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fba76a58 | 1 | // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) |
147d9e9a | 2 | /* af_can.c - Protocol family CAN core module |
0d66548a OH |
3 | * (used by different CAN protocol modules) |
4 | * | |
cb5635a3 | 5 | * Copyright (c) 2002-2017 Volkswagen Group Electronic Research |
0d66548a OH |
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> |
ffd956ee | 61 | #include <linux/can/can-ml.h> |
d751e623 | 62 | #include <linux/ratelimit.h> |
0d66548a OH |
63 | #include <net/net_namespace.h> |
64 | #include <net/sock.h> | |
65 | ||
66 | #include "af_can.h" | |
67 | ||
0d66548a OH |
68 | MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); |
69 | MODULE_LICENSE("Dual BSD/GPL"); | |
70 | MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, " | |
71 | "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); | |
72 | ||
73 | MODULE_ALIAS_NETPROTO(PF_CAN); | |
74 | ||
75 | static int stats_timer __read_mostly = 1; | |
d6444062 | 76 | module_param(stats_timer, int, 0444); |
0d66548a OH |
77 | MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)"); |
78 | ||
0d66548a OH |
79 | static struct kmem_cache *rcv_cache __read_mostly; |
80 | ||
81 | /* table of registered CAN protocols */ | |
cae1d5b7 | 82 | static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly; |
1ca050d9 | 83 | static DEFINE_MUTEX(proto_tab_lock); |
0d66548a | 84 | |
d3b58c47 OH |
85 | static atomic_t skbcounter = ATOMIC_INIT(0); |
86 | ||
147d9e9a | 87 | /* af_can socket functions */ |
0d66548a | 88 | |
975987e7 | 89 | void can_sock_destruct(struct sock *sk) |
0d66548a OH |
90 | { |
91 | skb_queue_purge(&sk->sk_receive_queue); | |
fd704bd5 | 92 | skb_queue_purge(&sk->sk_error_queue); |
0d66548a | 93 | } |
975987e7 | 94 | EXPORT_SYMBOL(can_sock_destruct); |
0d66548a | 95 | |
c8d55a9d | 96 | static const struct can_proto *can_get_proto(int protocol) |
1ca050d9 | 97 | { |
1650629d | 98 | const struct can_proto *cp; |
1ca050d9 OH |
99 | |
100 | rcu_read_lock(); | |
101 | cp = rcu_dereference(proto_tab[protocol]); | |
102 | if (cp && !try_module_get(cp->prot->owner)) | |
103 | cp = NULL; | |
104 | rcu_read_unlock(); | |
105 | ||
106 | return cp; | |
107 | } | |
108 | ||
c8d55a9d KVD |
109 | static inline void can_put_proto(const struct can_proto *cp) |
110 | { | |
111 | module_put(cp->prot->owner); | |
112 | } | |
113 | ||
3f378b68 EP |
114 | static int can_create(struct net *net, struct socket *sock, int protocol, |
115 | int kern) | |
0d66548a OH |
116 | { |
117 | struct sock *sk; | |
1650629d | 118 | const struct can_proto *cp; |
0d66548a OH |
119 | int err = 0; |
120 | ||
121 | sock->state = SS_UNCONNECTED; | |
122 | ||
123 | if (protocol < 0 || protocol >= CAN_NPROTO) | |
124 | return -EINVAL; | |
125 | ||
c8d55a9d | 126 | cp = can_get_proto(protocol); |
1ca050d9 | 127 | |
95a5afca | 128 | #ifdef CONFIG_MODULES |
1ca050d9 OH |
129 | if (!cp) { |
130 | /* try to load protocol module if kernel is modular */ | |
131 | ||
5423dd67 | 132 | err = request_module("can-proto-%d", protocol); |
0d66548a | 133 | |
147d9e9a | 134 | /* In case of error we only print a message but don't |
0d66548a OH |
135 | * return the error code immediately. Below we will |
136 | * return -EPROTONOSUPPORT | |
137 | */ | |
d751e623 | 138 | if (err) |
1cf571eb MKB |
139 | pr_err_ratelimited("can: request_module (can-proto-%d) failed.\n", |
140 | protocol); | |
1ca050d9 | 141 | |
c8d55a9d | 142 | cp = can_get_proto(protocol); |
0d66548a | 143 | } |
5423dd67 | 144 | #endif |
0d66548a | 145 | |
0d66548a OH |
146 | /* check for available protocol and correct usage */ |
147 | ||
148 | if (!cp) | |
149 | return -EPROTONOSUPPORT; | |
150 | ||
151 | if (cp->type != sock->type) { | |
1ca050d9 | 152 | err = -EPROTOTYPE; |
0d66548a OH |
153 | goto errout; |
154 | } | |
155 | ||
0d66548a OH |
156 | sock->ops = cp->ops; |
157 | ||
11aa9c28 | 158 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern); |
0d66548a OH |
159 | if (!sk) { |
160 | err = -ENOMEM; | |
161 | goto errout; | |
162 | } | |
163 | ||
164 | sock_init_data(sock, sk); | |
165 | sk->sk_destruct = can_sock_destruct; | |
166 | ||
167 | if (sk->sk_prot->init) | |
168 | err = sk->sk_prot->init(sk); | |
169 | ||
170 | if (err) { | |
171 | /* release sk on errors */ | |
172 | sock_orphan(sk); | |
173 | sock_put(sk); | |
174 | } | |
175 | ||
176 | errout: | |
c8d55a9d | 177 | can_put_proto(cp); |
0d66548a OH |
178 | return err; |
179 | } | |
180 | ||
147d9e9a | 181 | /* af_can tx path */ |
0d66548a OH |
182 | |
183 | /** | |
184 | * can_send - transmit a CAN frame (optional with local loopback) | |
185 | * @skb: pointer to socket buffer with CAN frame in data section | |
186 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
187 | * | |
481a8199 OH |
188 | * Due to the loopback this routine must not be called from hardirq context. |
189 | * | |
0d66548a OH |
190 | * Return: |
191 | * 0 on success | |
192 | * -ENETDOWN when the selected interface is down | |
193 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
194 | * -ENOMEM when local loopback failed at calling skb_clone() | |
195 | * -EPERM when trying to send on a non-CAN interface | |
8b01939f | 196 | * -EMSGSIZE CAN frame size is bigger than CAN interface MTU |
7f2d38eb | 197 | * -EINVAL when the skb->data does not contain a valid CAN frame |
0d66548a OH |
198 | */ |
199 | int can_send(struct sk_buff *skb, int loop) | |
200 | { | |
c2ab7ac2 | 201 | struct sk_buff *newskb = NULL; |
8b01939f | 202 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; |
e2c1f5c7 | 203 | struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats; |
8b01939f OH |
204 | int err = -EINVAL; |
205 | ||
206 | if (skb->len == CAN_MTU) { | |
207 | skb->protocol = htons(ETH_P_CAN); | |
208 | if (unlikely(cfd->len > CAN_MAX_DLEN)) | |
209 | goto inval_skb; | |
210 | } else if (skb->len == CANFD_MTU) { | |
211 | skb->protocol = htons(ETH_P_CANFD); | |
212 | if (unlikely(cfd->len > CANFD_MAX_DLEN)) | |
213 | goto inval_skb; | |
8325ce9b | 214 | } else { |
8b01939f | 215 | goto inval_skb; |
8325ce9b | 216 | } |
0d66548a | 217 | |
147d9e9a | 218 | /* Make sure the CAN frame can pass the selected CAN netdevice. |
8b01939f OH |
219 | * As structs can_frame and canfd_frame are similar, we can provide |
220 | * CAN FD frames to legacy CAN drivers as long as the length is <= 8 | |
221 | */ | |
222 | if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) { | |
223 | err = -EMSGSIZE; | |
224 | goto inval_skb; | |
7f2d38eb OH |
225 | } |
226 | ||
8b01939f OH |
227 | if (unlikely(skb->dev->type != ARPHRD_CAN)) { |
228 | err = -EPERM; | |
229 | goto inval_skb; | |
0d66548a OH |
230 | } |
231 | ||
8b01939f OH |
232 | if (unlikely(!(skb->dev->flags & IFF_UP))) { |
233 | err = -ENETDOWN; | |
234 | goto inval_skb; | |
0d66548a OH |
235 | } |
236 | ||
96943901 OH |
237 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
238 | ||
239 | skb_reset_mac_header(skb); | |
0d66548a OH |
240 | skb_reset_network_header(skb); |
241 | skb_reset_transport_header(skb); | |
242 | ||
243 | if (loop) { | |
244 | /* local loopback of sent CAN frames */ | |
245 | ||
246 | /* indication for the CAN driver: do loopback */ | |
247 | skb->pkt_type = PACKET_LOOPBACK; | |
248 | ||
147d9e9a | 249 | /* The reference to the originating sock may be required |
0d66548a OH |
250 | * by the receiving socket to check whether the frame is |
251 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS | |
252 | * Therefore we have to ensure that skb->sk remains the | |
253 | * reference to the originating sock by restoring skb->sk | |
254 | * after each skb_clone() or skb_orphan() usage. | |
255 | */ | |
256 | ||
257 | if (!(skb->dev->flags & IFF_ECHO)) { | |
147d9e9a | 258 | /* If the interface is not capable to do loopback |
0d66548a OH |
259 | * itself, we do it here. |
260 | */ | |
c2ab7ac2 | 261 | newskb = skb_clone(skb, GFP_ATOMIC); |
0d66548a OH |
262 | if (!newskb) { |
263 | kfree_skb(skb); | |
264 | return -ENOMEM; | |
265 | } | |
266 | ||
0ae89beb | 267 | can_skb_set_owner(newskb, skb->sk); |
0d66548a OH |
268 | newskb->ip_summed = CHECKSUM_UNNECESSARY; |
269 | newskb->pkt_type = PACKET_BROADCAST; | |
0d66548a OH |
270 | } |
271 | } else { | |
272 | /* indication for the CAN driver: no loopback required */ | |
273 | skb->pkt_type = PACKET_HOST; | |
274 | } | |
275 | ||
276 | /* send to netdevice */ | |
277 | err = dev_queue_xmit(skb); | |
278 | if (err > 0) | |
279 | err = net_xmit_errno(err); | |
280 | ||
c2ab7ac2 | 281 | if (err) { |
ce030edf | 282 | kfree_skb(newskb); |
c2ab7ac2 OH |
283 | return err; |
284 | } | |
285 | ||
d3b58c47 | 286 | if (newskb) |
481a8199 | 287 | netif_rx_ni(newskb); |
c2ab7ac2 | 288 | |
0d66548a | 289 | /* update statistics */ |
e2c1f5c7 MKB |
290 | pkg_stats->tx_frames++; |
291 | pkg_stats->tx_frames_delta++; | |
0d66548a | 292 | |
c2ab7ac2 | 293 | return 0; |
8b01939f OH |
294 | |
295 | inval_skb: | |
296 | kfree_skb(skb); | |
297 | return err; | |
0d66548a OH |
298 | } |
299 | EXPORT_SYMBOL(can_send); | |
300 | ||
147d9e9a | 301 | /* af_can rx path */ |
0d66548a | 302 | |
fac78500 MKB |
303 | static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net, |
304 | struct net_device *dev) | |
0d66548a | 305 | { |
8df9ffb8 | 306 | if (dev) { |
8c51a3e9 OR |
307 | struct can_ml_priv *can_ml = can_get_ml_priv(dev); |
308 | return &can_ml->dev_rcv_lists; | |
8df9ffb8 | 309 | } else { |
564577df | 310 | return net->can.rx_alldev_list; |
8df9ffb8 | 311 | } |
0d66548a OH |
312 | } |
313 | ||
45c70029 OH |
314 | /** |
315 | * effhash - hash function for 29 bit CAN identifier reduction | |
316 | * @can_id: 29 bit CAN identifier | |
317 | * | |
318 | * Description: | |
319 | * To reduce the linear traversal in one linked list of _single_ EFF CAN | |
320 | * frame subscriptions the 29 bit identifier is mapped to 10 bits. | |
321 | * (see CAN_EFF_RCV_HASH_BITS definition) | |
322 | * | |
323 | * Return: | |
324 | * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask ) | |
325 | */ | |
326 | static unsigned int effhash(canid_t can_id) | |
327 | { | |
328 | unsigned int hash; | |
329 | ||
330 | hash = can_id; | |
331 | hash ^= can_id >> CAN_EFF_RCV_HASH_BITS; | |
332 | hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS); | |
333 | ||
334 | return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1); | |
335 | } | |
336 | ||
d253eee2 | 337 | /** |
3ee6d2be | 338 | * can_rcv_list_find - determine optimal filterlist inside device filter struct |
d253eee2 OH |
339 | * @can_id: pointer to CAN identifier of a given can_filter |
340 | * @mask: pointer to CAN mask of a given can_filter | |
341 | * @d: pointer to the device filter struct | |
342 | * | |
343 | * Description: | |
344 | * Returns the optimal filterlist to reduce the filter handling in the | |
345 | * receive path. This function is called by service functions that need | |
346 | * to register or unregister a can_filter in the filter lists. | |
347 | * | |
348 | * A filter matches in general, when | |
349 | * | |
350 | * <received_can_id> & mask == can_id & mask | |
351 | * | |
352 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe | |
353 | * relevant bits for the filter. | |
354 | * | |
355 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 OH |
356 | * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg |
357 | * frames there is a special filterlist and a special rx path filter handling. | |
d253eee2 OH |
358 | * |
359 | * Return: | |
360 | * Pointer to optimal filterlist for the given can_id/mask pair. | |
361 | * Constistency checked mask. | |
362 | * Reduced can_id to have a preprocessed filter compare value. | |
363 | */ | |
3ee6d2be MKB |
364 | static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask, |
365 | struct can_dev_rcv_lists *dev_rcv_lists) | |
0d66548a OH |
366 | { |
367 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
368 | ||
d6e640f9 | 369 | /* filter for error message frames in extra filterlist */ |
0d66548a | 370 | if (*mask & CAN_ERR_FLAG) { |
d253eee2 | 371 | /* clear CAN_ERR_FLAG in filter entry */ |
0d66548a | 372 | *mask &= CAN_ERR_MASK; |
56be1d52 | 373 | return &dev_rcv_lists->rx[RX_ERR]; |
0d66548a OH |
374 | } |
375 | ||
d253eee2 OH |
376 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
377 | ||
378 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) | |
379 | ||
380 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ | |
381 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) | |
382 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); | |
0d66548a OH |
383 | |
384 | /* reduce condition testing at receive time */ | |
385 | *can_id &= *mask; | |
386 | ||
387 | /* inverse can_id/can_mask filter */ | |
388 | if (inv) | |
56be1d52 | 389 | return &dev_rcv_lists->rx[RX_INV]; |
0d66548a OH |
390 | |
391 | /* mask == 0 => no condition testing at receive time */ | |
392 | if (!(*mask)) | |
56be1d52 | 393 | return &dev_rcv_lists->rx[RX_ALL]; |
0d66548a | 394 | |
d253eee2 | 395 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
f64f9e71 JP |
396 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) && |
397 | !(*can_id & CAN_RTR_FLAG)) { | |
d253eee2 | 398 | if (*can_id & CAN_EFF_FLAG) { |
45c70029 | 399 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) |
56be1d52 | 400 | return &dev_rcv_lists->rx_eff[effhash(*can_id)]; |
d253eee2 OH |
401 | } else { |
402 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) | |
56be1d52 | 403 | return &dev_rcv_lists->rx_sff[*can_id]; |
0d66548a | 404 | } |
0d66548a OH |
405 | } |
406 | ||
407 | /* default: filter via can_id/can_mask */ | |
56be1d52 | 408 | return &dev_rcv_lists->rx[RX_FIL]; |
0d66548a OH |
409 | } |
410 | ||
411 | /** | |
412 | * can_rx_register - subscribe CAN frames from a specific interface | |
413 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
414 | * @can_id: CAN identifier (see description) | |
415 | * @mask: CAN mask (see description) | |
416 | * @func: callback function on filter match | |
417 | * @data: returned parameter for callback function | |
3f79410c | 418 | * @ident: string for calling module identification |
f1712c73 | 419 | * @sk: socket pointer (might be NULL) |
0d66548a OH |
420 | * |
421 | * Description: | |
422 | * Invokes the callback function with the received sk_buff and the given | |
423 | * parameter 'data' on a matching receive filter. A filter matches, when | |
424 | * | |
425 | * <received_can_id> & mask == can_id & mask | |
426 | * | |
427 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 | 428 | * filter for error message frames (CAN_ERR_FLAG bit set in mask). |
0d66548a | 429 | * |
1fa17d4b OH |
430 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
431 | * the callback function is running. The callback function must *not* free | |
432 | * the given sk_buff while processing it's task. When the given sk_buff is | |
433 | * needed after the end of the callback function it must be cloned inside | |
434 | * the callback function with skb_clone(). | |
435 | * | |
0d66548a OH |
436 | * Return: |
437 | * 0 on success | |
438 | * -ENOMEM on missing cache mem to create subscription entry | |
439 | * -ENODEV unknown device | |
440 | */ | |
8e8cda6d MK |
441 | int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, |
442 | canid_t mask, void (*func)(struct sk_buff *, void *), | |
443 | void *data, char *ident, struct sock *sk) | |
0d66548a | 444 | { |
6625a18e MKB |
445 | struct receiver *rcv; |
446 | struct hlist_head *rcv_list; | |
56be1d52 | 447 | struct can_dev_rcv_lists *dev_rcv_lists; |
e2c1f5c7 | 448 | struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; |
0d66548a OH |
449 | int err = 0; |
450 | ||
451 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
452 | ||
8b64056d OH |
453 | if (dev && dev->type != ARPHRD_CAN) |
454 | return -ENODEV; | |
455 | ||
8e8cda6d MK |
456 | if (dev && !net_eq(net, dev_net(dev))) |
457 | return -ENODEV; | |
458 | ||
6625a18e MKB |
459 | rcv = kmem_cache_alloc(rcv_cache, GFP_KERNEL); |
460 | if (!rcv) | |
0d66548a OH |
461 | return -ENOMEM; |
462 | ||
24efc6d3 | 463 | spin_lock_bh(&net->can.rcvlists_lock); |
0d66548a | 464 | |
fac78500 | 465 | dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
bdfb5765 MKB |
466 | rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists); |
467 | ||
468 | rcv->can_id = can_id; | |
469 | rcv->mask = mask; | |
470 | rcv->matches = 0; | |
471 | rcv->func = func; | |
472 | rcv->data = data; | |
473 | rcv->ident = ident; | |
474 | rcv->sk = sk; | |
0d66548a | 475 | |
bdfb5765 MKB |
476 | hlist_add_head_rcu(&rcv->list, rcv_list); |
477 | dev_rcv_lists->entries++; | |
478 | ||
479 | rcv_lists_stats->rcv_entries++; | |
480 | rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max, | |
481 | rcv_lists_stats->rcv_entries); | |
24efc6d3 | 482 | spin_unlock_bh(&net->can.rcvlists_lock); |
0d66548a OH |
483 | |
484 | return err; | |
485 | } | |
486 | EXPORT_SYMBOL(can_rx_register); | |
487 | ||
147d9e9a | 488 | /* can_rx_delete_receiver - rcu callback for single receiver entry removal */ |
0d66548a OH |
489 | static void can_rx_delete_receiver(struct rcu_head *rp) |
490 | { | |
6625a18e MKB |
491 | struct receiver *rcv = container_of(rp, struct receiver, rcu); |
492 | struct sock *sk = rcv->sk; | |
0d66548a | 493 | |
6625a18e | 494 | kmem_cache_free(rcv_cache, rcv); |
f1712c73 ED |
495 | if (sk) |
496 | sock_put(sk); | |
0d66548a OH |
497 | } |
498 | ||
499 | /** | |
500 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
069f8457 | 501 | * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list) |
0d66548a OH |
502 | * @can_id: CAN identifier |
503 | * @mask: CAN mask | |
504 | * @func: callback function on filter match | |
505 | * @data: returned parameter for callback function | |
506 | * | |
507 | * Description: | |
508 | * Removes subscription entry depending on given (subscription) values. | |
509 | */ | |
8e8cda6d MK |
510 | void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id, |
511 | canid_t mask, void (*func)(struct sk_buff *, void *), | |
512 | void *data) | |
0d66548a | 513 | { |
6625a18e MKB |
514 | struct receiver *rcv = NULL; |
515 | struct hlist_head *rcv_list; | |
e2c1f5c7 | 516 | struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; |
56be1d52 | 517 | struct can_dev_rcv_lists *dev_rcv_lists; |
0d66548a | 518 | |
8b64056d OH |
519 | if (dev && dev->type != ARPHRD_CAN) |
520 | return; | |
521 | ||
8e8cda6d MK |
522 | if (dev && !net_eq(net, dev_net(dev))) |
523 | return; | |
0d66548a | 524 | |
24efc6d3 | 525 | spin_lock_bh(&net->can.rcvlists_lock); |
8e8cda6d | 526 | |
fac78500 | 527 | dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
6625a18e | 528 | rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists); |
0d66548a | 529 | |
147d9e9a | 530 | /* Search the receiver list for the item to delete. This should |
0d66548a OH |
531 | * exist, since no receiver may be unregistered that hasn't |
532 | * been registered before. | |
533 | */ | |
6625a18e MKB |
534 | hlist_for_each_entry_rcu(rcv, rcv_list, list) { |
535 | if (rcv->can_id == can_id && rcv->mask == mask && | |
536 | rcv->func == func && rcv->data == data) | |
0d66548a OH |
537 | break; |
538 | } | |
539 | ||
147d9e9a | 540 | /* Check for bugs in CAN protocol implementations using af_can.c: |
6625a18e | 541 | * 'rcv' will be NULL if no matching list item was found for removal. |
f0d585d0 OH |
542 | * As this case may potentially happen when closing a socket while |
543 | * the notifier for removing the CAN netdev is running we just print | |
544 | * a warning here. | |
0d66548a | 545 | */ |
6625a18e | 546 | if (!rcv) { |
f0d585d0 OH |
547 | pr_warn("can: receive list entry not found for dev %s, id %03X, mask %03X\n", |
548 | DNAME(dev), can_id, mask); | |
0d66548a OH |
549 | goto out; |
550 | } | |
551 | ||
6625a18e | 552 | hlist_del_rcu(&rcv->list); |
56be1d52 | 553 | dev_rcv_lists->entries--; |
0d66548a | 554 | |
e2c1f5c7 MKB |
555 | if (rcv_lists_stats->rcv_entries > 0) |
556 | rcv_lists_stats->rcv_entries--; | |
0d66548a | 557 | |
0d66548a | 558 | out: |
24efc6d3 | 559 | spin_unlock_bh(&net->can.rcvlists_lock); |
0d66548a OH |
560 | |
561 | /* schedule the receiver item for deletion */ | |
6625a18e MKB |
562 | if (rcv) { |
563 | if (rcv->sk) | |
564 | sock_hold(rcv->sk); | |
565 | call_rcu(&rcv->rcu, can_rx_delete_receiver); | |
f1712c73 | 566 | } |
0d66548a OH |
567 | } |
568 | EXPORT_SYMBOL(can_rx_unregister); | |
569 | ||
6625a18e | 570 | static inline void deliver(struct sk_buff *skb, struct receiver *rcv) |
0d66548a | 571 | { |
6625a18e MKB |
572 | rcv->func(skb, rcv->data); |
573 | rcv->matches++; | |
0d66548a OH |
574 | } |
575 | ||
56be1d52 | 576 | static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb) |
0d66548a | 577 | { |
6625a18e | 578 | struct receiver *rcv; |
0d66548a OH |
579 | int matches = 0; |
580 | struct can_frame *cf = (struct can_frame *)skb->data; | |
581 | canid_t can_id = cf->can_id; | |
582 | ||
56be1d52 | 583 | if (dev_rcv_lists->entries == 0) |
0d66548a OH |
584 | return 0; |
585 | ||
586 | if (can_id & CAN_ERR_FLAG) { | |
d6e640f9 | 587 | /* check for error message frame entries only */ |
6625a18e MKB |
588 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) { |
589 | if (can_id & rcv->mask) { | |
590 | deliver(skb, rcv); | |
0d66548a OH |
591 | matches++; |
592 | } | |
593 | } | |
594 | return matches; | |
595 | } | |
596 | ||
597 | /* check for unfiltered entries */ | |
6625a18e MKB |
598 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) { |
599 | deliver(skb, rcv); | |
0d66548a OH |
600 | matches++; |
601 | } | |
602 | ||
603 | /* check for can_id/mask entries */ | |
6625a18e MKB |
604 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) { |
605 | if ((can_id & rcv->mask) == rcv->can_id) { | |
606 | deliver(skb, rcv); | |
0d66548a OH |
607 | matches++; |
608 | } | |
609 | } | |
610 | ||
611 | /* check for inverted can_id/mask entries */ | |
6625a18e MKB |
612 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) { |
613 | if ((can_id & rcv->mask) != rcv->can_id) { | |
614 | deliver(skb, rcv); | |
0d66548a OH |
615 | matches++; |
616 | } | |
617 | } | |
618 | ||
f706644d OH |
619 | /* check filterlists for single non-RTR can_ids */ |
620 | if (can_id & CAN_RTR_FLAG) | |
621 | return matches; | |
622 | ||
0d66548a | 623 | if (can_id & CAN_EFF_FLAG) { |
6625a18e MKB |
624 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) { |
625 | if (rcv->can_id == can_id) { | |
626 | deliver(skb, rcv); | |
0d66548a OH |
627 | matches++; |
628 | } | |
629 | } | |
630 | } else { | |
631 | can_id &= CAN_SFF_MASK; | |
6625a18e MKB |
632 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) { |
633 | deliver(skb, rcv); | |
0d66548a OH |
634 | matches++; |
635 | } | |
636 | } | |
637 | ||
638 | return matches; | |
639 | } | |
640 | ||
8b01939f | 641 | static void can_receive(struct sk_buff *skb, struct net_device *dev) |
0d66548a | 642 | { |
56be1d52 | 643 | struct can_dev_rcv_lists *dev_rcv_lists; |
cb5635a3 | 644 | struct net *net = dev_net(dev); |
e2c1f5c7 | 645 | struct can_pkg_stats *pkg_stats = net->can.pkg_stats; |
0d66548a OH |
646 | int matches; |
647 | ||
0d66548a | 648 | /* update statistics */ |
e2c1f5c7 MKB |
649 | pkg_stats->rx_frames++; |
650 | pkg_stats->rx_frames_delta++; | |
0d66548a | 651 | |
d3b58c47 OH |
652 | /* create non-zero unique skb identifier together with *skb */ |
653 | while (!(can_skb_prv(skb)->skbcnt)) | |
654 | can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter); | |
655 | ||
0d66548a OH |
656 | rcu_read_lock(); |
657 | ||
658 | /* deliver the packet to sockets listening on all devices */ | |
564577df | 659 | matches = can_rcv_filter(net->can.rx_alldev_list, skb); |
0d66548a OH |
660 | |
661 | /* find receive list for this device */ | |
fac78500 | 662 | dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
bdfb5765 | 663 | matches += can_rcv_filter(dev_rcv_lists, skb); |
0d66548a OH |
664 | |
665 | rcu_read_unlock(); | |
666 | ||
62bcaa13 OH |
667 | /* consume the skbuff allocated by the netdevice driver */ |
668 | consume_skb(skb); | |
0d66548a OH |
669 | |
670 | if (matches > 0) { | |
e2c1f5c7 MKB |
671 | pkg_stats->matches++; |
672 | pkg_stats->matches_delta++; | |
0d66548a | 673 | } |
8b01939f OH |
674 | } |
675 | ||
676 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
677 | struct packet_type *pt, struct net_device *orig_dev) | |
678 | { | |
679 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; | |
0d66548a | 680 | |
275bae57 AT |
681 | if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) { |
682 | pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n", | |
683 | dev->type, skb->len); | |
684 | goto free_skb; | |
685 | } | |
686 | ||
687 | /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */ | |
688 | if (unlikely(cfd->len > CAN_MAX_DLEN)) { | |
689 | pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d, datalen %d\n", | |
8cb68751 | 690 | dev->type, skb->len, cfd->len); |
275bae57 | 691 | goto free_skb; |
8cb68751 | 692 | } |
8b01939f OH |
693 | |
694 | can_receive(skb, dev); | |
695 | return NET_RX_SUCCESS; | |
275bae57 AT |
696 | |
697 | free_skb: | |
698 | kfree_skb(skb); | |
699 | return NET_RX_DROP; | |
8b01939f OH |
700 | } |
701 | ||
702 | static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, | |
b11844b6 | 703 | struct packet_type *pt, struct net_device *orig_dev) |
8b01939f OH |
704 | { |
705 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; | |
706 | ||
17a4ae02 AT |
707 | if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) { |
708 | pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n", | |
709 | dev->type, skb->len); | |
710 | goto free_skb; | |
711 | } | |
712 | ||
713 | /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */ | |
714 | if (unlikely(cfd->len > CANFD_MAX_DLEN)) { | |
715 | pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d, datalen %d\n", | |
d4689846 | 716 | dev->type, skb->len, cfd->len); |
17a4ae02 | 717 | goto free_skb; |
d4689846 | 718 | } |
8b01939f OH |
719 | |
720 | can_receive(skb, dev); | |
6ca8b990 | 721 | return NET_RX_SUCCESS; |
17a4ae02 AT |
722 | |
723 | free_skb: | |
724 | kfree_skb(skb); | |
725 | return NET_RX_DROP; | |
0d66548a OH |
726 | } |
727 | ||
147d9e9a | 728 | /* af_can protocol functions */ |
0d66548a OH |
729 | |
730 | /** | |
731 | * can_proto_register - register CAN transport protocol | |
732 | * @cp: pointer to CAN protocol structure | |
733 | * | |
734 | * Return: | |
735 | * 0 on success | |
736 | * -EINVAL invalid (out of range) protocol number | |
737 | * -EBUSY protocol already in use | |
738 | * -ENOBUF if proto_register() fails | |
739 | */ | |
1650629d | 740 | int can_proto_register(const struct can_proto *cp) |
0d66548a OH |
741 | { |
742 | int proto = cp->protocol; | |
743 | int err = 0; | |
744 | ||
745 | if (proto < 0 || proto >= CAN_NPROTO) { | |
f4f3efda | 746 | pr_err("can: protocol number %d out of range\n", proto); |
0d66548a OH |
747 | return -EINVAL; |
748 | } | |
749 | ||
a2fea5f1 UT |
750 | err = proto_register(cp->prot, 0); |
751 | if (err < 0) | |
752 | return err; | |
753 | ||
1ca050d9 OH |
754 | mutex_lock(&proto_tab_lock); |
755 | ||
cae1d5b7 | 756 | if (rcu_access_pointer(proto_tab[proto])) { |
f4f3efda | 757 | pr_err("can: protocol %d already registered\n", proto); |
0d66548a | 758 | err = -EBUSY; |
8325ce9b | 759 | } else { |
a9b3cd7f | 760 | RCU_INIT_POINTER(proto_tab[proto], cp); |
8325ce9b | 761 | } |
a2fea5f1 | 762 | |
1ca050d9 | 763 | mutex_unlock(&proto_tab_lock); |
0d66548a | 764 | |
0d66548a | 765 | if (err < 0) |
a2fea5f1 | 766 | proto_unregister(cp->prot); |
0d66548a OH |
767 | |
768 | return err; | |
769 | } | |
770 | EXPORT_SYMBOL(can_proto_register); | |
771 | ||
772 | /** | |
773 | * can_proto_unregister - unregister CAN transport protocol | |
774 | * @cp: pointer to CAN protocol structure | |
775 | */ | |
1650629d | 776 | void can_proto_unregister(const struct can_proto *cp) |
0d66548a OH |
777 | { |
778 | int proto = cp->protocol; | |
779 | ||
1ca050d9 | 780 | mutex_lock(&proto_tab_lock); |
cae1d5b7 | 781 | BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp); |
a9b3cd7f | 782 | RCU_INIT_POINTER(proto_tab[proto], NULL); |
1ca050d9 OH |
783 | mutex_unlock(&proto_tab_lock); |
784 | ||
785 | synchronize_rcu(); | |
a2fea5f1 UT |
786 | |
787 | proto_unregister(cp->prot); | |
0d66548a OH |
788 | } |
789 | EXPORT_SYMBOL(can_proto_unregister); | |
790 | ||
8e8cda6d MK |
791 | static int can_pernet_init(struct net *net) |
792 | { | |
564577df MKB |
793 | spin_lock_init(&net->can.rcvlists_lock); |
794 | net->can.rx_alldev_list = | |
795 | kzalloc(sizeof(*net->can.rx_alldev_list), GFP_KERNEL); | |
796 | if (!net->can.rx_alldev_list) | |
5a606223 | 797 | goto out; |
2341086d MKB |
798 | net->can.pkg_stats = kzalloc(sizeof(*net->can.pkg_stats), GFP_KERNEL); |
799 | if (!net->can.pkg_stats) | |
800 | goto out_free_rx_alldev_list; | |
801 | net->can.rcv_lists_stats = kzalloc(sizeof(*net->can.rcv_lists_stats), GFP_KERNEL); | |
802 | if (!net->can.rcv_lists_stats) | |
803 | goto out_free_pkg_stats; | |
cb5635a3 OH |
804 | |
805 | if (IS_ENABLED(CONFIG_PROC_FS)) { | |
806 | /* the statistics are updated every second (timer triggered) */ | |
807 | if (stats_timer) { | |
564577df | 808 | timer_setup(&net->can.stattimer, can_stat_update, |
1fccb565 | 809 | 0); |
564577df | 810 | mod_timer(&net->can.stattimer, |
cb5635a3 OH |
811 | round_jiffies(jiffies + HZ)); |
812 | } | |
2341086d | 813 | net->can.pkg_stats->jiffies_init = jiffies; |
8e8cda6d | 814 | can_init_proc(net); |
cb5635a3 | 815 | } |
8e8cda6d MK |
816 | |
817 | return 0; | |
5a606223 | 818 | |
2341086d MKB |
819 | out_free_pkg_stats: |
820 | kfree(net->can.pkg_stats); | |
821 | out_free_rx_alldev_list: | |
564577df | 822 | kfree(net->can.rx_alldev_list); |
5a606223 MKB |
823 | out: |
824 | return -ENOMEM; | |
8e8cda6d MK |
825 | } |
826 | ||
827 | static void can_pernet_exit(struct net *net) | |
828 | { | |
cb5635a3 | 829 | if (IS_ENABLED(CONFIG_PROC_FS)) { |
8e8cda6d | 830 | can_remove_proc(net); |
cb5635a3 | 831 | if (stats_timer) |
564577df | 832 | del_timer_sync(&net->can.stattimer); |
cb5635a3 | 833 | } |
8e8cda6d | 834 | |
564577df | 835 | kfree(net->can.rx_alldev_list); |
2341086d MKB |
836 | kfree(net->can.pkg_stats); |
837 | kfree(net->can.rcv_lists_stats); | |
8e8cda6d MK |
838 | } |
839 | ||
147d9e9a | 840 | /* af_can module init/exit functions */ |
0d66548a OH |
841 | |
842 | static struct packet_type can_packet __read_mostly = { | |
09640e63 | 843 | .type = cpu_to_be16(ETH_P_CAN), |
0d66548a OH |
844 | .func = can_rcv, |
845 | }; | |
846 | ||
8b01939f OH |
847 | static struct packet_type canfd_packet __read_mostly = { |
848 | .type = cpu_to_be16(ETH_P_CANFD), | |
849 | .func = canfd_rcv, | |
850 | }; | |
851 | ||
ec1b4cf7 | 852 | static const struct net_proto_family can_family_ops = { |
0d66548a OH |
853 | .family = PF_CAN, |
854 | .create = can_create, | |
855 | .owner = THIS_MODULE, | |
856 | }; | |
857 | ||
8e8cda6d MK |
858 | static struct pernet_operations can_pernet_ops __read_mostly = { |
859 | .init = can_pernet_init, | |
860 | .exit = can_pernet_exit, | |
8e8cda6d MK |
861 | }; |
862 | ||
0d66548a OH |
863 | static __init int can_init(void) |
864 | { | |
c5a3aed1 Y |
865 | int err; |
866 | ||
7c941636 OH |
867 | /* check for correct padding to be able to use the structs similarly */ |
868 | BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) != | |
869 | offsetof(struct canfd_frame, len) || | |
870 | offsetof(struct can_frame, data) != | |
871 | offsetof(struct canfd_frame, data)); | |
872 | ||
b111b78c | 873 | pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n"); |
0d66548a OH |
874 | |
875 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), | |
876 | 0, 0, NULL); | |
877 | if (!rcv_cache) | |
878 | return -ENOMEM; | |
879 | ||
c5a3aed1 Y |
880 | err = register_pernet_subsys(&can_pernet_ops); |
881 | if (err) | |
882 | goto out_pernet; | |
8e8cda6d | 883 | |
0d66548a | 884 | /* protocol register */ |
c5a3aed1 Y |
885 | err = sock_register(&can_family_ops); |
886 | if (err) | |
887 | goto out_sock; | |
c5a3aed1 | 888 | |
0d66548a | 889 | dev_add_pack(&can_packet); |
8b01939f | 890 | dev_add_pack(&canfd_packet); |
0d66548a OH |
891 | |
892 | return 0; | |
c5a3aed1 | 893 | |
c5a3aed1 Y |
894 | out_sock: |
895 | unregister_pernet_subsys(&can_pernet_ops); | |
896 | out_pernet: | |
897 | kmem_cache_destroy(rcv_cache); | |
898 | ||
899 | return err; | |
0d66548a OH |
900 | } |
901 | ||
902 | static __exit void can_exit(void) | |
903 | { | |
0d66548a | 904 | /* protocol unregister */ |
8b01939f | 905 | dev_remove_pack(&canfd_packet); |
0d66548a | 906 | dev_remove_pack(&can_packet); |
0d66548a OH |
907 | sock_unregister(PF_CAN); |
908 | ||
8e8cda6d | 909 | unregister_pernet_subsys(&can_pernet_ops); |
0d66548a | 910 | |
382bfeec JDB |
911 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
912 | ||
0d66548a OH |
913 | kmem_cache_destroy(rcv_cache); |
914 | } | |
915 | ||
916 | module_init(can_init); | |
917 | module_exit(can_exit); |