | */ | |
818 | static int can_notifier(struct notifier_block *nb, unsigned long msg, | |
351638e7 | 819 | void *ptr) |
0d66548a | 820 | { |
351638e7 | 821 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
0d66548a OH |
822 | struct dev_rcv_lists *d; |
823 | ||
721499e8 | 824 | if (!net_eq(dev_net(dev), &init_net)) |
0d66548a OH |
825 | return NOTIFY_DONE; |
826 | ||
827 | if (dev->type != ARPHRD_CAN) | |
828 | return NOTIFY_DONE; | |
829 | ||
830 | switch (msg) { | |
831 | ||
832 | case NETDEV_REGISTER: | |
833 | ||
20dd3850 | 834 | /* create new dev_rcv_lists for this device */ |
0d66548a | 835 | d = kzalloc(sizeof(*d), GFP_KERNEL); |
f4f3efda | 836 | if (!d) |
0d66548a | 837 | return NOTIFY_DONE; |
20dd3850 OH |
838 | BUG_ON(dev->ml_priv); |
839 | dev->ml_priv = d; | |
0d66548a OH |
840 | |
841 | break; | |
842 | ||
843 | case NETDEV_UNREGISTER: | |
844 | spin_lock(&can_rcvlists_lock); | |
845 | ||
20dd3850 | 846 | d = dev->ml_priv; |
0d66548a | 847 | if (d) { |
20dd3850 | 848 | if (d->entries) |
0d66548a | 849 | d->remove_on_zero_entries = 1; |
20dd3850 OH |
850 | else { |
851 | kfree(d); | |
852 | dev->ml_priv = NULL; | |
853 | } | |
0d66548a | 854 | } else |
f4f3efda VI |
855 | pr_err("can: notifier: receive list not found for dev " |
856 | "%s\n", dev->name); | |
0d66548a OH |
857 | |
858 | spin_unlock(&can_rcvlists_lock); | |
859 | ||
0d66548a OH |
860 | break; |
861 | } | |
862 | ||
863 | return NOTIFY_DONE; | |
864 | } | |
865 | ||
866 | /* | |
867 | * af_can module init/exit functions | |
868 | */ | |
869 | ||
870 | static struct packet_type can_packet __read_mostly = { | |
09640e63 | 871 | .type = cpu_to_be16(ETH_P_CAN), |
0d66548a OH |
872 | .func = can_rcv, |
873 | }; | |
874 | ||
8b01939f OH |
875 | static struct packet_type canfd_packet __read_mostly = { |
876 | .type = cpu_to_be16(ETH_P_CANFD), | |
877 | .func = canfd_rcv, | |
878 | }; | |
879 | ||
ec1b4cf7 | 880 | static const struct net_proto_family can_family_ops = { |
0d66548a OH |
881 | .family = PF_CAN, |
882 | .create = can_create, | |
883 | .owner = THIS_MODULE, | |
884 | }; | |
885 | ||
886 | /* notifier block for netdevice event */ | |
887 | static struct notifier_block can_netdev_notifier __read_mostly = { | |
888 | .notifier_call = can_notifier, | |
889 | }; | |
890 | ||
891 | static __init int can_init(void) | |
892 | { | |
7c941636 OH |
893 | /* check for correct padding to be able to use the structs similarly */ |
894 | BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) != | |
895 | offsetof(struct canfd_frame, len) || | |
896 | offsetof(struct can_frame, data) != | |
897 | offsetof(struct canfd_frame, data)); | |
898 | ||
0d66548a OH |
899 | printk(banner); |
900 | ||
20dd3850 OH |
901 | memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list)); |
902 | ||
0d66548a OH |
903 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), |
904 | 0, 0, NULL); | |
905 | if (!rcv_cache) | |
906 | return -ENOMEM; | |
907 | ||
0d66548a OH |
908 | if (stats_timer) { |
909 | /* the statistics are updated every second (timer triggered) */ | |
910 | setup_timer(&can_stattimer, can_stat_update, 0); | |
911 | mod_timer(&can_stattimer, round_jiffies(jiffies + HZ)); | |
912 | } else | |
913 | can_stattimer.function = NULL; | |
914 | ||
915 | can_init_proc(); | |
916 | ||
917 | /* protocol register */ | |
918 | sock_register(&can_family_ops); | |
919 | register_netdevice_notifier(&can_netdev_notifier); | |
920 | dev_add_pack(&can_packet); | |
8b01939f | 921 | dev_add_pack(&canfd_packet); |
0d66548a OH |
922 | |
923 | return 0; | |
924 | } | |
925 | ||
926 | static __exit void can_exit(void) | |
927 | { | |
20dd3850 | 928 | struct net_device *dev; |
0d66548a OH |
929 | |
930 | if (stats_timer) | |
d9e64f83 | 931 | del_timer_sync(&can_stattimer); |
0d66548a OH |
932 | |
933 | can_remove_proc(); | |
934 | ||
935 | /* protocol unregister */ | |
8b01939f | 936 | dev_remove_pack(&canfd_packet); |
0d66548a OH |
937 | dev_remove_pack(&can_packet); |
938 | unregister_netdevice_notifier(&can_netdev_notifier); | |
939 | sock_unregister(PF_CAN); | |
940 | ||
20dd3850 OH |
941 | /* remove created dev_rcv_lists from still registered CAN devices */ |
942 | rcu_read_lock(); | |
943 | for_each_netdev_rcu(&init_net, dev) { | |
f4f3efda | 944 | if (dev->type == ARPHRD_CAN && dev->ml_priv) { |
20dd3850 OH |
945 | |
946 | struct dev_rcv_lists *d = dev->ml_priv; | |
947 | ||
948 | BUG_ON(d->entries); | |
949 | kfree(d); | |
950 | dev->ml_priv = NULL; | |
951 | } | |
0d66548a | 952 | } |
20dd3850 | 953 | rcu_read_unlock(); |
0d66548a | 954 | |
382bfeec JDB |
955 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
956 | ||
0d66548a OH |
957 | kmem_cache_destroy(rcv_cache); |
958 | } | |
959 | ||
960 | module_init(can_init); | |
961 | module_exit(can_exit); |