blob: 821022a7214f544090eb8504bce180484bf0d79e [file] [log] [blame]
Oliver Hartkopp0d665482007-11-16 15:52:17 -08001/*
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 *
Oliver Hartkopp0d665482007-11-16 15:52:17 -080041 */
42
43#include <linux/module.h>
Oliver Hartkopp7c941632012-06-13 20:04:33 +020044#include <linux/stddef.h>
Oliver Hartkopp0d665482007-11-16 15:52:17 -080045#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>
Manuel Zerpiesd751e622011-06-16 02:08:01 +000060#include <linux/ratelimit.h>
Oliver Hartkopp0d665482007-11-16 15:52:17 -080061#include <net/net_namespace.h>
62#include <net/sock.h>
63
64#include "af_can.h"
65
66static __initdata const char banner[] = KERN_INFO
67 "can: controller area network core (" CAN_VERSION_STRING ")\n";
68
69MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
70MODULE_LICENSE("Dual BSD/GPL");
71MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
72 "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
73
74MODULE_ALIAS_NETPROTO(PF_CAN);
75
76static int stats_timer __read_mostly = 1;
77module_param(stats_timer, int, S_IRUGO);
78MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
79
Oliver Hartkopp20dd3852009-12-25 06:47:47 +000080/* receive filters subscribed for 'all' CAN devices */
81struct dev_rcv_lists can_rx_alldev_list;
Oliver Hartkopp0d665482007-11-16 15:52:17 -080082static DEFINE_SPINLOCK(can_rcvlists_lock);
83
84static struct kmem_cache *rcv_cache __read_mostly;
85
86/* table of registered CAN protocols */
Kurt Van Dijck16506292011-05-03 18:40:57 +000087static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +000088static DEFINE_MUTEX(proto_tab_lock);
Oliver Hartkopp0d665482007-11-16 15:52:17 -080089
90struct timer_list can_stattimer; /* timer for statistics update */
91struct s_stats can_stats; /* packet statistics */
92struct s_pstats can_pstats; /* receive list statistics */
93
94/*
95 * af_can socket functions
96 */
97
Oliver Hartkopp53914b62011-03-22 08:27:25 +000098int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
Oliver Hartkopp0d665482007-11-16 15:52:17 -080099{
100 struct sock *sk = sock->sk;
101
102 switch (cmd) {
103
104 case SIOCGSTAMP:
105 return sock_get_timestamp(sk, (struct timeval __user *)arg);
106
107 default:
108 return -ENOIOCTLCMD;
109 }
110}
Oliver Hartkopp53914b62011-03-22 08:27:25 +0000111EXPORT_SYMBOL(can_ioctl);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800112
113static void can_sock_destruct(struct sock *sk)
114{
115 skb_queue_purge(&sk->sk_receive_queue);
116}
117
Kurt Van Dijckc8d55a92011-05-03 18:42:04 +0000118static const struct can_proto *can_get_proto(int protocol)
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000119{
Kurt Van Dijck16506292011-05-03 18:40:57 +0000120 const struct can_proto *cp;
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000121
122 rcu_read_lock();
123 cp = rcu_dereference(proto_tab[protocol]);
124 if (cp && !try_module_get(cp->prot->owner))
125 cp = NULL;
126 rcu_read_unlock();
127
128 return cp;
129}
130
Kurt Van Dijckc8d55a92011-05-03 18:42:04 +0000131static inline void can_put_proto(const struct can_proto *cp)
132{
133 module_put(cp->prot->owner);
134}
135
Eric Paris3f378b62009-11-05 22:18:14 -0800136static int can_create(struct net *net, struct socket *sock, int protocol,
137 int kern)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800138{
139 struct sock *sk;
Kurt Van Dijck16506292011-05-03 18:40:57 +0000140 const struct can_proto *cp;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800141 int err = 0;
142
143 sock->state = SS_UNCONNECTED;
144
145 if (protocol < 0 || protocol >= CAN_NPROTO)
146 return -EINVAL;
147
Octavian Purdila09ad9bc2009-11-25 15:14:13 -0800148 if (!net_eq(net, &init_net))
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800149 return -EAFNOSUPPORT;
150
Kurt Van Dijckc8d55a92011-05-03 18:42:04 +0000151 cp = can_get_proto(protocol);
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000152
Johannes Berg95a5afc2008-10-16 15:24:51 -0700153#ifdef CONFIG_MODULES
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000154 if (!cp) {
155 /* try to load protocol module if kernel is modular */
156
Urs Thuermann5423dd62008-02-07 18:04:21 -0800157 err = request_module("can-proto-%d", protocol);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800158
159 /*
160 * In case of error we only print a message but don't
161 * return the error code immediately. Below we will
162 * return -EPROTONOSUPPORT
163 */
Manuel Zerpiesd751e622011-06-16 02:08:01 +0000164 if (err)
165 printk_ratelimited(KERN_ERR "can: request_module "
Urs Thuermann5423dd62008-02-07 18:04:21 -0800166 "(can-proto-%d) failed.\n", protocol);
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000167
Kurt Van Dijckc8d55a92011-05-03 18:42:04 +0000168 cp = can_get_proto(protocol);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800169 }
Urs Thuermann5423dd62008-02-07 18:04:21 -0800170#endif
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800171
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800172 /* check for available protocol and correct usage */
173
174 if (!cp)
175 return -EPROTONOSUPPORT;
176
177 if (cp->type != sock->type) {
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000178 err = -EPROTOTYPE;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800179 goto errout;
180 }
181
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800182 sock->ops = cp->ops;
183
184 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot);
185 if (!sk) {
186 err = -ENOMEM;
187 goto errout;
188 }
189
190 sock_init_data(sock, sk);
191 sk->sk_destruct = can_sock_destruct;
192
193 if (sk->sk_prot->init)
194 err = sk->sk_prot->init(sk);
195
196 if (err) {
197 /* release sk on errors */
198 sock_orphan(sk);
199 sock_put(sk);
200 }
201
202 errout:
Kurt Van Dijckc8d55a92011-05-03 18:42:04 +0000203 can_put_proto(cp);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800204 return err;
205}
206
207/*
208 * af_can tx path
209 */
210
211/**
212 * can_send - transmit a CAN frame (optional with local loopback)
213 * @skb: pointer to socket buffer with CAN frame in data section
214 * @loop: loopback for listeners on local CAN sockets (recommended default!)
215 *
Oliver Hartkopp481a8192009-09-15 01:31:34 -0700216 * Due to the loopback this routine must not be called from hardirq context.
217 *
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800218 * Return:
219 * 0 on success
220 * -ENETDOWN when the selected interface is down
221 * -ENOBUFS on full driver queue (see net_xmit_errno())
222 * -ENOMEM when local loopback failed at calling skb_clone()
223 * -EPERM when trying to send on a non-CAN interface
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200224 * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700225 * -EINVAL when the skb->data does not contain a valid CAN frame
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800226 */
227int can_send(struct sk_buff *skb, int loop)
228{
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700229 struct sk_buff *newskb = NULL;
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200230 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
231 int err = -EINVAL;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800232
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200233 if (skb->len == CAN_MTU) {
234 skb->protocol = htons(ETH_P_CAN);
235 if (unlikely(cfd->len > CAN_MAX_DLEN))
236 goto inval_skb;
237 } else if (skb->len == CANFD_MTU) {
238 skb->protocol = htons(ETH_P_CANFD);
239 if (unlikely(cfd->len > CANFD_MAX_DLEN))
240 goto inval_skb;
241 } else
242 goto inval_skb;
243
244 /*
245 * Make sure the CAN frame can pass the selected CAN netdevice.
246 * As structs can_frame and canfd_frame are similar, we can provide
247 * CAN FD frames to legacy CAN drivers as long as the length is <= 8
248 */
249 if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
250 err = -EMSGSIZE;
251 goto inval_skb;
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700252 }
253
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200254 if (unlikely(skb->dev->type != ARPHRD_CAN)) {
255 err = -EPERM;
256 goto inval_skb;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800257 }
258
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200259 if (unlikely(!(skb->dev->flags & IFF_UP))) {
260 err = -ENETDOWN;
261 goto inval_skb;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800262 }
263
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800264 skb_reset_network_header(skb);
265 skb_reset_transport_header(skb);
266
267 if (loop) {
268 /* local loopback of sent CAN frames */
269
270 /* indication for the CAN driver: do loopback */
271 skb->pkt_type = PACKET_LOOPBACK;
272
273 /*
274 * The reference to the originating sock may be required
275 * by the receiving socket to check whether the frame is
276 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
277 * Therefore we have to ensure that skb->sk remains the
278 * reference to the originating sock by restoring skb->sk
279 * after each skb_clone() or skb_orphan() usage.
280 */
281
282 if (!(skb->dev->flags & IFF_ECHO)) {
283 /*
284 * If the interface is not capable to do loopback
285 * itself, we do it here.
286 */
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700287 newskb = skb_clone(skb, GFP_ATOMIC);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800288 if (!newskb) {
289 kfree_skb(skb);
290 return -ENOMEM;
291 }
292
293 newskb->sk = skb->sk;
294 newskb->ip_summed = CHECKSUM_UNNECESSARY;
295 newskb->pkt_type = PACKET_BROADCAST;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800296 }
297 } else {
298 /* indication for the CAN driver: no loopback required */
299 skb->pkt_type = PACKET_HOST;
300 }
301
302 /* send to netdevice */
303 err = dev_queue_xmit(skb);
304 if (err > 0)
305 err = net_xmit_errno(err);
306
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700307 if (err) {
Wei Yongjunce030ed2009-02-25 00:35:44 +0000308 kfree_skb(newskb);
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700309 return err;
310 }
311
312 if (newskb)
Oliver Hartkopp481a8192009-09-15 01:31:34 -0700313 netif_rx_ni(newskb);
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700314
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800315 /* update statistics */
316 can_stats.tx_frames++;
317 can_stats.tx_frames_delta++;
318
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700319 return 0;
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200320
321inval_skb:
322 kfree_skb(skb);
323 return err;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800324}
325EXPORT_SYMBOL(can_send);
326
327/*
328 * af_can rx path
329 */
330
331static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
332{
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000333 if (!dev)
334 return &can_rx_alldev_list;
335 else
336 return (struct dev_rcv_lists *)dev->ml_priv;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800337}
338
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800339/**
340 * find_rcv_list - determine optimal filterlist inside device filter struct
341 * @can_id: pointer to CAN identifier of a given can_filter
342 * @mask: pointer to CAN mask of a given can_filter
343 * @d: pointer to the device filter struct
344 *
345 * Description:
346 * Returns the optimal filterlist to reduce the filter handling in the
347 * receive path. This function is called by service functions that need
348 * to register or unregister a can_filter in the filter lists.
349 *
350 * A filter matches in general, when
351 *
352 * <received_can_id> & mask == can_id & mask
353 *
354 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
355 * relevant bits for the filter.
356 *
357 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200358 * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
359 * frames there is a special filterlist and a special rx path filter handling.
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800360 *
361 * Return:
362 * Pointer to optimal filterlist for the given can_id/mask pair.
363 * Constistency checked mask.
364 * Reduced can_id to have a preprocessed filter compare value.
365 */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800366static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
367 struct dev_rcv_lists *d)
368{
369 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
370
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200371 /* filter for error message frames in extra filterlist */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800372 if (*mask & CAN_ERR_FLAG) {
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800373 /* clear CAN_ERR_FLAG in filter entry */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800374 *mask &= CAN_ERR_MASK;
375 return &d->rx[RX_ERR];
376 }
377
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800378 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
379
380#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
381
382 /* ensure valid values in can_mask for 'SFF only' frame filtering */
383 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
384 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800385
386 /* reduce condition testing at receive time */
387 *can_id &= *mask;
388
389 /* inverse can_id/can_mask filter */
390 if (inv)
391 return &d->rx[RX_INV];
392
393 /* mask == 0 => no condition testing at receive time */
394 if (!(*mask))
395 return &d->rx[RX_ALL];
396
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800397 /* extra filterlists for the subscription of a single non-RTR can_id */
Joe Perchesf64f9e72009-11-29 16:55:45 -0800398 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
399 !(*can_id & CAN_RTR_FLAG)) {
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800400
401 if (*can_id & CAN_EFF_FLAG) {
402 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
403 /* RFC: a future use-case for hash-tables? */
404 return &d->rx[RX_EFF];
405 }
406 } else {
407 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
408 return &d->rx_sff[*can_id];
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800409 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800410 }
411
412 /* default: filter via can_id/can_mask */
413 return &d->rx[RX_FIL];
414}
415
416/**
417 * can_rx_register - subscribe CAN frames from a specific interface
418 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
419 * @can_id: CAN identifier (see description)
420 * @mask: CAN mask (see description)
421 * @func: callback function on filter match
422 * @data: returned parameter for callback function
423 * @ident: string for calling module indentification
424 *
425 * Description:
426 * Invokes the callback function with the received sk_buff and the given
427 * parameter 'data' on a matching receive filter. A filter matches, when
428 *
429 * <received_can_id> & mask == can_id & mask
430 *
431 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200432 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800433 *
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800434 * The provided pointer to the sk_buff is guaranteed to be valid as long as
435 * the callback function is running. The callback function must *not* free
436 * the given sk_buff while processing it's task. When the given sk_buff is
437 * needed after the end of the callback function it must be cloned inside
438 * the callback function with skb_clone().
439 *
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800440 * Return:
441 * 0 on success
442 * -ENOMEM on missing cache mem to create subscription entry
443 * -ENODEV unknown device
444 */
445int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
446 void (*func)(struct sk_buff *, void *), void *data,
447 char *ident)
448{
449 struct receiver *r;
450 struct hlist_head *rl;
451 struct dev_rcv_lists *d;
452 int err = 0;
453
454 /* insert new receiver (dev,canid,mask) -> (func,data) */
455
Oliver Hartkopp8b640562010-02-02 07:21:34 -0800456 if (dev && dev->type != ARPHRD_CAN)
457 return -ENODEV;
458
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800459 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
460 if (!r)
461 return -ENOMEM;
462
463 spin_lock(&can_rcvlists_lock);
464
465 d = find_dev_rcv_lists(dev);
466 if (d) {
467 rl = find_rcv_list(&can_id, &mask, d);
468
469 r->can_id = can_id;
470 r->mask = mask;
471 r->matches = 0;
472 r->func = func;
473 r->data = data;
474 r->ident = ident;
475
476 hlist_add_head_rcu(&r->list, rl);
477 d->entries++;
478
479 can_pstats.rcv_entries++;
480 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
481 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
482 } else {
483 kmem_cache_free(rcv_cache, r);
484 err = -ENODEV;
485 }
486
487 spin_unlock(&can_rcvlists_lock);
488
489 return err;
490}
491EXPORT_SYMBOL(can_rx_register);
492
493/*
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800494 * can_rx_delete_receiver - rcu callback for single receiver entry removal
495 */
496static void can_rx_delete_receiver(struct rcu_head *rp)
497{
498 struct receiver *r = container_of(rp, struct receiver, rcu);
499
500 kmem_cache_free(rcv_cache, r);
501}
502
503/**
504 * can_rx_unregister - unsubscribe CAN frames from a specific interface
505 * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list)
506 * @can_id: CAN identifier
507 * @mask: CAN mask
508 * @func: callback function on filter match
509 * @data: returned parameter for callback function
510 *
511 * Description:
512 * Removes subscription entry depending on given (subscription) values.
513 */
514void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
515 void (*func)(struct sk_buff *, void *), void *data)
516{
517 struct receiver *r = NULL;
518 struct hlist_head *rl;
519 struct hlist_node *next;
520 struct dev_rcv_lists *d;
521
Oliver Hartkopp8b640562010-02-02 07:21:34 -0800522 if (dev && dev->type != ARPHRD_CAN)
523 return;
524
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800525 spin_lock(&can_rcvlists_lock);
526
527 d = find_dev_rcv_lists(dev);
528 if (!d) {
529 printk(KERN_ERR "BUG: receive list not found for "
530 "dev %s, id %03X, mask %03X\n",
531 DNAME(dev), can_id, mask);
532 goto out;
533 }
534
535 rl = find_rcv_list(&can_id, &mask, d);
536
537 /*
538 * Search the receiver list for the item to delete. This should
539 * exist, since no receiver may be unregistered that hasn't
540 * been registered before.
541 */
542
543 hlist_for_each_entry_rcu(r, next, rl, list) {
Joe Perchesf64f9e72009-11-29 16:55:45 -0800544 if (r->can_id == can_id && r->mask == mask &&
545 r->func == func && r->data == data)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800546 break;
547 }
548
549 /*
550 * Check for bugs in CAN protocol implementations:
551 * If no matching list item was found, the list cursor variable next
552 * will be NULL, while r will point to the last item of the list.
553 */
554
555 if (!next) {
556 printk(KERN_ERR "BUG: receive list entry not found for "
557 "dev %s, id %03X, mask %03X\n",
558 DNAME(dev), can_id, mask);
559 r = NULL;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800560 goto out;
561 }
562
563 hlist_del_rcu(&r->list);
564 d->entries--;
565
566 if (can_pstats.rcv_entries > 0)
567 can_pstats.rcv_entries--;
568
569 /* remove device structure requested by NETDEV_UNREGISTER */
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000570 if (d->remove_on_zero_entries && !d->entries) {
571 kfree(d);
572 dev->ml_priv = NULL;
573 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800574
575 out:
576 spin_unlock(&can_rcvlists_lock);
577
578 /* schedule the receiver item for deletion */
579 if (r)
580 call_rcu(&r->rcu, can_rx_delete_receiver);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800581}
582EXPORT_SYMBOL(can_rx_unregister);
583
584static inline void deliver(struct sk_buff *skb, struct receiver *r)
585{
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800586 r->func(skb, r->data);
587 r->matches++;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800588}
589
590static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
591{
592 struct receiver *r;
593 struct hlist_node *n;
594 int matches = 0;
595 struct can_frame *cf = (struct can_frame *)skb->data;
596 canid_t can_id = cf->can_id;
597
598 if (d->entries == 0)
599 return 0;
600
601 if (can_id & CAN_ERR_FLAG) {
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200602 /* check for error message frame entries only */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800603 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
604 if (can_id & r->mask) {
605 deliver(skb, r);
606 matches++;
607 }
608 }
609 return matches;
610 }
611
612 /* check for unfiltered entries */
613 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
614 deliver(skb, r);
615 matches++;
616 }
617
618 /* check for can_id/mask entries */
619 hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
620 if ((can_id & r->mask) == r->can_id) {
621 deliver(skb, r);
622 matches++;
623 }
624 }
625
626 /* check for inverted can_id/mask entries */
627 hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
628 if ((can_id & r->mask) != r->can_id) {
629 deliver(skb, r);
630 matches++;
631 }
632 }
633
Oliver Hartkoppf706644d2008-12-04 15:01:08 -0800634 /* check filterlists for single non-RTR can_ids */
635 if (can_id & CAN_RTR_FLAG)
636 return matches;
637
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800638 if (can_id & CAN_EFF_FLAG) {
639 hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
640 if (r->can_id == can_id) {
641 deliver(skb, r);
642 matches++;
643 }
644 }
645 } else {
646 can_id &= CAN_SFF_MASK;
647 hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
648 deliver(skb, r);
649 matches++;
650 }
651 }
652
653 return matches;
654}
655
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200656static void can_receive(struct sk_buff *skb, struct net_device *dev)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800657{
658 struct dev_rcv_lists *d;
659 int matches;
660
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800661 /* update statistics */
662 can_stats.rx_frames++;
663 can_stats.rx_frames_delta++;
664
665 rcu_read_lock();
666
667 /* deliver the packet to sockets listening on all devices */
668 matches = can_rcv_filter(&can_rx_alldev_list, skb);
669
670 /* find receive list for this device */
671 d = find_dev_rcv_lists(dev);
672 if (d)
673 matches += can_rcv_filter(d, skb);
674
675 rcu_read_unlock();
676
Oliver Hartkopp62bcaa12009-04-17 01:38:46 -0700677 /* consume the skbuff allocated by the netdevice driver */
678 consume_skb(skb);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800679
680 if (matches > 0) {
681 can_stats.matches++;
682 can_stats.matches_delta++;
683 }
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200684}
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800685
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200686static int can_rcv(struct sk_buff *skb, struct net_device *dev,
687 struct packet_type *pt, struct net_device *orig_dev)
688{
689 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
690
691 if (unlikely(!net_eq(dev_net(dev), &init_net)))
692 goto drop;
693
694 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
695 skb->len != CAN_MTU ||
696 cfd->len > CAN_MAX_DLEN,
697 "PF_CAN: dropped non conform CAN skbuf: "
698 "dev type %d, len %d, datalen %d\n",
699 dev->type, skb->len, cfd->len))
700 goto drop;
701
702 can_receive(skb, dev);
703 return NET_RX_SUCCESS;
704
705drop:
706 kfree_skb(skb);
707 return NET_RX_DROP;
708}
709
710static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
711 struct packet_type *pt, struct net_device *orig_dev)
712{
713 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
714
715 if (unlikely(!net_eq(dev_net(dev), &init_net)))
716 goto drop;
717
718 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
719 skb->len != CANFD_MTU ||
720 cfd->len > CANFD_MAX_DLEN,
721 "PF_CAN: dropped non conform CAN FD skbuf: "
722 "dev type %d, len %d, datalen %d\n",
723 dev->type, skb->len, cfd->len))
724 goto drop;
725
726 can_receive(skb, dev);
Oliver Hartkopp6ca8b992009-08-29 06:45:09 +0000727 return NET_RX_SUCCESS;
Oliver Hartkopp1758c092009-08-13 22:54:25 +0000728
729drop:
730 kfree_skb(skb);
Oliver Hartkopp6ca8b992009-08-29 06:45:09 +0000731 return NET_RX_DROP;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800732}
733
734/*
735 * af_can protocol functions
736 */
737
738/**
739 * can_proto_register - register CAN transport protocol
740 * @cp: pointer to CAN protocol structure
741 *
742 * Return:
743 * 0 on success
744 * -EINVAL invalid (out of range) protocol number
745 * -EBUSY protocol already in use
746 * -ENOBUF if proto_register() fails
747 */
Kurt Van Dijck16506292011-05-03 18:40:57 +0000748int can_proto_register(const struct can_proto *cp)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800749{
750 int proto = cp->protocol;
751 int err = 0;
752
753 if (proto < 0 || proto >= CAN_NPROTO) {
754 printk(KERN_ERR "can: protocol number %d out of range\n",
755 proto);
756 return -EINVAL;
757 }
758
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800759 err = proto_register(cp->prot, 0);
760 if (err < 0)
761 return err;
762
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000763 mutex_lock(&proto_tab_lock);
764
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800765 if (proto_tab[proto]) {
766 printk(KERN_ERR "can: protocol %d already registered\n",
767 proto);
768 err = -EBUSY;
Oliver Hartkopp53914b62011-03-22 08:27:25 +0000769 } else
Stephen Hemmingera9b3cd72011-08-01 16:19:00 +0000770 RCU_INIT_POINTER(proto_tab[proto], cp);
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800771
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000772 mutex_unlock(&proto_tab_lock);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800773
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800774 if (err < 0)
775 proto_unregister(cp->prot);
776
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800777 return err;
778}
779EXPORT_SYMBOL(can_proto_register);
780
781/**
782 * can_proto_unregister - unregister CAN transport protocol
783 * @cp: pointer to CAN protocol structure
784 */
Kurt Van Dijck16506292011-05-03 18:40:57 +0000785void can_proto_unregister(const struct can_proto *cp)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800786{
787 int proto = cp->protocol;
788
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000789 mutex_lock(&proto_tab_lock);
790 BUG_ON(proto_tab[proto] != cp);
Stephen Hemmingera9b3cd72011-08-01 16:19:00 +0000791 RCU_INIT_POINTER(proto_tab[proto], NULL);
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000792 mutex_unlock(&proto_tab_lock);
793
794 synchronize_rcu();
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800795
796 proto_unregister(cp->prot);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800797}
798EXPORT_SYMBOL(can_proto_unregister);
799
800/*
801 * af_can notifier to create/remove CAN netdevice specific structs
802 */
803static int can_notifier(struct notifier_block *nb, unsigned long msg,
804 void *data)
805{
806 struct net_device *dev = (struct net_device *)data;
807 struct dev_rcv_lists *d;
808
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700809 if (!net_eq(dev_net(dev), &init_net))
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800810 return NOTIFY_DONE;
811
812 if (dev->type != ARPHRD_CAN)
813 return NOTIFY_DONE;
814
815 switch (msg) {
816
817 case NETDEV_REGISTER:
818
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000819 /* create new dev_rcv_lists for this device */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800820 d = kzalloc(sizeof(*d), GFP_KERNEL);
821 if (!d) {
822 printk(KERN_ERR
823 "can: allocation of receive list failed\n");
824 return NOTIFY_DONE;
825 }
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000826 BUG_ON(dev->ml_priv);
827 dev->ml_priv = d;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800828
829 break;
830
831 case NETDEV_UNREGISTER:
832 spin_lock(&can_rcvlists_lock);
833
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000834 d = dev->ml_priv;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800835 if (d) {
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000836 if (d->entries)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800837 d->remove_on_zero_entries = 1;
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000838 else {
839 kfree(d);
840 dev->ml_priv = NULL;
841 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800842 } else
843 printk(KERN_ERR "can: notifier: receive list not "
844 "found for dev %s\n", dev->name);
845
846 spin_unlock(&can_rcvlists_lock);
847
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800848 break;
849 }
850
851 return NOTIFY_DONE;
852}
853
854/*
855 * af_can module init/exit functions
856 */
857
858static struct packet_type can_packet __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -0800859 .type = cpu_to_be16(ETH_P_CAN),
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800860 .func = can_rcv,
861};
862
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200863static struct packet_type canfd_packet __read_mostly = {
864 .type = cpu_to_be16(ETH_P_CANFD),
865 .func = canfd_rcv,
866};
867
Stephen Hemmingerec1b4cf2009-10-05 05:58:39 +0000868static const struct net_proto_family can_family_ops = {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800869 .family = PF_CAN,
870 .create = can_create,
871 .owner = THIS_MODULE,
872};
873
874/* notifier block for netdevice event */
875static struct notifier_block can_netdev_notifier __read_mostly = {
876 .notifier_call = can_notifier,
877};
878
879static __init int can_init(void)
880{
Oliver Hartkopp7c941632012-06-13 20:04:33 +0200881 /* check for correct padding to be able to use the structs similarly */
882 BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
883 offsetof(struct canfd_frame, len) ||
884 offsetof(struct can_frame, data) !=
885 offsetof(struct canfd_frame, data));
886
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800887 printk(banner);
888
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000889 memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
890
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800891 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
892 0, 0, NULL);
893 if (!rcv_cache)
894 return -ENOMEM;
895
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800896 if (stats_timer) {
897 /* the statistics are updated every second (timer triggered) */
898 setup_timer(&can_stattimer, can_stat_update, 0);
899 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
900 } else
901 can_stattimer.function = NULL;
902
903 can_init_proc();
904
905 /* protocol register */
906 sock_register(&can_family_ops);
907 register_netdevice_notifier(&can_netdev_notifier);
908 dev_add_pack(&can_packet);
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200909 dev_add_pack(&canfd_packet);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800910
911 return 0;
912}
913
914static __exit void can_exit(void)
915{
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000916 struct net_device *dev;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800917
918 if (stats_timer)
rajan.aggarwal85@gmail.comd9e64f82011-08-30 23:57:38 +0000919 del_timer_sync(&can_stattimer);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800920
921 can_remove_proc();
922
923 /* protocol unregister */
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200924 dev_remove_pack(&canfd_packet);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800925 dev_remove_pack(&can_packet);
926 unregister_netdevice_notifier(&can_netdev_notifier);
927 sock_unregister(PF_CAN);
928
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000929 /* remove created dev_rcv_lists from still registered CAN devices */
930 rcu_read_lock();
931 for_each_netdev_rcu(&init_net, dev) {
932 if (dev->type == ARPHRD_CAN && dev->ml_priv){
933
934 struct dev_rcv_lists *d = dev->ml_priv;
935
936 BUG_ON(d->entries);
937 kfree(d);
938 dev->ml_priv = NULL;
939 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800940 }
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000941 rcu_read_unlock();
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800942
Jesper Dangaard Brouer382bfee2009-06-08 03:11:38 +0000943 rcu_barrier(); /* Wait for completion of call_rcu()'s */
944
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800945 kmem_cache_destroy(rcv_cache);
946}
947
948module_init(can_init);
949module_exit(can_exit);