blob: 547bafc79e28585c44f5d59b46c9884ec1d414da [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 *
41 * Send feedback to <socketcan-users@lists.berlios.de>
42 *
43 */
44
45#include <linux/module.h>
46#include <linux/init.h>
47#include <linux/kmod.h>
48#include <linux/slab.h>
49#include <linux/list.h>
50#include <linux/spinlock.h>
51#include <linux/rcupdate.h>
52#include <linux/uaccess.h>
53#include <linux/net.h>
54#include <linux/netdevice.h>
55#include <linux/socket.h>
56#include <linux/if_ether.h>
57#include <linux/if_arp.h>
58#include <linux/skbuff.h>
59#include <linux/can.h>
60#include <linux/can/core.h>
61#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
80HLIST_HEAD(can_rx_dev_list);
81static struct dev_rcv_lists can_rx_alldev_list;
82static DEFINE_SPINLOCK(can_rcvlists_lock);
83
84static struct kmem_cache *rcv_cache __read_mostly;
85
86/* table of registered CAN protocols */
87static struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
88static DEFINE_SPINLOCK(proto_tab_lock);
89
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
98static int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
99{
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}
111
112static void can_sock_destruct(struct sock *sk)
113{
114 skb_queue_purge(&sk->sk_receive_queue);
115}
116
117static int can_create(struct net *net, struct socket *sock, int protocol)
118{
119 struct sock *sk;
120 struct can_proto *cp;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800121 int err = 0;
122
123 sock->state = SS_UNCONNECTED;
124
125 if (protocol < 0 || protocol >= CAN_NPROTO)
126 return -EINVAL;
127
128 if (net != &init_net)
129 return -EAFNOSUPPORT;
130
Johannes Berg95a5afc2008-10-16 15:24:51 -0700131#ifdef CONFIG_MODULES
132 /* try to load protocol module kernel is modular */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800133 if (!proto_tab[protocol]) {
Urs Thuermann5423dd62008-02-07 18:04:21 -0800134 err = request_module("can-proto-%d", protocol);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800135
136 /*
137 * In case of error we only print a message but don't
138 * return the error code immediately. Below we will
139 * return -EPROTONOSUPPORT
140 */
Urs Thuermann5423dd62008-02-07 18:04:21 -0800141 if (err && printk_ratelimit())
142 printk(KERN_ERR "can: request_module "
143 "(can-proto-%d) failed.\n", protocol);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800144 }
Urs Thuermann5423dd62008-02-07 18:04:21 -0800145#endif
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800146
147 spin_lock(&proto_tab_lock);
148 cp = proto_tab[protocol];
149 if (cp && !try_module_get(cp->prot->owner))
150 cp = NULL;
151 spin_unlock(&proto_tab_lock);
152
153 /* check for available protocol and correct usage */
154
155 if (!cp)
156 return -EPROTONOSUPPORT;
157
158 if (cp->type != sock->type) {
159 err = -EPROTONOSUPPORT;
160 goto errout;
161 }
162
163 if (cp->capability >= 0 && !capable(cp->capability)) {
164 err = -EPERM;
165 goto errout;
166 }
167
168 sock->ops = cp->ops;
169
170 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot);
171 if (!sk) {
172 err = -ENOMEM;
173 goto errout;
174 }
175
176 sock_init_data(sock, sk);
177 sk->sk_destruct = can_sock_destruct;
178
179 if (sk->sk_prot->init)
180 err = sk->sk_prot->init(sk);
181
182 if (err) {
183 /* release sk on errors */
184 sock_orphan(sk);
185 sock_put(sk);
186 }
187
188 errout:
189 module_put(cp->prot->owner);
190 return err;
191}
192
193/*
194 * af_can tx path
195 */
196
197/**
198 * can_send - transmit a CAN frame (optional with local loopback)
199 * @skb: pointer to socket buffer with CAN frame in data section
200 * @loop: loopback for listeners on local CAN sockets (recommended default!)
201 *
202 * Return:
203 * 0 on success
204 * -ENETDOWN when the selected interface is down
205 * -ENOBUFS on full driver queue (see net_xmit_errno())
206 * -ENOMEM when local loopback failed at calling skb_clone()
207 * -EPERM when trying to send on a non-CAN interface
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700208 * -EINVAL when the skb->data does not contain a valid CAN frame
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800209 */
210int can_send(struct sk_buff *skb, int loop)
211{
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700212 struct sk_buff *newskb = NULL;
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700213 struct can_frame *cf = (struct can_frame *)skb->data;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800214 int err;
215
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700216 if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
217 kfree_skb(skb);
218 return -EINVAL;
219 }
220
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800221 if (skb->dev->type != ARPHRD_CAN) {
222 kfree_skb(skb);
223 return -EPERM;
224 }
225
226 if (!(skb->dev->flags & IFF_UP)) {
227 kfree_skb(skb);
228 return -ENETDOWN;
229 }
230
231 skb->protocol = htons(ETH_P_CAN);
232 skb_reset_network_header(skb);
233 skb_reset_transport_header(skb);
234
235 if (loop) {
236 /* local loopback of sent CAN frames */
237
238 /* indication for the CAN driver: do loopback */
239 skb->pkt_type = PACKET_LOOPBACK;
240
241 /*
242 * The reference to the originating sock may be required
243 * by the receiving socket to check whether the frame is
244 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
245 * Therefore we have to ensure that skb->sk remains the
246 * reference to the originating sock by restoring skb->sk
247 * after each skb_clone() or skb_orphan() usage.
248 */
249
250 if (!(skb->dev->flags & IFF_ECHO)) {
251 /*
252 * If the interface is not capable to do loopback
253 * itself, we do it here.
254 */
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700255 newskb = skb_clone(skb, GFP_ATOMIC);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800256 if (!newskb) {
257 kfree_skb(skb);
258 return -ENOMEM;
259 }
260
261 newskb->sk = skb->sk;
262 newskb->ip_summed = CHECKSUM_UNNECESSARY;
263 newskb->pkt_type = PACKET_BROADCAST;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800264 }
265 } else {
266 /* indication for the CAN driver: no loopback required */
267 skb->pkt_type = PACKET_HOST;
268 }
269
270 /* send to netdevice */
271 err = dev_queue_xmit(skb);
272 if (err > 0)
273 err = net_xmit_errno(err);
274
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700275 if (err) {
Wei Yongjunce030ed2009-02-25 00:35:44 +0000276 kfree_skb(newskb);
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700277 return err;
278 }
279
280 if (newskb)
281 netif_rx(newskb);
282
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800283 /* update statistics */
284 can_stats.tx_frames++;
285 can_stats.tx_frames_delta++;
286
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700287 return 0;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800288}
289EXPORT_SYMBOL(can_send);
290
291/*
292 * af_can rx path
293 */
294
295static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
296{
297 struct dev_rcv_lists *d = NULL;
298 struct hlist_node *n;
299
300 /*
301 * find receive list for this device
302 *
303 * The hlist_for_each_entry*() macros curse through the list
304 * using the pointer variable n and set d to the containing
305 * struct in each list iteration. Therefore, after list
306 * iteration, d is unmodified when the list is empty, and it
307 * points to last list element, when the list is non-empty
308 * but no match in the loop body is found. I.e. d is *not*
309 * NULL when no match is found. We can, however, use the
310 * cursor variable n to decide if a match was found.
311 */
312
313 hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
314 if (d->dev == dev)
315 break;
316 }
317
318 return n ? d : NULL;
319}
320
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800321/**
322 * find_rcv_list - determine optimal filterlist inside device filter struct
323 * @can_id: pointer to CAN identifier of a given can_filter
324 * @mask: pointer to CAN mask of a given can_filter
325 * @d: pointer to the device filter struct
326 *
327 * Description:
328 * Returns the optimal filterlist to reduce the filter handling in the
329 * receive path. This function is called by service functions that need
330 * to register or unregister a can_filter in the filter lists.
331 *
332 * A filter matches in general, when
333 *
334 * <received_can_id> & mask == can_id & mask
335 *
336 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
337 * relevant bits for the filter.
338 *
339 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
340 * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
341 * there is a special filterlist and a special rx path filter handling.
342 *
343 * Return:
344 * Pointer to optimal filterlist for the given can_id/mask pair.
345 * Constistency checked mask.
346 * Reduced can_id to have a preprocessed filter compare value.
347 */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800348static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
349 struct dev_rcv_lists *d)
350{
351 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
352
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800353 /* filter for error frames in extra filterlist */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800354 if (*mask & CAN_ERR_FLAG) {
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800355 /* clear CAN_ERR_FLAG in filter entry */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800356 *mask &= CAN_ERR_MASK;
357 return &d->rx[RX_ERR];
358 }
359
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800360 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
361
362#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
363
364 /* ensure valid values in can_mask for 'SFF only' frame filtering */
365 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
366 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800367
368 /* reduce condition testing at receive time */
369 *can_id &= *mask;
370
371 /* inverse can_id/can_mask filter */
372 if (inv)
373 return &d->rx[RX_INV];
374
375 /* mask == 0 => no condition testing at receive time */
376 if (!(*mask))
377 return &d->rx[RX_ALL];
378
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800379 /* extra filterlists for the subscription of a single non-RTR can_id */
380 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS)
381 && !(*can_id & CAN_RTR_FLAG)) {
382
383 if (*can_id & CAN_EFF_FLAG) {
384 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
385 /* RFC: a future use-case for hash-tables? */
386 return &d->rx[RX_EFF];
387 }
388 } else {
389 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
390 return &d->rx_sff[*can_id];
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800391 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800392 }
393
394 /* default: filter via can_id/can_mask */
395 return &d->rx[RX_FIL];
396}
397
398/**
399 * can_rx_register - subscribe CAN frames from a specific interface
400 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
401 * @can_id: CAN identifier (see description)
402 * @mask: CAN mask (see description)
403 * @func: callback function on filter match
404 * @data: returned parameter for callback function
405 * @ident: string for calling module indentification
406 *
407 * Description:
408 * Invokes the callback function with the received sk_buff and the given
409 * parameter 'data' on a matching receive filter. A filter matches, when
410 *
411 * <received_can_id> & mask == can_id & mask
412 *
413 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
414 * filter for error frames (CAN_ERR_FLAG bit set in mask).
415 *
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800416 * The provided pointer to the sk_buff is guaranteed to be valid as long as
417 * the callback function is running. The callback function must *not* free
418 * the given sk_buff while processing it's task. When the given sk_buff is
419 * needed after the end of the callback function it must be cloned inside
420 * the callback function with skb_clone().
421 *
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800422 * Return:
423 * 0 on success
424 * -ENOMEM on missing cache mem to create subscription entry
425 * -ENODEV unknown device
426 */
427int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
428 void (*func)(struct sk_buff *, void *), void *data,
429 char *ident)
430{
431 struct receiver *r;
432 struct hlist_head *rl;
433 struct dev_rcv_lists *d;
434 int err = 0;
435
436 /* insert new receiver (dev,canid,mask) -> (func,data) */
437
438 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
439 if (!r)
440 return -ENOMEM;
441
442 spin_lock(&can_rcvlists_lock);
443
444 d = find_dev_rcv_lists(dev);
445 if (d) {
446 rl = find_rcv_list(&can_id, &mask, d);
447
448 r->can_id = can_id;
449 r->mask = mask;
450 r->matches = 0;
451 r->func = func;
452 r->data = data;
453 r->ident = ident;
454
455 hlist_add_head_rcu(&r->list, rl);
456 d->entries++;
457
458 can_pstats.rcv_entries++;
459 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
460 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
461 } else {
462 kmem_cache_free(rcv_cache, r);
463 err = -ENODEV;
464 }
465
466 spin_unlock(&can_rcvlists_lock);
467
468 return err;
469}
470EXPORT_SYMBOL(can_rx_register);
471
472/*
473 * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal
474 */
475static void can_rx_delete_device(struct rcu_head *rp)
476{
477 struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
478
479 kfree(d);
480}
481
482/*
483 * can_rx_delete_receiver - rcu callback for single receiver entry removal
484 */
485static void can_rx_delete_receiver(struct rcu_head *rp)
486{
487 struct receiver *r = container_of(rp, struct receiver, rcu);
488
489 kmem_cache_free(rcv_cache, r);
490}
491
492/**
493 * can_rx_unregister - unsubscribe CAN frames from a specific interface
494 * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list)
495 * @can_id: CAN identifier
496 * @mask: CAN mask
497 * @func: callback function on filter match
498 * @data: returned parameter for callback function
499 *
500 * Description:
501 * Removes subscription entry depending on given (subscription) values.
502 */
503void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
504 void (*func)(struct sk_buff *, void *), void *data)
505{
506 struct receiver *r = NULL;
507 struct hlist_head *rl;
508 struct hlist_node *next;
509 struct dev_rcv_lists *d;
510
511 spin_lock(&can_rcvlists_lock);
512
513 d = find_dev_rcv_lists(dev);
514 if (!d) {
515 printk(KERN_ERR "BUG: receive list not found for "
516 "dev %s, id %03X, mask %03X\n",
517 DNAME(dev), can_id, mask);
518 goto out;
519 }
520
521 rl = find_rcv_list(&can_id, &mask, d);
522
523 /*
524 * Search the receiver list for the item to delete. This should
525 * exist, since no receiver may be unregistered that hasn't
526 * been registered before.
527 */
528
529 hlist_for_each_entry_rcu(r, next, rl, list) {
530 if (r->can_id == can_id && r->mask == mask
531 && r->func == func && r->data == data)
532 break;
533 }
534
535 /*
536 * Check for bugs in CAN protocol implementations:
537 * If no matching list item was found, the list cursor variable next
538 * will be NULL, while r will point to the last item of the list.
539 */
540
541 if (!next) {
542 printk(KERN_ERR "BUG: receive list entry not found for "
543 "dev %s, id %03X, mask %03X\n",
544 DNAME(dev), can_id, mask);
545 r = NULL;
546 d = NULL;
547 goto out;
548 }
549
550 hlist_del_rcu(&r->list);
551 d->entries--;
552
553 if (can_pstats.rcv_entries > 0)
554 can_pstats.rcv_entries--;
555
556 /* remove device structure requested by NETDEV_UNREGISTER */
557 if (d->remove_on_zero_entries && !d->entries)
558 hlist_del_rcu(&d->list);
559 else
560 d = NULL;
561
562 out:
563 spin_unlock(&can_rcvlists_lock);
564
565 /* schedule the receiver item for deletion */
566 if (r)
567 call_rcu(&r->rcu, can_rx_delete_receiver);
568
569 /* schedule the device structure for deletion */
570 if (d)
571 call_rcu(&d->rcu, can_rx_delete_device);
572}
573EXPORT_SYMBOL(can_rx_unregister);
574
575static inline void deliver(struct sk_buff *skb, struct receiver *r)
576{
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800577 r->func(skb, r->data);
578 r->matches++;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800579}
580
581static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
582{
583 struct receiver *r;
584 struct hlist_node *n;
585 int matches = 0;
586 struct can_frame *cf = (struct can_frame *)skb->data;
587 canid_t can_id = cf->can_id;
588
589 if (d->entries == 0)
590 return 0;
591
592 if (can_id & CAN_ERR_FLAG) {
593 /* check for error frame entries only */
594 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
595 if (can_id & r->mask) {
596 deliver(skb, r);
597 matches++;
598 }
599 }
600 return matches;
601 }
602
603 /* check for unfiltered entries */
604 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
605 deliver(skb, r);
606 matches++;
607 }
608
609 /* check for can_id/mask entries */
610 hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
611 if ((can_id & r->mask) == r->can_id) {
612 deliver(skb, r);
613 matches++;
614 }
615 }
616
617 /* check for inverted can_id/mask entries */
618 hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
619 if ((can_id & r->mask) != r->can_id) {
620 deliver(skb, r);
621 matches++;
622 }
623 }
624
Oliver Hartkoppf7066442008-12-04 15:01:08 -0800625 /* check filterlists for single non-RTR can_ids */
626 if (can_id & CAN_RTR_FLAG)
627 return matches;
628
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800629 if (can_id & CAN_EFF_FLAG) {
630 hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
631 if (r->can_id == can_id) {
632 deliver(skb, r);
633 matches++;
634 }
635 }
636 } else {
637 can_id &= CAN_SFF_MASK;
638 hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
639 deliver(skb, r);
640 matches++;
641 }
642 }
643
644 return matches;
645}
646
647static int can_rcv(struct sk_buff *skb, struct net_device *dev,
648 struct packet_type *pt, struct net_device *orig_dev)
649{
650 struct dev_rcv_lists *d;
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700651 struct can_frame *cf = (struct can_frame *)skb->data;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800652 int matches;
653
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700654 if (dev->type != ARPHRD_CAN || !net_eq(dev_net(dev), &init_net)) {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800655 kfree_skb(skb);
656 return 0;
657 }
658
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700659 BUG_ON(skb->len != sizeof(struct can_frame) || cf->can_dlc > 8);
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
677 /* free the skbuff allocated by the netdevice driver */
678 kfree_skb(skb);
679
680 if (matches > 0) {
681 can_stats.matches++;
682 can_stats.matches_delta++;
683 }
684
685 return 0;
686}
687
688/*
689 * af_can protocol functions
690 */
691
692/**
693 * can_proto_register - register CAN transport protocol
694 * @cp: pointer to CAN protocol structure
695 *
696 * Return:
697 * 0 on success
698 * -EINVAL invalid (out of range) protocol number
699 * -EBUSY protocol already in use
700 * -ENOBUF if proto_register() fails
701 */
702int can_proto_register(struct can_proto *cp)
703{
704 int proto = cp->protocol;
705 int err = 0;
706
707 if (proto < 0 || proto >= CAN_NPROTO) {
708 printk(KERN_ERR "can: protocol number %d out of range\n",
709 proto);
710 return -EINVAL;
711 }
712
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800713 err = proto_register(cp->prot, 0);
714 if (err < 0)
715 return err;
716
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800717 spin_lock(&proto_tab_lock);
718 if (proto_tab[proto]) {
719 printk(KERN_ERR "can: protocol %d already registered\n",
720 proto);
721 err = -EBUSY;
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800722 } else {
723 proto_tab[proto] = cp;
724
725 /* use generic ioctl function if not defined by module */
726 if (!cp->ops->ioctl)
727 cp->ops->ioctl = can_ioctl;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800728 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800729 spin_unlock(&proto_tab_lock);
730
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800731 if (err < 0)
732 proto_unregister(cp->prot);
733
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800734 return err;
735}
736EXPORT_SYMBOL(can_proto_register);
737
738/**
739 * can_proto_unregister - unregister CAN transport protocol
740 * @cp: pointer to CAN protocol structure
741 */
742void can_proto_unregister(struct can_proto *cp)
743{
744 int proto = cp->protocol;
745
746 spin_lock(&proto_tab_lock);
747 if (!proto_tab[proto]) {
748 printk(KERN_ERR "BUG: can: protocol %d is not registered\n",
749 proto);
750 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800751 proto_tab[proto] = NULL;
752 spin_unlock(&proto_tab_lock);
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800753
754 proto_unregister(cp->prot);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800755}
756EXPORT_SYMBOL(can_proto_unregister);
757
758/*
759 * af_can notifier to create/remove CAN netdevice specific structs
760 */
761static int can_notifier(struct notifier_block *nb, unsigned long msg,
762 void *data)
763{
764 struct net_device *dev = (struct net_device *)data;
765 struct dev_rcv_lists *d;
766
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700767 if (!net_eq(dev_net(dev), &init_net))
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800768 return NOTIFY_DONE;
769
770 if (dev->type != ARPHRD_CAN)
771 return NOTIFY_DONE;
772
773 switch (msg) {
774
775 case NETDEV_REGISTER:
776
777 /*
778 * create new dev_rcv_lists for this device
779 *
780 * N.B. zeroing the struct is the correct initialization
781 * for the embedded hlist_head structs.
782 * Another list type, e.g. list_head, would require
783 * explicit initialization.
784 */
785
786 d = kzalloc(sizeof(*d), GFP_KERNEL);
787 if (!d) {
788 printk(KERN_ERR
789 "can: allocation of receive list failed\n");
790 return NOTIFY_DONE;
791 }
792 d->dev = dev;
793
794 spin_lock(&can_rcvlists_lock);
795 hlist_add_head_rcu(&d->list, &can_rx_dev_list);
796 spin_unlock(&can_rcvlists_lock);
797
798 break;
799
800 case NETDEV_UNREGISTER:
801 spin_lock(&can_rcvlists_lock);
802
803 d = find_dev_rcv_lists(dev);
804 if (d) {
805 if (d->entries) {
806 d->remove_on_zero_entries = 1;
807 d = NULL;
808 } else
809 hlist_del_rcu(&d->list);
810 } else
811 printk(KERN_ERR "can: notifier: receive list not "
812 "found for dev %s\n", dev->name);
813
814 spin_unlock(&can_rcvlists_lock);
815
816 if (d)
817 call_rcu(&d->rcu, can_rx_delete_device);
818
819 break;
820 }
821
822 return NOTIFY_DONE;
823}
824
825/*
826 * af_can module init/exit functions
827 */
828
829static struct packet_type can_packet __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -0800830 .type = cpu_to_be16(ETH_P_CAN),
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800831 .dev = NULL,
832 .func = can_rcv,
833};
834
835static struct net_proto_family can_family_ops __read_mostly = {
836 .family = PF_CAN,
837 .create = can_create,
838 .owner = THIS_MODULE,
839};
840
841/* notifier block for netdevice event */
842static struct notifier_block can_netdev_notifier __read_mostly = {
843 .notifier_call = can_notifier,
844};
845
846static __init int can_init(void)
847{
848 printk(banner);
849
850 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
851 0, 0, NULL);
852 if (!rcv_cache)
853 return -ENOMEM;
854
855 /*
856 * Insert can_rx_alldev_list for reception on all devices.
857 * This struct is zero initialized which is correct for the
858 * embedded hlist heads, the dev pointer, and the entries counter.
859 */
860
861 spin_lock(&can_rcvlists_lock);
862 hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list);
863 spin_unlock(&can_rcvlists_lock);
864
865 if (stats_timer) {
866 /* the statistics are updated every second (timer triggered) */
867 setup_timer(&can_stattimer, can_stat_update, 0);
868 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
869 } else
870 can_stattimer.function = NULL;
871
872 can_init_proc();
873
874 /* protocol register */
875 sock_register(&can_family_ops);
876 register_netdevice_notifier(&can_netdev_notifier);
877 dev_add_pack(&can_packet);
878
879 return 0;
880}
881
882static __exit void can_exit(void)
883{
884 struct dev_rcv_lists *d;
885 struct hlist_node *n, *next;
886
887 if (stats_timer)
888 del_timer(&can_stattimer);
889
890 can_remove_proc();
891
892 /* protocol unregister */
893 dev_remove_pack(&can_packet);
894 unregister_netdevice_notifier(&can_netdev_notifier);
895 sock_unregister(PF_CAN);
896
897 /* remove can_rx_dev_list */
898 spin_lock(&can_rcvlists_lock);
899 hlist_del(&can_rx_alldev_list.list);
900 hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) {
901 hlist_del(&d->list);
902 kfree(d);
903 }
904 spin_unlock(&can_rcvlists_lock);
905
906 kmem_cache_destroy(rcv_cache);
907}
908
909module_init(can_init);
910module_exit(can_exit);