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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 | |
0d66548a OH |
89 | static void can_sock_destruct(struct sock *sk) |
90 | { | |
91 | skb_queue_purge(&sk->sk_receive_queue); | |
fd704bd5 | 92 | skb_queue_purge(&sk->sk_error_queue); |
0d66548a OH |
93 | } |
94 | ||
c8d55a9d | 95 | static const struct can_proto *can_get_proto(int protocol) |
1ca050d9 | 96 | { |
1650629d | 97 | const struct can_proto *cp; |
1ca050d9 OH |
98 | |
99 | rcu_read_lock(); | |
100 | cp = rcu_dereference(proto_tab[protocol]); | |
101 | if (cp && !try_module_get(cp->prot->owner)) | |
102 | cp = NULL; | |
103 | rcu_read_unlock(); | |
104 | ||
105 | return cp; | |
106 | } | |
107 | ||
c8d55a9d KVD |
108 | static inline void can_put_proto(const struct can_proto *cp) |
109 | { | |
110 | module_put(cp->prot->owner); | |
111 | } | |
112 | ||
3f378b68 EP |
113 | static int can_create(struct net *net, struct socket *sock, int protocol, |
114 | int kern) | |
0d66548a OH |
115 | { |
116 | struct sock *sk; | |
1650629d | 117 | const struct can_proto *cp; |
0d66548a OH |
118 | int err = 0; |
119 | ||
120 | sock->state = SS_UNCONNECTED; | |
121 | ||
122 | if (protocol < 0 || protocol >= CAN_NPROTO) | |
123 | return -EINVAL; | |
124 | ||
c8d55a9d | 125 | cp = can_get_proto(protocol); |
1ca050d9 | 126 | |
95a5afca | 127 | #ifdef CONFIG_MODULES |
1ca050d9 OH |
128 | if (!cp) { |
129 | /* try to load protocol module if kernel is modular */ | |
130 | ||
5423dd67 | 131 | err = request_module("can-proto-%d", protocol); |
0d66548a | 132 | |
147d9e9a | 133 | /* In case of error we only print a message but don't |
0d66548a OH |
134 | * return the error code immediately. Below we will |
135 | * return -EPROTONOSUPPORT | |
136 | */ | |
d751e623 | 137 | if (err) |
1cf571eb MKB |
138 | pr_err_ratelimited("can: request_module (can-proto-%d) failed.\n", |
139 | protocol); | |
1ca050d9 | 140 | |
c8d55a9d | 141 | cp = can_get_proto(protocol); |
0d66548a | 142 | } |
5423dd67 | 143 | #endif |
0d66548a | 144 | |
0d66548a OH |
145 | /* check for available protocol and correct usage */ |
146 | ||
147 | if (!cp) | |
148 | return -EPROTONOSUPPORT; | |
149 | ||
150 | if (cp->type != sock->type) { | |
1ca050d9 | 151 | err = -EPROTOTYPE; |
0d66548a OH |
152 | goto errout; |
153 | } | |
154 | ||
0d66548a OH |
155 | sock->ops = cp->ops; |
156 | ||
11aa9c28 | 157 | sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern); |
0d66548a OH |
158 | if (!sk) { |
159 | err = -ENOMEM; | |
160 | goto errout; | |
161 | } | |
162 | ||
163 | sock_init_data(sock, sk); | |
164 | sk->sk_destruct = can_sock_destruct; | |
165 | ||
166 | if (sk->sk_prot->init) | |
167 | err = sk->sk_prot->init(sk); | |
168 | ||
169 | if (err) { | |
170 | /* release sk on errors */ | |
171 | sock_orphan(sk); | |
172 | sock_put(sk); | |
173 | } | |
174 | ||
175 | errout: | |
c8d55a9d | 176 | can_put_proto(cp); |
0d66548a OH |
177 | return err; |
178 | } | |
179 | ||
147d9e9a | 180 | /* af_can tx path */ |
0d66548a OH |
181 | |
182 | /** | |
183 | * can_send - transmit a CAN frame (optional with local loopback) | |
184 | * @skb: pointer to socket buffer with CAN frame in data section | |
185 | * @loop: loopback for listeners on local CAN sockets (recommended default!) | |
186 | * | |
481a8199 OH |
187 | * Due to the loopback this routine must not be called from hardirq context. |
188 | * | |
0d66548a OH |
189 | * Return: |
190 | * 0 on success | |
191 | * -ENETDOWN when the selected interface is down | |
192 | * -ENOBUFS on full driver queue (see net_xmit_errno()) | |
193 | * -ENOMEM when local loopback failed at calling skb_clone() | |
194 | * -EPERM when trying to send on a non-CAN interface | |
8b01939f | 195 | * -EMSGSIZE CAN frame size is bigger than CAN interface MTU |
7f2d38eb | 196 | * -EINVAL when the skb->data does not contain a valid CAN frame |
0d66548a OH |
197 | */ |
198 | int can_send(struct sk_buff *skb, int loop) | |
199 | { | |
c2ab7ac2 | 200 | struct sk_buff *newskb = NULL; |
8b01939f | 201 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; |
e2c1f5c7 | 202 | struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats; |
8b01939f OH |
203 | int err = -EINVAL; |
204 | ||
205 | if (skb->len == CAN_MTU) { | |
206 | skb->protocol = htons(ETH_P_CAN); | |
207 | if (unlikely(cfd->len > CAN_MAX_DLEN)) | |
208 | goto inval_skb; | |
209 | } else if (skb->len == CANFD_MTU) { | |
210 | skb->protocol = htons(ETH_P_CANFD); | |
211 | if (unlikely(cfd->len > CANFD_MAX_DLEN)) | |
212 | goto inval_skb; | |
8325ce9b | 213 | } else { |
8b01939f | 214 | goto inval_skb; |
8325ce9b | 215 | } |
0d66548a | 216 | |
147d9e9a | 217 | /* Make sure the CAN frame can pass the selected CAN netdevice. |
8b01939f OH |
218 | * As structs can_frame and canfd_frame are similar, we can provide |
219 | * CAN FD frames to legacy CAN drivers as long as the length is <= 8 | |
220 | */ | |
221 | if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) { | |
222 | err = -EMSGSIZE; | |
223 | goto inval_skb; | |
7f2d38eb OH |
224 | } |
225 | ||
8b01939f OH |
226 | if (unlikely(skb->dev->type != ARPHRD_CAN)) { |
227 | err = -EPERM; | |
228 | goto inval_skb; | |
0d66548a OH |
229 | } |
230 | ||
8b01939f OH |
231 | if (unlikely(!(skb->dev->flags & IFF_UP))) { |
232 | err = -ENETDOWN; | |
233 | goto inval_skb; | |
0d66548a OH |
234 | } |
235 | ||
96943901 OH |
236 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
237 | ||
238 | skb_reset_mac_header(skb); | |
0d66548a OH |
239 | skb_reset_network_header(skb); |
240 | skb_reset_transport_header(skb); | |
241 | ||
242 | if (loop) { | |
243 | /* local loopback of sent CAN frames */ | |
244 | ||
245 | /* indication for the CAN driver: do loopback */ | |
246 | skb->pkt_type = PACKET_LOOPBACK; | |
247 | ||
147d9e9a | 248 | /* The reference to the originating sock may be required |
0d66548a OH |
249 | * by the receiving socket to check whether the frame is |
250 | * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS | |
251 | * Therefore we have to ensure that skb->sk remains the | |
252 | * reference to the originating sock by restoring skb->sk | |
253 | * after each skb_clone() or skb_orphan() usage. | |
254 | */ | |
255 | ||
256 | if (!(skb->dev->flags & IFF_ECHO)) { | |
147d9e9a | 257 | /* If the interface is not capable to do loopback |
0d66548a OH |
258 | * itself, we do it here. |
259 | */ | |
c2ab7ac2 | 260 | newskb = skb_clone(skb, GFP_ATOMIC); |
0d66548a OH |
261 | if (!newskb) { |
262 | kfree_skb(skb); | |
263 | return -ENOMEM; | |
264 | } | |
265 | ||
0ae89beb | 266 | can_skb_set_owner(newskb, skb->sk); |
0d66548a OH |
267 | newskb->ip_summed = CHECKSUM_UNNECESSARY; |
268 | newskb->pkt_type = PACKET_BROADCAST; | |
0d66548a OH |
269 | } |
270 | } else { | |
271 | /* indication for the CAN driver: no loopback required */ | |
272 | skb->pkt_type = PACKET_HOST; | |
273 | } | |
274 | ||
275 | /* send to netdevice */ | |
276 | err = dev_queue_xmit(skb); | |
277 | if (err > 0) | |
278 | err = net_xmit_errno(err); | |
279 | ||
c2ab7ac2 | 280 | if (err) { |
ce030edf | 281 | kfree_skb(newskb); |
c2ab7ac2 OH |
282 | return err; |
283 | } | |
284 | ||
d3b58c47 | 285 | if (newskb) |
481a8199 | 286 | netif_rx_ni(newskb); |
c2ab7ac2 | 287 | |
0d66548a | 288 | /* update statistics */ |
e2c1f5c7 MKB |
289 | pkg_stats->tx_frames++; |
290 | pkg_stats->tx_frames_delta++; | |
0d66548a | 291 | |
c2ab7ac2 | 292 | return 0; |
8b01939f OH |
293 | |
294 | inval_skb: | |
295 | kfree_skb(skb); | |
296 | return err; | |
0d66548a OH |
297 | } |
298 | EXPORT_SYMBOL(can_send); | |
299 | ||
147d9e9a | 300 | /* af_can rx path */ |
0d66548a | 301 | |
fac78500 MKB |
302 | static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net, |
303 | struct net_device *dev) | |
0d66548a | 304 | { |
8df9ffb8 MKB |
305 | if (dev) { |
306 | struct can_ml_priv *ml_priv = dev->ml_priv; | |
307 | return &ml_priv->dev_rcv_lists; | |
308 | } else { | |
564577df | 309 | return net->can.rx_alldev_list; |
8df9ffb8 | 310 | } |
0d66548a OH |
311 | } |
312 | ||
45c70029 OH |
313 | /** |
314 | * effhash - hash function for 29 bit CAN identifier reduction | |
315 | * @can_id: 29 bit CAN identifier | |
316 | * | |
317 | * Description: | |
318 | * To reduce the linear traversal in one linked list of _single_ EFF CAN | |
319 | * frame subscriptions the 29 bit identifier is mapped to 10 bits. | |
320 | * (see CAN_EFF_RCV_HASH_BITS definition) | |
321 | * | |
322 | * Return: | |
323 | * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask ) | |
324 | */ | |
325 | static unsigned int effhash(canid_t can_id) | |
326 | { | |
327 | unsigned int hash; | |
328 | ||
329 | hash = can_id; | |
330 | hash ^= can_id >> CAN_EFF_RCV_HASH_BITS; | |
331 | hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS); | |
332 | ||
333 | return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1); | |
334 | } | |
335 | ||
d253eee2 | 336 | /** |
3ee6d2be | 337 | * can_rcv_list_find - determine optimal filterlist inside device filter struct |
d253eee2 OH |
338 | * @can_id: pointer to CAN identifier of a given can_filter |
339 | * @mask: pointer to CAN mask of a given can_filter | |
340 | * @d: pointer to the device filter struct | |
341 | * | |
342 | * Description: | |
343 | * Returns the optimal filterlist to reduce the filter handling in the | |
344 | * receive path. This function is called by service functions that need | |
345 | * to register or unregister a can_filter in the filter lists. | |
346 | * | |
347 | * A filter matches in general, when | |
348 | * | |
349 | * <received_can_id> & mask == can_id & mask | |
350 | * | |
351 | * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe | |
352 | * relevant bits for the filter. | |
353 | * | |
354 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 OH |
355 | * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg |
356 | * frames there is a special filterlist and a special rx path filter handling. | |
d253eee2 OH |
357 | * |
358 | * Return: | |
359 | * Pointer to optimal filterlist for the given can_id/mask pair. | |
360 | * Constistency checked mask. | |
361 | * Reduced can_id to have a preprocessed filter compare value. | |
362 | */ | |
3ee6d2be MKB |
363 | static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask, |
364 | struct can_dev_rcv_lists *dev_rcv_lists) | |
0d66548a OH |
365 | { |
366 | canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ | |
367 | ||
d6e640f9 | 368 | /* filter for error message frames in extra filterlist */ |
0d66548a | 369 | if (*mask & CAN_ERR_FLAG) { |
d253eee2 | 370 | /* clear CAN_ERR_FLAG in filter entry */ |
0d66548a | 371 | *mask &= CAN_ERR_MASK; |
56be1d52 | 372 | return &dev_rcv_lists->rx[RX_ERR]; |
0d66548a OH |
373 | } |
374 | ||
d253eee2 OH |
375 | /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ |
376 | ||
377 | #define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) | |
378 | ||
379 | /* ensure valid values in can_mask for 'SFF only' frame filtering */ | |
380 | if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) | |
381 | *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); | |
0d66548a OH |
382 | |
383 | /* reduce condition testing at receive time */ | |
384 | *can_id &= *mask; | |
385 | ||
386 | /* inverse can_id/can_mask filter */ | |
387 | if (inv) | |
56be1d52 | 388 | return &dev_rcv_lists->rx[RX_INV]; |
0d66548a OH |
389 | |
390 | /* mask == 0 => no condition testing at receive time */ | |
391 | if (!(*mask)) | |
56be1d52 | 392 | return &dev_rcv_lists->rx[RX_ALL]; |
0d66548a | 393 | |
d253eee2 | 394 | /* extra filterlists for the subscription of a single non-RTR can_id */ |
f64f9e71 JP |
395 | if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) && |
396 | !(*can_id & CAN_RTR_FLAG)) { | |
d253eee2 | 397 | if (*can_id & CAN_EFF_FLAG) { |
45c70029 | 398 | if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) |
56be1d52 | 399 | return &dev_rcv_lists->rx_eff[effhash(*can_id)]; |
d253eee2 OH |
400 | } else { |
401 | if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) | |
56be1d52 | 402 | return &dev_rcv_lists->rx_sff[*can_id]; |
0d66548a | 403 | } |
0d66548a OH |
404 | } |
405 | ||
406 | /* default: filter via can_id/can_mask */ | |
56be1d52 | 407 | return &dev_rcv_lists->rx[RX_FIL]; |
0d66548a OH |
408 | } |
409 | ||
410 | /** | |
411 | * can_rx_register - subscribe CAN frames from a specific interface | |
412 | * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list) | |
413 | * @can_id: CAN identifier (see description) | |
414 | * @mask: CAN mask (see description) | |
415 | * @func: callback function on filter match | |
416 | * @data: returned parameter for callback function | |
3f79410c | 417 | * @ident: string for calling module identification |
f1712c73 | 418 | * @sk: socket pointer (might be NULL) |
0d66548a OH |
419 | * |
420 | * Description: | |
421 | * Invokes the callback function with the received sk_buff and the given | |
422 | * parameter 'data' on a matching receive filter. A filter matches, when | |
423 | * | |
424 | * <received_can_id> & mask == can_id & mask | |
425 | * | |
426 | * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can | |
d6e640f9 | 427 | * filter for error message frames (CAN_ERR_FLAG bit set in mask). |
0d66548a | 428 | * |
1fa17d4b OH |
429 | * The provided pointer to the sk_buff is guaranteed to be valid as long as |
430 | * the callback function is running. The callback function must *not* free | |
431 | * the given sk_buff while processing it's task. When the given sk_buff is | |
432 | * needed after the end of the callback function it must be cloned inside | |
433 | * the callback function with skb_clone(). | |
434 | * | |
0d66548a OH |
435 | * Return: |
436 | * 0 on success | |
437 | * -ENOMEM on missing cache mem to create subscription entry | |
438 | * -ENODEV unknown device | |
439 | */ | |
8e8cda6d MK |
440 | int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id, |
441 | canid_t mask, void (*func)(struct sk_buff *, void *), | |
442 | void *data, char *ident, struct sock *sk) | |
0d66548a | 443 | { |
6625a18e MKB |
444 | struct receiver *rcv; |
445 | struct hlist_head *rcv_list; | |
56be1d52 | 446 | struct can_dev_rcv_lists *dev_rcv_lists; |
e2c1f5c7 | 447 | struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; |
0d66548a OH |
448 | int err = 0; |
449 | ||
450 | /* insert new receiver (dev,canid,mask) -> (func,data) */ | |
451 | ||
8b64056d OH |
452 | if (dev && dev->type != ARPHRD_CAN) |
453 | return -ENODEV; | |
454 | ||
8e8cda6d MK |
455 | if (dev && !net_eq(net, dev_net(dev))) |
456 | return -ENODEV; | |
457 | ||
6625a18e MKB |
458 | rcv = kmem_cache_alloc(rcv_cache, GFP_KERNEL); |
459 | if (!rcv) | |
0d66548a OH |
460 | return -ENOMEM; |
461 | ||
564577df | 462 | spin_lock(&net->can.rcvlists_lock); |
0d66548a | 463 | |
fac78500 | 464 | dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
56be1d52 | 465 | if (dev_rcv_lists) { |
6625a18e | 466 | rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists); |
0d66548a | 467 | |
6625a18e MKB |
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 | |
6625a18e | 476 | hlist_add_head_rcu(&rcv->list, rcv_list); |
56be1d52 | 477 | dev_rcv_lists->entries++; |
0d66548a | 478 | |
e2c1f5c7 | 479 | rcv_lists_stats->rcv_entries++; |
e2586a57 MKB |
480 | rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max, |
481 | rcv_lists_stats->rcv_entries); | |
0d66548a | 482 | } else { |
6625a18e | 483 | kmem_cache_free(rcv_cache, rcv); |
0d66548a OH |
484 | err = -ENODEV; |
485 | } | |
486 | ||
564577df | 487 | spin_unlock(&net->can.rcvlists_lock); |
0d66548a OH |
488 | |
489 | return err; | |
490 | } | |
491 | EXPORT_SYMBOL(can_rx_register); | |
492 | ||
147d9e9a | 493 | /* can_rx_delete_receiver - rcu callback for single receiver entry removal */ |
0d66548a OH |
494 | static void can_rx_delete_receiver(struct rcu_head *rp) |
495 | { | |
6625a18e MKB |
496 | struct receiver *rcv = container_of(rp, struct receiver, rcu); |
497 | struct sock *sk = rcv->sk; | |
0d66548a | 498 | |
6625a18e | 499 | kmem_cache_free(rcv_cache, rcv); |
f1712c73 ED |
500 | if (sk) |
501 | sock_put(sk); | |
0d66548a OH |
502 | } |
503 | ||
504 | /** | |
505 | * can_rx_unregister - unsubscribe CAN frames from a specific interface | |
069f8457 | 506 | * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list) |
0d66548a OH |
507 | * @can_id: CAN identifier |
508 | * @mask: CAN mask | |
509 | * @func: callback function on filter match | |
510 | * @data: returned parameter for callback function | |
511 | * | |
512 | * Description: | |
513 | * Removes subscription entry depending on given (subscription) values. | |
514 | */ | |
8e8cda6d MK |
515 | void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id, |
516 | canid_t mask, void (*func)(struct sk_buff *, void *), | |
517 | void *data) | |
0d66548a | 518 | { |
6625a18e MKB |
519 | struct receiver *rcv = NULL; |
520 | struct hlist_head *rcv_list; | |
e2c1f5c7 | 521 | struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats; |
56be1d52 | 522 | struct can_dev_rcv_lists *dev_rcv_lists; |
0d66548a | 523 | |
8b64056d OH |
524 | if (dev && dev->type != ARPHRD_CAN) |
525 | return; | |
526 | ||
8e8cda6d MK |
527 | if (dev && !net_eq(net, dev_net(dev))) |
528 | return; | |
0d66548a | 529 | |
564577df | 530 | spin_lock(&net->can.rcvlists_lock); |
8e8cda6d | 531 | |
fac78500 | 532 | dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
56be1d52 | 533 | if (!dev_rcv_lists) { |
1cf571eb | 534 | pr_err("BUG: receive list not found for dev %s, id %03X, mask %03X\n", |
0d66548a OH |
535 | DNAME(dev), can_id, mask); |
536 | goto out; | |
537 | } | |
538 | ||
6625a18e | 539 | rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists); |
0d66548a | 540 | |
147d9e9a | 541 | /* Search the receiver list for the item to delete. This should |
0d66548a OH |
542 | * exist, since no receiver may be unregistered that hasn't |
543 | * been registered before. | |
544 | */ | |
6625a18e MKB |
545 | hlist_for_each_entry_rcu(rcv, rcv_list, list) { |
546 | if (rcv->can_id == can_id && rcv->mask == mask && | |
547 | rcv->func == func && rcv->data == data) | |
0d66548a OH |
548 | break; |
549 | } | |
550 | ||
147d9e9a | 551 | /* Check for bugs in CAN protocol implementations using af_can.c: |
6625a18e | 552 | * 'rcv' will be NULL if no matching list item was found for removal. |
0d66548a | 553 | */ |
6625a18e | 554 | if (!rcv) { |
1cf571eb MKB |
555 | WARN(1, "BUG: receive list entry not found for dev %s, id %03X, mask %03X\n", |
556 | DNAME(dev), can_id, mask); | |
0d66548a OH |
557 | goto out; |
558 | } | |
559 | ||
6625a18e | 560 | hlist_del_rcu(&rcv->list); |
56be1d52 | 561 | dev_rcv_lists->entries--; |
0d66548a | 562 | |
e2c1f5c7 MKB |
563 | if (rcv_lists_stats->rcv_entries > 0) |
564 | rcv_lists_stats->rcv_entries--; | |
0d66548a | 565 | |
0d66548a | 566 | out: |
564577df | 567 | spin_unlock(&net->can.rcvlists_lock); |
0d66548a OH |
568 | |
569 | /* schedule the receiver item for deletion */ | |
6625a18e MKB |
570 | if (rcv) { |
571 | if (rcv->sk) | |
572 | sock_hold(rcv->sk); | |
573 | call_rcu(&rcv->rcu, can_rx_delete_receiver); | |
f1712c73 | 574 | } |
0d66548a OH |
575 | } |
576 | EXPORT_SYMBOL(can_rx_unregister); | |
577 | ||
6625a18e | 578 | static inline void deliver(struct sk_buff *skb, struct receiver *rcv) |
0d66548a | 579 | { |
6625a18e MKB |
580 | rcv->func(skb, rcv->data); |
581 | rcv->matches++; | |
0d66548a OH |
582 | } |
583 | ||
56be1d52 | 584 | static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb) |
0d66548a | 585 | { |
6625a18e | 586 | struct receiver *rcv; |
0d66548a OH |
587 | int matches = 0; |
588 | struct can_frame *cf = (struct can_frame *)skb->data; | |
589 | canid_t can_id = cf->can_id; | |
590 | ||
56be1d52 | 591 | if (dev_rcv_lists->entries == 0) |
0d66548a OH |
592 | return 0; |
593 | ||
594 | if (can_id & CAN_ERR_FLAG) { | |
d6e640f9 | 595 | /* check for error message frame entries only */ |
6625a18e MKB |
596 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) { |
597 | if (can_id & rcv->mask) { | |
598 | deliver(skb, rcv); | |
0d66548a OH |
599 | matches++; |
600 | } | |
601 | } | |
602 | return matches; | |
603 | } | |
604 | ||
605 | /* check for unfiltered entries */ | |
6625a18e MKB |
606 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) { |
607 | deliver(skb, rcv); | |
0d66548a OH |
608 | matches++; |
609 | } | |
610 | ||
611 | /* check for can_id/mask entries */ | |
6625a18e MKB |
612 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) { |
613 | if ((can_id & rcv->mask) == rcv->can_id) { | |
614 | deliver(skb, rcv); | |
0d66548a OH |
615 | matches++; |
616 | } | |
617 | } | |
618 | ||
619 | /* check for inverted can_id/mask entries */ | |
6625a18e MKB |
620 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) { |
621 | if ((can_id & rcv->mask) != rcv->can_id) { | |
622 | deliver(skb, rcv); | |
0d66548a OH |
623 | matches++; |
624 | } | |
625 | } | |
626 | ||
f706644d OH |
627 | /* check filterlists for single non-RTR can_ids */ |
628 | if (can_id & CAN_RTR_FLAG) | |
629 | return matches; | |
630 | ||
0d66548a | 631 | if (can_id & CAN_EFF_FLAG) { |
6625a18e MKB |
632 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) { |
633 | if (rcv->can_id == can_id) { | |
634 | deliver(skb, rcv); | |
0d66548a OH |
635 | matches++; |
636 | } | |
637 | } | |
638 | } else { | |
639 | can_id &= CAN_SFF_MASK; | |
6625a18e MKB |
640 | hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) { |
641 | deliver(skb, rcv); | |
0d66548a OH |
642 | matches++; |
643 | } | |
644 | } | |
645 | ||
646 | return matches; | |
647 | } | |
648 | ||
8b01939f | 649 | static void can_receive(struct sk_buff *skb, struct net_device *dev) |
0d66548a | 650 | { |
56be1d52 | 651 | struct can_dev_rcv_lists *dev_rcv_lists; |
cb5635a3 | 652 | struct net *net = dev_net(dev); |
e2c1f5c7 | 653 | struct can_pkg_stats *pkg_stats = net->can.pkg_stats; |
0d66548a OH |
654 | int matches; |
655 | ||
0d66548a | 656 | /* update statistics */ |
e2c1f5c7 MKB |
657 | pkg_stats->rx_frames++; |
658 | pkg_stats->rx_frames_delta++; | |
0d66548a | 659 | |
d3b58c47 OH |
660 | /* create non-zero unique skb identifier together with *skb */ |
661 | while (!(can_skb_prv(skb)->skbcnt)) | |
662 | can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter); | |
663 | ||
0d66548a OH |
664 | rcu_read_lock(); |
665 | ||
666 | /* deliver the packet to sockets listening on all devices */ | |
564577df | 667 | matches = can_rcv_filter(net->can.rx_alldev_list, skb); |
0d66548a OH |
668 | |
669 | /* find receive list for this device */ | |
fac78500 | 670 | dev_rcv_lists = can_dev_rcv_lists_find(net, dev); |
56be1d52 MKB |
671 | if (dev_rcv_lists) |
672 | matches += can_rcv_filter(dev_rcv_lists, skb); | |
0d66548a OH |
673 | |
674 | rcu_read_unlock(); | |
675 | ||
62bcaa13 OH |
676 | /* consume the skbuff allocated by the netdevice driver */ |
677 | consume_skb(skb); | |
0d66548a OH |
678 | |
679 | if (matches > 0) { | |
e2c1f5c7 MKB |
680 | pkg_stats->matches++; |
681 | pkg_stats->matches_delta++; | |
0d66548a | 682 | } |
8b01939f OH |
683 | } |
684 | ||
685 | static int can_rcv(struct sk_buff *skb, struct net_device *dev, | |
686 | struct packet_type *pt, struct net_device *orig_dev) | |
687 | { | |
688 | struct canfd_frame *cfd = (struct canfd_frame *)skb->data; | |
0d66548a | 689 | |
8cb68751 MKB |
690 | if (unlikely(dev->type != ARPHRD_CAN || skb->len != CAN_MTU || |
691 | cfd->len > CAN_MAX_DLEN)) { | |
692 | pr_warn_once("PF_CAN: dropped non conform CAN skbuf: dev type %d, len %d, datalen %d\n", | |
693 | dev->type, skb->len, cfd->len); | |
694 | kfree_skb(skb); | |
695 | return NET_RX_DROP; | |
696 | } | |
8b01939f OH |
697 | |
698 | can_receive(skb, dev); | |
699 | return NET_RX_SUCCESS; | |
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 | ||
d4689846 MKB |
707 | if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU || |
708 | cfd->len > CANFD_MAX_DLEN)) { | |
709 | pr_warn_once("PF_CAN: dropped non conform CAN FD skbuf: dev type %d, len %d, datalen %d\n", | |
710 | dev->type, skb->len, cfd->len); | |
711 | kfree_skb(skb); | |
712 | return NET_RX_DROP; | |
713 | } | |
8b01939f OH |
714 | |
715 | can_receive(skb, dev); | |
6ca8b990 | 716 | return NET_RX_SUCCESS; |
0d66548a OH |
717 | } |
718 | ||
147d9e9a | 719 | /* af_can protocol functions */ |
0d66548a OH |
720 | |
721 | /** | |
722 | * can_proto_register - register CAN transport protocol | |
723 | * @cp: pointer to CAN protocol structure | |
724 | * | |
725 | * Return: | |
726 | * 0 on success | |
727 | * -EINVAL invalid (out of range) protocol number | |
728 | * -EBUSY protocol already in use | |
729 | * -ENOBUF if proto_register() fails | |
730 | */ | |
1650629d | 731 | int can_proto_register(const struct can_proto *cp) |
0d66548a OH |
732 | { |
733 | int proto = cp->protocol; | |
734 | int err = 0; | |
735 | ||
736 | if (proto < 0 || proto >= CAN_NPROTO) { | |
f4f3efda | 737 | pr_err("can: protocol number %d out of range\n", proto); |
0d66548a OH |
738 | return -EINVAL; |
739 | } | |
740 | ||
a2fea5f1 UT |
741 | err = proto_register(cp->prot, 0); |
742 | if (err < 0) | |
743 | return err; | |
744 | ||
1ca050d9 OH |
745 | mutex_lock(&proto_tab_lock); |
746 | ||
cae1d5b7 | 747 | if (rcu_access_pointer(proto_tab[proto])) { |
f4f3efda | 748 | pr_err("can: protocol %d already registered\n", proto); |
0d66548a | 749 | err = -EBUSY; |
8325ce9b | 750 | } else { |
a9b3cd7f | 751 | RCU_INIT_POINTER(proto_tab[proto], cp); |
8325ce9b | 752 | } |
a2fea5f1 | 753 | |
1ca050d9 | 754 | mutex_unlock(&proto_tab_lock); |
0d66548a | 755 | |
0d66548a | 756 | if (err < 0) |
a2fea5f1 | 757 | proto_unregister(cp->prot); |
0d66548a OH |
758 | |
759 | return err; | |
760 | } | |
761 | EXPORT_SYMBOL(can_proto_register); | |
762 | ||
763 | /** | |
764 | * can_proto_unregister - unregister CAN transport protocol | |
765 | * @cp: pointer to CAN protocol structure | |
766 | */ | |
1650629d | 767 | void can_proto_unregister(const struct can_proto *cp) |
0d66548a OH |
768 | { |
769 | int proto = cp->protocol; | |
770 | ||
1ca050d9 | 771 | mutex_lock(&proto_tab_lock); |
cae1d5b7 | 772 | BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp); |
a9b3cd7f | 773 | RCU_INIT_POINTER(proto_tab[proto], NULL); |
1ca050d9 OH |
774 | mutex_unlock(&proto_tab_lock); |
775 | ||
776 | synchronize_rcu(); | |
a2fea5f1 UT |
777 | |
778 | proto_unregister(cp->prot); | |
0d66548a OH |
779 | } |
780 | EXPORT_SYMBOL(can_proto_unregister); | |
781 | ||
147d9e9a | 782 | /* af_can notifier to create/remove CAN netdevice specific structs */ |
0d66548a | 783 | static int can_notifier(struct notifier_block *nb, unsigned long msg, |
351638e7 | 784 | void *ptr) |
0d66548a | 785 | { |
351638e7 | 786 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
0d66548a | 787 | |
0d66548a OH |
788 | if (dev->type != ARPHRD_CAN) |
789 | return NOTIFY_DONE; | |
790 | ||
791 | switch (msg) { | |
0d66548a | 792 | case NETDEV_REGISTER: |
8df9ffb8 MKB |
793 | WARN(!dev->ml_priv, |
794 | "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n"); | |
0d66548a OH |
795 | break; |
796 | } | |
797 | ||
798 | return NOTIFY_DONE; | |
799 | } | |
800 | ||
8e8cda6d MK |
801 | static int can_pernet_init(struct net *net) |
802 | { | |
564577df MKB |
803 | spin_lock_init(&net->can.rcvlists_lock); |
804 | net->can.rx_alldev_list = | |
805 | kzalloc(sizeof(*net->can.rx_alldev_list), GFP_KERNEL); | |
806 | if (!net->can.rx_alldev_list) | |
5a606223 | 807 | goto out; |
2341086d MKB |
808 | net->can.pkg_stats = kzalloc(sizeof(*net->can.pkg_stats), GFP_KERNEL); |
809 | if (!net->can.pkg_stats) | |
810 | goto out_free_rx_alldev_list; | |
811 | net->can.rcv_lists_stats = kzalloc(sizeof(*net->can.rcv_lists_stats), GFP_KERNEL); | |
812 | if (!net->can.rcv_lists_stats) | |
813 | goto out_free_pkg_stats; | |
cb5635a3 OH |
814 | |
815 | if (IS_ENABLED(CONFIG_PROC_FS)) { | |
816 | /* the statistics are updated every second (timer triggered) */ | |
817 | if (stats_timer) { | |
564577df | 818 | timer_setup(&net->can.stattimer, can_stat_update, |
1fccb565 | 819 | 0); |
564577df | 820 | mod_timer(&net->can.stattimer, |
cb5635a3 OH |
821 | round_jiffies(jiffies + HZ)); |
822 | } | |
2341086d | 823 | net->can.pkg_stats->jiffies_init = jiffies; |
8e8cda6d | 824 | can_init_proc(net); |
cb5635a3 | 825 | } |
8e8cda6d MK |
826 | |
827 | return 0; | |
5a606223 | 828 | |
2341086d MKB |
829 | out_free_pkg_stats: |
830 | kfree(net->can.pkg_stats); | |
831 | out_free_rx_alldev_list: | |
564577df | 832 | kfree(net->can.rx_alldev_list); |
5a606223 MKB |
833 | out: |
834 | return -ENOMEM; | |
8e8cda6d MK |
835 | } |
836 | ||
837 | static void can_pernet_exit(struct net *net) | |
838 | { | |
cb5635a3 | 839 | if (IS_ENABLED(CONFIG_PROC_FS)) { |
8e8cda6d | 840 | can_remove_proc(net); |
cb5635a3 | 841 | if (stats_timer) |
564577df | 842 | del_timer_sync(&net->can.stattimer); |
cb5635a3 | 843 | } |
8e8cda6d | 844 | |
564577df | 845 | kfree(net->can.rx_alldev_list); |
2341086d MKB |
846 | kfree(net->can.pkg_stats); |
847 | kfree(net->can.rcv_lists_stats); | |
8e8cda6d MK |
848 | } |
849 | ||
147d9e9a | 850 | /* af_can module init/exit functions */ |
0d66548a OH |
851 | |
852 | static struct packet_type can_packet __read_mostly = { | |
09640e63 | 853 | .type = cpu_to_be16(ETH_P_CAN), |
0d66548a OH |
854 | .func = can_rcv, |
855 | }; | |
856 | ||
8b01939f OH |
857 | static struct packet_type canfd_packet __read_mostly = { |
858 | .type = cpu_to_be16(ETH_P_CANFD), | |
859 | .func = canfd_rcv, | |
860 | }; | |
861 | ||
ec1b4cf7 | 862 | static const struct net_proto_family can_family_ops = { |
0d66548a OH |
863 | .family = PF_CAN, |
864 | .create = can_create, | |
865 | .owner = THIS_MODULE, | |
866 | }; | |
867 | ||
868 | /* notifier block for netdevice event */ | |
869 | static struct notifier_block can_netdev_notifier __read_mostly = { | |
870 | .notifier_call = can_notifier, | |
871 | }; | |
872 | ||
8e8cda6d MK |
873 | static struct pernet_operations can_pernet_ops __read_mostly = { |
874 | .init = can_pernet_init, | |
875 | .exit = can_pernet_exit, | |
8e8cda6d MK |
876 | }; |
877 | ||
0d66548a OH |
878 | static __init int can_init(void) |
879 | { | |
c5a3aed1 Y |
880 | int err; |
881 | ||
7c941636 OH |
882 | /* check for correct padding to be able to use the structs similarly */ |
883 | BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) != | |
884 | offsetof(struct canfd_frame, len) || | |
885 | offsetof(struct can_frame, data) != | |
886 | offsetof(struct canfd_frame, data)); | |
887 | ||
b111b78c | 888 | pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n"); |
0d66548a OH |
889 | |
890 | rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver), | |
891 | 0, 0, NULL); | |
892 | if (!rcv_cache) | |
893 | return -ENOMEM; | |
894 | ||
c5a3aed1 Y |
895 | err = register_pernet_subsys(&can_pernet_ops); |
896 | if (err) | |
897 | goto out_pernet; | |
8e8cda6d | 898 | |
0d66548a | 899 | /* protocol register */ |
c5a3aed1 Y |
900 | err = sock_register(&can_family_ops); |
901 | if (err) | |
902 | goto out_sock; | |
903 | err = register_netdevice_notifier(&can_netdev_notifier); | |
904 | if (err) | |
905 | goto out_notifier; | |
906 | ||
0d66548a | 907 | dev_add_pack(&can_packet); |
8b01939f | 908 | dev_add_pack(&canfd_packet); |
0d66548a OH |
909 | |
910 | return 0; | |
c5a3aed1 Y |
911 | |
912 | out_notifier: | |
913 | sock_unregister(PF_CAN); | |
914 | out_sock: | |
915 | unregister_pernet_subsys(&can_pernet_ops); | |
916 | out_pernet: | |
917 | kmem_cache_destroy(rcv_cache); | |
918 | ||
919 | return err; | |
0d66548a OH |
920 | } |
921 | ||
922 | static __exit void can_exit(void) | |
923 | { | |
0d66548a | 924 | /* protocol unregister */ |
8b01939f | 925 | dev_remove_pack(&canfd_packet); |
0d66548a OH |
926 | dev_remove_pack(&can_packet); |
927 | unregister_netdevice_notifier(&can_netdev_notifier); | |
928 | sock_unregister(PF_CAN); | |
929 | ||
8e8cda6d | 930 | unregister_pernet_subsys(&can_pernet_ops); |
0d66548a | 931 | |
382bfeec JDB |
932 | rcu_barrier(); /* Wait for completion of call_rcu()'s */ |
933 | ||
0d66548a OH |
934 | kmem_cache_destroy(rcv_cache); |
935 | } | |
936 | ||
937 | module_init(can_init); | |
938 | module_exit(can_exit); |