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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 | ||
0d66548a OH |
67 | MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); |
68 | MODULE_LICENSE("Dual BSD/GPL"); | |
69 | MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, " | |
70 | "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); | |
71 | ||
72 | MODULE_ALIAS_NETPROTO(PF_CAN); | |
73 | ||
74 | static int stats_timer __read_mostly = 1; | |
75 | module_param(stats_timer, int, S_IRUGO); | |
76 | MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); | |
77 | ||
0d66548a OH |
78 | static struct kmem_cache *rcv_cache __read_mostly; |
79 | ||
80 | /* table of registered CAN protocols */ | |
1650629d | 81 | static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly; |
1ca050d9 | 82 | static DEFINE_MUTEX(proto_tab_lock); |
0d66548a OH |
83 | |
84 | struct timer_list can_stattimer; /* timer for statistics update */ | |
85 | struct s_stats can_stats; /* packet statistics */ | |
86 | struct s_pstats can_pstats; /* receive list statistics */ | |
87 | ||
d3b58c47 OH |
88 | static atomic_t skbcounter = ATOMIC_INIT(0); |
89 | ||
0d66548a OH |
90 | /* |
91 | * af_can socket functions | |
92 | */ | |
93 | ||
53914b67 | 94 | int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) |
0d66548a OH |
95 | { |
96 | struct sock *sk = sock->sk; | |
97 | ||
98 | switch (cmd) { | |
99 | ||
100 | case SIOCGSTAMP: | |
101 | return sock_get_timestamp(sk, (struct timeval __user *)arg); | |
102 | ||
103 | default: | |
104 | return -ENOIOCTLCMD; | |
105 | } | |
106 | } | |
53914b67 | 107 | EXPORT_SYMBOL(can_ioctl); |
0d66548a OH |
108 | |
109 | static void can_sock_destruct(struct sock *sk) | |
110 | { | |
111 | skb_queue_purge(&sk->sk_receive_queue); | |
112 | } | |
113 | ||
c8d55a9d | 114 | static const struct can_proto *can_get_proto(int protocol) |
1ca050d9 | 115 | { |
1650629d | 116 | const struct can_proto *cp; |
1ca050d9 OH |
117 | |
118 | rcu_read_lock(); | |
119 | cp = rcu_dereference(proto_tab[protocol]); | |
120 | if (cp && !try_module_get(cp->prot->owner)) | |
121 | cp = NULL; | |
122 | rcu_read_unlock(); | |
123 | ||
124 | return cp; | |
125 | } | |
126 | ||
c8d55a9d KVD |
127 | static inline void can_put_proto(const struct can_proto *cp) |
128 | { | |
129 | module_put(cp->prot->owner); | |
130 | } | |
131 | ||
3f378b68 EP |
132 | static int can_create(struct net *net, struct socket *sock, int protocol, |
133 | int kern) | |
0d66548a OH |
134 | { |
135 | struct sock *sk; | |
1650629d | 136 | const struct can_proto *cp; |
0d66548a OH |
137 | int err = 0; |
138 | ||
139 | sock->state = SS_UNCONNECTED; | |
140 | ||
141 | if (protocol < 0 || protocol >= CAN_NPROTO) | |
142 | return -EINVAL; | |
143 | ||
c8d55a9d | 144 | cp = can_get_proto(protocol); |
1ca050d9 | 145 | |
95a5afca | 146 | #ifdef CONFIG_MODULES |
1ca050d9 OH |
147 | if (!cp) { |
148 | /* try to load protocol module if kernel is modular */ | |
149 | ||
5423dd67 | 150 | err = request_module("can-proto-%d", protocol); |
0d66548a OH |
151 | |
152 | /* | |
153 | * In case of error we only print a message but don't | |
154 | * return the error code immediately. Below we will | |
155 | * return -EPROTONOSUPPORT | |
156 | */ | |
d751e623 MZ |
157 | if (err) |
158 | printk_ratelimited(KERN_ERR "can: request_module " | |
5423dd67 | 159 | "(can-proto-%d) failed.\n", protocol); |
1ca050d9 | 160 | |
c8d55a9d | 161 | cp = can_get_proto(protocol); |
0d66548a | 162 | } |
5423dd67 | 163 | #endif |
0d66548a | 164 | |
0d66548a OH |
165 | /* check for available protocol and correct usage */ |
166 | ||
167 | if (!cp) | |
168 | return -EPROTONOSUPPORT; | |
169 | ||
170 | if (cp->type != sock->type) { | |
1ca050d9 | 171 | err = -EPROTOTYPE; |
0d66548a OH |
172 | goto errout; |
173 | } | |
174 | ||
0d66548a OH |
175 | sock->ops = cp->ops; |
176 | ||
11aa9c28 | 177 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern); |
0d66548a OH |
178 | if (!sk) { |
179 | err = -ENOMEM; | |
180 | goto errout; | |
181 | } | |
182 | ||
183 | sock_init_data(sock, sk); | |
184 | sk->sk_destruct = can_sock_destruct; | |
185 | ||
186 | if (sk->sk_prot->init) | |
187 | err = sk->sk_prot->init(sk); | |
188 | ||
189 | if (err) { | |
190 | /* release sk on errors */ | |
191 | sock_orphan(sk); | |
192 | sock_put(sk); | |
193 | } | |
194 | ||
195 | errout: | |
c8d55a9d | 196 | can_put_proto(cp); |
0d66548a OH |
197 | return err; |
198 | } | |
199 | ||
200 | /* | |
201 | * af_can tx path | |
202 | */ | |
203 | ||
204 | /** | |
205 | * can_send - transmit a CAN frame (optional with local loopback) | |
206 | * @skb: pointer to socket buffer with CAN frame in data section | |
207 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
208 | * | |
481a8199 OH |
209 | * Due to the loopback this routine must not be called from hardirq context. |
210 | * | |
0d66548a OH |
211 | * Return: |
212 | * 0 on success | |
213 | * -ENETDOWN when the selected interface is down | |
214 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
215 | * -ENOMEM when local loopback failed at calling skb_clone() | |
216 | * -EPERM when trying to send on a non-CAN interface | |
8b01939f | 217 | * -EMSGSIZE CAN frame size is bigger than CAN interface MTU |
7f2d38eb | 218 | * -EINVAL when the skb->data does not contain a valid CAN frame |
0d66548a OH |
219 | */ |
220 | int can_send(struct sk_buff *skb, int loop) | |
221 | { | |
c2ab7ac2 | 222 | struct sk_buff *newskb = NULL; |
8b01939f OH |
223 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; |
224 | int err = -EINVAL; | |
225 | ||
226 | if (skb->len == CAN_MTU) { | |
227 | skb->protocol = htons(ETH_P_CAN); | |
228 | if (unlikely(cfd->len > CAN_MAX_DLEN)) | |
229 | goto inval_skb; | |
230 | } else if (skb->len == CANFD_MTU) { | |
231 | skb->protocol = htons(ETH_P_CANFD); | |
232 | if (unlikely(cfd->len > CANFD_MAX_DLEN)) | |
233 | goto inval_skb; | |
234 | } else | |
235 | goto inval_skb; | |
0d66548a | 236 | |
8b01939f OH |
237 | /* |
238 | * Make sure the CAN frame can pass the selected CAN netdevice. | |
239 | * As structs can_frame and canfd_frame are similar, we can provide | |
240 | * CAN FD frames to legacy CAN drivers as long as the length is <= 8 | |
241 | */ | |
242 | if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) { | |
243 | err = -EMSGSIZE; | |
244 | goto inval_skb; | |
7f2d38eb OH |
245 | } |
246 | ||
8b01939f OH |
247 | if (unlikely(skb->dev->type != ARPHRD_CAN)) { |
248 | err = -EPERM; | |
249 | goto inval_skb; | |
0d66548a OH |
250 | } |
251 | ||
8b01939f OH |
252 | if (unlikely(!(skb->dev->flags & IFF_UP))) { |
253 | err = -ENETDOWN; | |
254 | goto inval_skb; | |
0d66548a OH |
255 | } |
256 | ||
96943901 OH |
257 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
258 | ||
259 | skb_reset_mac_header(skb); | |
0d66548a OH |
260 | skb_reset_network_header(skb); |
261 | skb_reset_transport_header(skb); | |
262 | ||
263 | if (loop) { | |
264 | /* local loopback of sent CAN frames */ | |
265 | ||
266 | /* indication for the CAN driver: do loopback */ | |
267 | skb->pkt_type = PACKET_LOOPBACK; | |
268 | ||
269 | /* | |
270 | * The reference to the originating sock may be required | |
271 | * by the receiving socket to check whether the frame is | |
272 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS | |
273 | * Therefore we have to ensure that skb->sk remains the | |
274 | * reference to the originating sock by restoring skb->sk | |
275 | * after each skb_clone() or skb_orphan() usage. | |
276 | */ | |
277 | ||
278 | if (!(skb->dev->flags & IFF_ECHO)) { | |
279 | /* | |
280 | * If the interface is not capable to do loopback | |
281 | * itself, we do it here. | |
282 | */ | |
c2ab7ac2 | 283 | newskb = skb_clone(skb, GFP_ATOMIC); |
0d66548a OH |
284 | if (!newskb) { |
285 | kfree_skb(skb); | |
286 | return -ENOMEM; | |
287 | } | |
288 | ||
0ae89beb | 289 | can_skb_set_owner(newskb, skb->sk); |
0d66548a OH |
290 | newskb->ip_summed = CHECKSUM_UNNECESSARY; |
291 | newskb->pkt_type = PACKET_BROADCAST; | |
0d66548a OH |
292 | } |
293 | } else { | |
294 | /* indication for the CAN driver: no loopback required */ | |
295 | skb->pkt_type = PACKET_HOST; | |
296 | } | |
297 | ||
298 | /* send to netdevice */ | |
299 | err = dev_queue_xmit(skb); | |
300 | if (err > 0) | |
301 | err = net_xmit_errno(err); | |
302 | ||
c2ab7ac2 | 303 | if (err) { |
ce030edf | 304 | kfree_skb(newskb); |
c2ab7ac2 OH |
305 | return err; |
306 | } | |
307 | ||
d3b58c47 | 308 | if (newskb) |
481a8199 | 309 | netif_rx_ni(newskb); |
c2ab7ac2 | 310 | |
0d66548a OH |
311 | /* update statistics */ |
312 | can_stats.tx_frames++; | |
313 | can_stats.tx_frames_delta++; | |
314 | ||
c2ab7ac2 | 315 | return 0; |
8b01939f OH |
316 | |
317 | inval_skb: | |
318 | kfree_skb(skb); | |
319 | return err; | |
0d66548a OH |
320 | } |
321 | EXPORT_SYMBOL(can_send); | |
322 | ||
323 | /* | |
324 | * af_can rx path | |
325 | */ | |
326 | ||
8e8cda6d MK |
327 | static struct dev_rcv_lists *find_dev_rcv_lists(struct net *net, |
328 | struct net_device *dev) | |
0d66548a | 329 | { |
20dd3850 | 330 | if (!dev) |
8e8cda6d | 331 | return net->can.can_rx_alldev_list; |
20dd3850 OH |
332 | else |
333 | return (struct dev_rcv_lists *)dev->ml_priv; | |
0d66548a OH |
334 | } |
335 | ||
45c70029 OH |
336 | /** |
337 | * effhash - hash function for 29 bit CAN identifier reduction | |
338 | * @can_id: 29 bit CAN identifier | |
339 | * | |
340 | * Description: | |
341 | * To reduce the linear traversal in one linked list of _single_ EFF CAN | |
342 | * frame subscriptions the 29 bit identifier is mapped to 10 bits. | |
343 | * (see CAN_EFF_RCV_HASH_BITS definition) | |
344 | * | |
345 | * Return: | |
346 | * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask ) | |
347 | */ | |
348 | static unsigned int effhash(canid_t can_id) | |
349 | { | |
350 | unsigned int hash; | |
351 | ||
352 | hash = can_id; | |
353 | hash ^= can_id >> CAN_EFF_RCV_HASH_BITS; | |
354 | hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS); | |
355 | ||
356 | return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1); | |
357 | } | |
358 | ||
d253eee2 OH |
359 | /** |
360 | * find_rcv_list - determine optimal filterlist inside device filter struct | |
361 | * @can_id: pointer to CAN identifier of a given can_filter | |
362 | * @mask: pointer to CAN mask of a given can_filter | |
363 | * @d: pointer to the device filter struct | |
364 | * | |
365 | * Description: | |
366 | * Returns the optimal filterlist to reduce the filter handling in the | |
367 | * receive path. This function is called by service functions that need | |
368 | * to register or unregister a can_filter in the filter lists. | |
369 | * | |
370 | * A filter matches in general, when | |
371 | * | |
372 | * <received_can_id> & mask == can_id & mask | |
373 | * | |
374 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe | |
375 | * relevant bits for the filter. | |
376 | * | |
377 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 OH |
378 | * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg |
379 | * frames there is a special filterlist and a special rx path filter handling. | |
d253eee2 OH |
380 | * |
381 | * Return: | |
382 | * Pointer to optimal filterlist for the given can_id/mask pair. | |
383 | * Constistency checked mask. | |
384 | * Reduced can_id to have a preprocessed filter compare value. | |
385 | */ | |
0d66548a OH |
386 | static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, |
387 | struct dev_rcv_lists *d) | |
388 | { | |
389 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
390 | ||
d6e640f9 | 391 | /* filter for error message frames in extra filterlist */ |
0d66548a | 392 | if (*mask & CAN_ERR_FLAG) { |
d253eee2 | 393 | /* clear CAN_ERR_FLAG in filter entry */ |
0d66548a OH |
394 | *mask &= CAN_ERR_MASK; |
395 | return &d->rx[RX_ERR]; | |
396 | } | |
397 | ||
d253eee2 OH |
398 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
399 | ||
400 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) | |
401 | ||
402 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ | |
403 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) | |
404 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); | |
0d66548a OH |
405 | |
406 | /* reduce condition testing at receive time */ | |
407 | *can_id &= *mask; | |
408 | ||
409 | /* inverse can_id/can_mask filter */ | |
410 | if (inv) | |
411 | return &d->rx[RX_INV]; | |
412 | ||
413 | /* mask == 0 => no condition testing at receive time */ | |
414 | if (!(*mask)) | |
415 | return &d->rx[RX_ALL]; | |
416 | ||
d253eee2 | 417 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
f64f9e71 JP |
418 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) && |
419 | !(*can_id & CAN_RTR_FLAG)) { | |
d253eee2 OH |
420 | |
421 | if (*can_id & CAN_EFF_FLAG) { | |
45c70029 OH |
422 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) |
423 | return &d->rx_eff[effhash(*can_id)]; | |
d253eee2 OH |
424 | } else { |
425 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) | |
426 | return &d->rx_sff[*can_id]; | |
0d66548a | 427 | } |
0d66548a OH |
428 | } |
429 | ||
430 | /* default: filter via can_id/can_mask */ | |
431 | return &d->rx[RX_FIL]; | |
432 | } | |
433 | ||
434 | /** | |
435 | * can_rx_register - subscribe CAN frames from a specific interface | |
436 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
437 | * @can_id: CAN identifier (see description) | |
438 | * @mask: CAN mask (see description) | |
439 | * @func: callback function on filter match | |
440 | * @data: returned parameter for callback function | |
3f79410c | 441 | * @ident: string for calling module identification |
f1712c73 | 442 | * @sk: socket pointer (might be NULL) |
0d66548a OH |
443 | * |
444 | * Description: | |
445 | * Invokes the callback function with the received sk_buff and the given | |
446 | * parameter 'data' on a matching receive filter. A filter matches, when | |
447 | * | |
448 | * <received_can_id> & mask == can_id & mask | |
449 | * | |
450 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 | 451 | * filter for error message frames (CAN_ERR_FLAG bit set in mask). |
0d66548a | 452 | * |
1fa17d4b OH |
453 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
454 | * the callback function is running. The callback function must *not* free | |
455 | * the given sk_buff while processing it's task. When the given sk_buff is | |
456 | * needed after the end of the callback function it must be cloned inside | |
457 | * the callback function with skb_clone(). | |
458 | * | |
0d66548a OH |
459 | * Return: |
460 | * 0 on success | |
461 | * -ENOMEM on missing cache mem to create subscription entry | |
462 | * -ENODEV unknown device | |
463 | */ | |
8e8cda6d MK |
464 | int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, |
465 | canid_t mask, void (*func)(struct sk_buff *, void *), | |
466 | void *data, char *ident, struct sock *sk) | |
0d66548a OH |
467 | { |
468 | struct receiver *r; | |
469 | struct hlist_head *rl; | |
470 | struct dev_rcv_lists *d; | |
471 | int err = 0; | |
472 | ||
473 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
474 | ||
8b64056d OH |
475 | if (dev && dev->type != ARPHRD_CAN) |
476 | return -ENODEV; | |
477 | ||
8e8cda6d MK |
478 | if (dev && !net_eq(net, dev_net(dev))) |
479 | return -ENODEV; | |
480 | ||
0d66548a OH |
481 | r = kmem_cache_alloc(rcv_cache, GFP_KERNEL); |
482 | if (!r) | |
483 | return -ENOMEM; | |
484 | ||
8e8cda6d | 485 | spin_lock(&net->can.can_rcvlists_lock); |
0d66548a | 486 | |
8e8cda6d | 487 | d = find_dev_rcv_lists(net, dev); |
0d66548a OH |
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; | |
f1712c73 | 497 | r->sk = sk; |
0d66548a OH |
498 | |
499 | hlist_add_head_rcu(&r->list, rl); | |
500 | d->entries++; | |
501 | ||
502 | can_pstats.rcv_entries++; | |
503 | if (can_pstats.rcv_entries_max < can_pstats.rcv_entries) | |
504 | can_pstats.rcv_entries_max = can_pstats.rcv_entries; | |
505 | } else { | |
506 | kmem_cache_free(rcv_cache, r); | |
507 | err = -ENODEV; | |
508 | } | |
509 | ||
8e8cda6d | 510 | spin_unlock(&net->can.can_rcvlists_lock); |
0d66548a OH |
511 | |
512 | return err; | |
513 | } | |
514 | EXPORT_SYMBOL(can_rx_register); | |
515 | ||
0d66548a OH |
516 | /* |
517 | * can_rx_delete_receiver - rcu callback for single receiver entry removal | |
518 | */ | |
519 | static void can_rx_delete_receiver(struct rcu_head *rp) | |
520 | { | |
521 | struct receiver *r = container_of(rp, struct receiver, rcu); | |
f1712c73 | 522 | struct sock *sk = r->sk; |
0d66548a OH |
523 | |
524 | kmem_cache_free(rcv_cache, r); | |
f1712c73 ED |
525 | if (sk) |
526 | sock_put(sk); | |
0d66548a OH |
527 | } |
528 | ||
529 | /** | |
530 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
069f8457 | 531 | * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list) |
0d66548a OH |
532 | * @can_id: CAN identifier |
533 | * @mask: CAN mask | |
534 | * @func: callback function on filter match | |
535 | * @data: returned parameter for callback function | |
536 | * | |
537 | * Description: | |
538 | * Removes subscription entry depending on given (subscription) values. | |
539 | */ | |
8e8cda6d MK |
540 | void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id, |
541 | canid_t mask, void (*func)(struct sk_buff *, void *), | |
542 | void *data) | |
0d66548a OH |
543 | { |
544 | struct receiver *r = NULL; | |
545 | struct hlist_head *rl; | |
0d66548a OH |
546 | struct dev_rcv_lists *d; |
547 | ||
8b64056d OH |
548 | if (dev && dev->type != ARPHRD_CAN) |
549 | return; | |
550 | ||
8e8cda6d MK |
551 | if (dev && !net_eq(net, dev_net(dev))) |
552 | return; | |
0d66548a | 553 | |
8e8cda6d MK |
554 | spin_lock(&net->can.can_rcvlists_lock); |
555 | ||
556 | d = find_dev_rcv_lists(net, dev); | |
0d66548a | 557 | if (!d) { |
f4f3efda | 558 | pr_err("BUG: receive list not found for " |
0d66548a OH |
559 | "dev %s, id %03X, mask %03X\n", |
560 | DNAME(dev), can_id, mask); | |
561 | goto out; | |
562 | } | |
563 | ||
564 | rl = find_rcv_list(&can_id, &mask, d); | |
565 | ||
566 | /* | |
567 | * Search the receiver list for the item to delete. This should | |
568 | * exist, since no receiver may be unregistered that hasn't | |
569 | * been registered before. | |
570 | */ | |
571 | ||
b67bfe0d | 572 | hlist_for_each_entry_rcu(r, rl, list) { |
f64f9e71 JP |
573 | if (r->can_id == can_id && r->mask == mask && |
574 | r->func == func && r->data == data) | |
0d66548a OH |
575 | break; |
576 | } | |
577 | ||
578 | /* | |
c9bbb75f OH |
579 | * Check for bugs in CAN protocol implementations using af_can.c: |
580 | * 'r' will be NULL if no matching list item was found for removal. | |
0d66548a OH |
581 | */ |
582 | ||
b67bfe0d | 583 | if (!r) { |
c9bbb75f OH |
584 | WARN(1, "BUG: receive list entry not found for dev %s, " |
585 | "id %03X, mask %03X\n", DNAME(dev), can_id, mask); | |
0d66548a OH |
586 | goto out; |
587 | } | |
588 | ||
589 | hlist_del_rcu(&r->list); | |
590 | d->entries--; | |
591 | ||
592 | if (can_pstats.rcv_entries > 0) | |
593 | can_pstats.rcv_entries--; | |
594 | ||
595 | /* remove device structure requested by NETDEV_UNREGISTER */ | |
20dd3850 OH |
596 | if (d->remove_on_zero_entries && !d->entries) { |
597 | kfree(d); | |
598 | dev->ml_priv = NULL; | |
599 | } | |
0d66548a OH |
600 | |
601 | out: | |
8e8cda6d | 602 | spin_unlock(&net->can.can_rcvlists_lock); |
0d66548a OH |
603 | |
604 | /* schedule the receiver item for deletion */ | |
f1712c73 ED |
605 | if (r) { |
606 | if (r->sk) | |
607 | sock_hold(r->sk); | |
0d66548a | 608 | call_rcu(&r->rcu, can_rx_delete_receiver); |
f1712c73 | 609 | } |
0d66548a OH |
610 | } |
611 | EXPORT_SYMBOL(can_rx_unregister); | |
612 | ||
613 | static inline void deliver(struct sk_buff *skb, struct receiver *r) | |
614 | { | |
1fa17d4b OH |
615 | r->func(skb, r->data); |
616 | r->matches++; | |
0d66548a OH |
617 | } |
618 | ||
619 | static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) | |
620 | { | |
621 | struct receiver *r; | |
0d66548a OH |
622 | int matches = 0; |
623 | struct can_frame *cf = (struct can_frame *)skb->data; | |
624 | canid_t can_id = cf->can_id; | |
625 | ||
626 | if (d->entries == 0) | |
627 | return 0; | |
628 | ||
629 | if (can_id & CAN_ERR_FLAG) { | |
d6e640f9 | 630 | /* check for error message frame entries only */ |
b67bfe0d | 631 | hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) { |
0d66548a OH |
632 | if (can_id & r->mask) { |
633 | deliver(skb, r); | |
634 | matches++; | |
635 | } | |
636 | } | |
637 | return matches; | |
638 | } | |
639 | ||
640 | /* check for unfiltered entries */ | |
b67bfe0d | 641 | hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) { |
0d66548a OH |
642 | deliver(skb, r); |
643 | matches++; | |
644 | } | |
645 | ||
646 | /* check for can_id/mask entries */ | |
b67bfe0d | 647 | hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) { |
0d66548a OH |
648 | if ((can_id & r->mask) == r->can_id) { |
649 | deliver(skb, r); | |
650 | matches++; | |
651 | } | |
652 | } | |
653 | ||
654 | /* check for inverted can_id/mask entries */ | |
b67bfe0d | 655 | hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) { |
0d66548a OH |
656 | if ((can_id & r->mask) != r->can_id) { |
657 | deliver(skb, r); | |
658 | matches++; | |
659 | } | |
660 | } | |
661 | ||
f706644d OH |
662 | /* check filterlists for single non-RTR can_ids */ |
663 | if (can_id & CAN_RTR_FLAG) | |
664 | return matches; | |
665 | ||
0d66548a | 666 | if (can_id & CAN_EFF_FLAG) { |
45c70029 | 667 | hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) { |
0d66548a OH |
668 | if (r->can_id == can_id) { |
669 | deliver(skb, r); | |
670 | matches++; | |
671 | } | |
672 | } | |
673 | } else { | |
674 | can_id &= CAN_SFF_MASK; | |
b67bfe0d | 675 | hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) { |
0d66548a OH |
676 | deliver(skb, r); |
677 | matches++; | |
678 | } | |
679 | } | |
680 | ||
681 | return matches; | |
682 | } | |
683 | ||
8b01939f | 684 | static void can_receive(struct sk_buff *skb, struct net_device *dev) |
0d66548a OH |
685 | { |
686 | struct dev_rcv_lists *d; | |
687 | int matches; | |
688 | ||
0d66548a OH |
689 | /* update statistics */ |
690 | can_stats.rx_frames++; | |
691 | can_stats.rx_frames_delta++; | |
692 | ||
d3b58c47 OH |
693 | /* create non-zero unique skb identifier together with *skb */ |
694 | while (!(can_skb_prv(skb)->skbcnt)) | |
695 | can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter); | |
696 | ||
0d66548a OH |
697 | rcu_read_lock(); |
698 | ||
699 | /* deliver the packet to sockets listening on all devices */ | |
8e8cda6d | 700 | matches = can_rcv_filter(dev_net(dev)->can.can_rx_alldev_list, skb); |
0d66548a OH |
701 | |
702 | /* find receive list for this device */ | |
8e8cda6d | 703 | d = find_dev_rcv_lists(dev_net(dev), dev); |
0d66548a OH |
704 | if (d) |
705 | matches += can_rcv_filter(d, skb); | |
706 | ||
707 | rcu_read_unlock(); | |
708 | ||
62bcaa13 OH |
709 | /* consume the skbuff allocated by the netdevice driver */ |
710 | consume_skb(skb); | |
0d66548a OH |
711 | |
712 | if (matches > 0) { | |
713 | can_stats.matches++; | |
714 | can_stats.matches_delta++; | |
715 | } | |
8b01939f OH |
716 | } |
717 | ||
718 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
719 | struct packet_type *pt, struct net_device *orig_dev) | |
720 | { | |
721 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; | |
0d66548a | 722 | |
8b01939f OH |
723 | if (WARN_ONCE(dev->type != ARPHRD_CAN || |
724 | skb->len != CAN_MTU || | |
725 | cfd->len > CAN_MAX_DLEN, | |
726 | "PF_CAN: dropped non conform CAN skbuf: " | |
727 | "dev type %d, len %d, datalen %d\n", | |
728 | dev->type, skb->len, cfd->len)) | |
729 | goto drop; | |
730 | ||
731 | can_receive(skb, dev); | |
732 | return NET_RX_SUCCESS; | |
733 | ||
734 | drop: | |
735 | kfree_skb(skb); | |
736 | return NET_RX_DROP; | |
737 | } | |
738 | ||
739 | static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, | |
740 | struct packet_type *pt, struct net_device *orig_dev) | |
741 | { | |
742 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; | |
743 | ||
8b01939f OH |
744 | if (WARN_ONCE(dev->type != ARPHRD_CAN || |
745 | skb->len != CANFD_MTU || | |
746 | cfd->len > CANFD_MAX_DLEN, | |
747 | "PF_CAN: dropped non conform CAN FD skbuf: " | |
748 | "dev type %d, len %d, datalen %d\n", | |
749 | dev->type, skb->len, cfd->len)) | |
750 | goto drop; | |
751 | ||
752 | can_receive(skb, dev); | |
6ca8b990 | 753 | return NET_RX_SUCCESS; |
1758c094 OH |
754 | |
755 | drop: | |
756 | kfree_skb(skb); | |
6ca8b990 | 757 | return NET_RX_DROP; |
0d66548a OH |
758 | } |
759 | ||
760 | /* | |
761 | * af_can protocol functions | |
762 | */ | |
763 | ||
764 | /** | |
765 | * can_proto_register - register CAN transport protocol | |
766 | * @cp: pointer to CAN protocol structure | |
767 | * | |
768 | * Return: | |
769 | * 0 on success | |
770 | * -EINVAL invalid (out of range) protocol number | |
771 | * -EBUSY protocol already in use | |
772 | * -ENOBUF if proto_register() fails | |
773 | */ | |
1650629d | 774 | int can_proto_register(const struct can_proto *cp) |
0d66548a OH |
775 | { |
776 | int proto = cp->protocol; | |
777 | int err = 0; | |
778 | ||
779 | if (proto < 0 || proto >= CAN_NPROTO) { | |
f4f3efda | 780 | pr_err("can: protocol number %d out of range\n", proto); |
0d66548a OH |
781 | return -EINVAL; |
782 | } | |
783 | ||
a2fea5f1 UT |
784 | err = proto_register(cp->prot, 0); |
785 | if (err < 0) | |
786 | return err; | |
787 | ||
1ca050d9 OH |
788 | mutex_lock(&proto_tab_lock); |
789 | ||
0d66548a | 790 | if (proto_tab[proto]) { |
f4f3efda | 791 | pr_err("can: protocol %d already registered\n", proto); |
0d66548a | 792 | err = -EBUSY; |
53914b67 | 793 | } else |
a9b3cd7f | 794 | RCU_INIT_POINTER(proto_tab[proto], cp); |
a2fea5f1 | 795 | |
1ca050d9 | 796 | mutex_unlock(&proto_tab_lock); |
0d66548a | 797 | |
0d66548a | 798 | if (err < 0) |
a2fea5f1 | 799 | proto_unregister(cp->prot); |
0d66548a OH |
800 | |
801 | return err; | |
802 | } | |
803 | EXPORT_SYMBOL(can_proto_register); | |
804 | ||
805 | /** | |
806 | * can_proto_unregister - unregister CAN transport protocol | |
807 | * @cp: pointer to CAN protocol structure | |
808 | */ | |
1650629d | 809 | void can_proto_unregister(const struct can_proto *cp) |
0d66548a OH |
810 | { |
811 | int proto = cp->protocol; | |
812 | ||
1ca050d9 OH |
813 | mutex_lock(&proto_tab_lock); |
814 | BUG_ON(proto_tab[proto] != cp); | |
a9b3cd7f | 815 | RCU_INIT_POINTER(proto_tab[proto], NULL); |
1ca050d9 OH |
816 | mutex_unlock(&proto_tab_lock); |
817 | ||
818 | synchronize_rcu(); | |
a2fea5f1 UT |
819 | |
820 | proto_unregister(cp->prot); | |
0d66548a OH |
821 | } |
822 | EXPORT_SYMBOL(can_proto_unregister); | |
823 | ||
824 | /* | |
825 | * af_can notifier to create/remove CAN netdevice specific structs | |
826 | */ | |
827 | static int can_notifier(struct notifier_block *nb, unsigned long msg, | |
351638e7 | 828 | void *ptr) |
0d66548a | 829 | { |
351638e7 | 830 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
0d66548a OH |
831 | struct dev_rcv_lists *d; |
832 | ||
0d66548a OH |
833 | if (dev->type != ARPHRD_CAN) |
834 | return NOTIFY_DONE; | |
835 | ||
836 | switch (msg) { | |
837 | ||
838 | case NETDEV_REGISTER: | |
839 | ||
20dd3850 | 840 | /* create new dev_rcv_lists for this device */ |
0d66548a | 841 | d = kzalloc(sizeof(*d), GFP_KERNEL); |
f4f3efda | 842 | if (!d) |
0d66548a | 843 | return NOTIFY_DONE; |
20dd3850 OH |
844 | BUG_ON(dev->ml_priv); |
845 | dev->ml_priv = d; | |
0d66548a OH |
846 | |
847 | break; | |
848 | ||
849 | case NETDEV_UNREGISTER: | |
8e8cda6d | 850 | spin_lock(&dev_net(dev)->can.can_rcvlists_lock); |
0d66548a | 851 | |
20dd3850 | 852 | d = dev->ml_priv; |
0d66548a | 853 | if (d) { |
20dd3850 | 854 | if (d->entries) |
0d66548a | 855 | d->remove_on_zero_entries = 1; |
20dd3850 OH |
856 | else { |
857 | kfree(d); | |
858 | dev->ml_priv = NULL; | |
859 | } | |
0d66548a | 860 | } else |
f4f3efda VI |
861 | pr_err("can: notifier: receive list not found for dev " |
862 | "%s\n", dev->name); | |
0d66548a | 863 | |
8e8cda6d | 864 | spin_unlock(&dev_net(dev)->can.can_rcvlists_lock); |
0d66548a | 865 | |
0d66548a OH |
866 | break; |
867 | } | |
868 | ||
869 | return NOTIFY_DONE; | |
870 | } | |
871 | ||
8e8cda6d MK |
872 | static int can_pernet_init(struct net *net) |
873 | { | |
874 | net->can.can_rcvlists_lock = | |
875 | __SPIN_LOCK_UNLOCKED(net->can.can_rcvlists_lock); | |
876 | net->can.can_rx_alldev_list = | |
877 | kzalloc(sizeof(struct dev_rcv_lists), GFP_KERNEL); | |
878 | ||
879 | if (IS_ENABLED(CONFIG_PROC_FS)) | |
880 | can_init_proc(net); | |
881 | ||
882 | return 0; | |
883 | } | |
884 | ||
885 | static void can_pernet_exit(struct net *net) | |
886 | { | |
887 | struct net_device *dev; | |
888 | ||
889 | if (IS_ENABLED(CONFIG_PROC_FS)) | |
890 | can_remove_proc(net); | |
891 | ||
892 | /* remove created dev_rcv_lists from still registered CAN devices */ | |
893 | rcu_read_lock(); | |
894 | for_each_netdev_rcu(net, dev) { | |
895 | if (dev->type == ARPHRD_CAN && dev->ml_priv) { | |
896 | struct dev_rcv_lists *d = dev->ml_priv; | |
897 | ||
898 | BUG_ON(d->entries); | |
899 | kfree(d); | |
900 | dev->ml_priv = NULL; | |
901 | } | |
902 | } | |
903 | rcu_read_unlock(); | |
a7bbd28f OH |
904 | |
905 | kfree(net->can.can_rx_alldev_list); | |
8e8cda6d MK |
906 | } |
907 | ||
0d66548a OH |
908 | /* |
909 | * af_can module init/exit functions | |
910 | */ | |
911 | ||
912 | static struct packet_type can_packet __read_mostly = { | |
09640e63 | 913 | .type = cpu_to_be16(ETH_P_CAN), |
0d66548a OH |
914 | .func = can_rcv, |
915 | }; | |
916 | ||
8b01939f OH |
917 | static struct packet_type canfd_packet __read_mostly = { |
918 | .type = cpu_to_be16(ETH_P_CANFD), | |
919 | .func = canfd_rcv, | |
920 | }; | |
921 | ||
ec1b4cf7 | 922 | static const struct net_proto_family can_family_ops = { |
0d66548a OH |
923 | .family = PF_CAN, |
924 | .create = can_create, | |
925 | .owner = THIS_MODULE, | |
926 | }; | |
927 | ||
928 | /* notifier block for netdevice event */ | |
929 | static struct notifier_block can_netdev_notifier __read_mostly = { | |
930 | .notifier_call = can_notifier, | |
931 | }; | |
932 | ||
8e8cda6d MK |
933 | static struct pernet_operations can_pernet_ops __read_mostly = { |
934 | .init = can_pernet_init, | |
935 | .exit = can_pernet_exit, | |
8e8cda6d MK |
936 | }; |
937 | ||
0d66548a OH |
938 | static __init int can_init(void) |
939 | { | |
7c941636 OH |
940 | /* check for correct padding to be able to use the structs similarly */ |
941 | BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) != | |
942 | offsetof(struct canfd_frame, len) || | |
943 | offsetof(struct can_frame, data) != | |
944 | offsetof(struct canfd_frame, data)); | |
945 | ||
b111b78c | 946 | pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n"); |
0d66548a OH |
947 | |
948 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), | |
949 | 0, 0, NULL); | |
950 | if (!rcv_cache) | |
951 | return -ENOMEM; | |
952 | ||
2781ff5c AB |
953 | if (IS_ENABLED(CONFIG_PROC_FS)) { |
954 | if (stats_timer) { | |
0d66548a | 955 | /* the statistics are updated every second (timer triggered) */ |
2781ff5c AB |
956 | setup_timer(&can_stattimer, can_stat_update, 0); |
957 | mod_timer(&can_stattimer, round_jiffies(jiffies + HZ)); | |
958 | } | |
2781ff5c | 959 | } |
0d66548a | 960 | |
8e8cda6d MK |
961 | register_pernet_subsys(&can_pernet_ops); |
962 | ||
0d66548a OH |
963 | /* protocol register */ |
964 | sock_register(&can_family_ops); | |
965 | register_netdevice_notifier(&can_netdev_notifier); | |
966 | dev_add_pack(&can_packet); | |
8b01939f | 967 | dev_add_pack(&canfd_packet); |
0d66548a OH |
968 | |
969 | return 0; | |
970 | } | |
971 | ||
972 | static __exit void can_exit(void) | |
973 | { | |
2781ff5c AB |
974 | if (IS_ENABLED(CONFIG_PROC_FS)) { |
975 | if (stats_timer) | |
976 | del_timer_sync(&can_stattimer); | |
2781ff5c | 977 | } |
0d66548a OH |
978 | |
979 | /* protocol unregister */ | |
8b01939f | 980 | dev_remove_pack(&canfd_packet); |
0d66548a OH |
981 | dev_remove_pack(&can_packet); |
982 | unregister_netdevice_notifier(&can_netdev_notifier); | |
983 | sock_unregister(PF_CAN); | |
984 | ||
8e8cda6d | 985 | unregister_pernet_subsys(&can_pernet_ops); |
0d66548a | 986 | |
382bfeec JDB |
987 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
988 | ||
0d66548a OH |
989 | kmem_cache_destroy(rcv_cache); |
990 | } | |
991 | ||
992 | module_init(can_init); | |
993 | module_exit(can_exit); |