blob: 702be5a2c956fd3e14ed8b7caadf3a3a9a07fbf1 [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
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 */
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
Eric Paris3f378b62009-11-05 22:18:14 -0800117static int can_create(struct net *net, struct socket *sock, int protocol,
118 int kern)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800119{
120 struct sock *sk;
121 struct can_proto *cp;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800122 int err = 0;
123
124 sock->state = SS_UNCONNECTED;
125
126 if (protocol < 0 || protocol >= CAN_NPROTO)
127 return -EINVAL;
128
Octavian Purdila09ad9bc2009-11-25 15:14:13 -0800129 if (!net_eq(net, &init_net))
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800130 return -EAFNOSUPPORT;
131
Johannes Berg95a5afc2008-10-16 15:24:51 -0700132#ifdef CONFIG_MODULES
133 /* try to load protocol module kernel is modular */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800134 if (!proto_tab[protocol]) {
Urs Thuermann5423dd62008-02-07 18:04:21 -0800135 err = request_module("can-proto-%d", protocol);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800136
137 /*
138 * In case of error we only print a message but don't
139 * return the error code immediately. Below we will
140 * return -EPROTONOSUPPORT
141 */
Urs Thuermann5423dd62008-02-07 18:04:21 -0800142 if (err && printk_ratelimit())
143 printk(KERN_ERR "can: request_module "
144 "(can-proto-%d) failed.\n", protocol);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800145 }
Urs Thuermann5423dd62008-02-07 18:04:21 -0800146#endif
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800147
148 spin_lock(&proto_tab_lock);
149 cp = proto_tab[protocol];
150 if (cp && !try_module_get(cp->prot->owner))
151 cp = NULL;
152 spin_unlock(&proto_tab_lock);
153
154 /* check for available protocol and correct usage */
155
156 if (!cp)
157 return -EPROTONOSUPPORT;
158
159 if (cp->type != sock->type) {
160 err = -EPROTONOSUPPORT;
161 goto errout;
162 }
163
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800164 sock->ops = cp->ops;
165
166 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot);
167 if (!sk) {
168 err = -ENOMEM;
169 goto errout;
170 }
171
172 sock_init_data(sock, sk);
173 sk->sk_destruct = can_sock_destruct;
174
175 if (sk->sk_prot->init)
176 err = sk->sk_prot->init(sk);
177
178 if (err) {
179 /* release sk on errors */
180 sock_orphan(sk);
181 sock_put(sk);
182 }
183
184 errout:
185 module_put(cp->prot->owner);
186 return err;
187}
188
189/*
190 * af_can tx path
191 */
192
193/**
194 * can_send - transmit a CAN frame (optional with local loopback)
195 * @skb: pointer to socket buffer with CAN frame in data section
196 * @loop: loopback for listeners on local CAN sockets (recommended default!)
197 *
Oliver Hartkopp481a8192009-09-15 01:31:34 -0700198 * Due to the loopback this routine must not be called from hardirq context.
199 *
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800200 * Return:
201 * 0 on success
202 * -ENETDOWN when the selected interface is down
203 * -ENOBUFS on full driver queue (see net_xmit_errno())
204 * -ENOMEM when local loopback failed at calling skb_clone()
205 * -EPERM when trying to send on a non-CAN interface
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700206 * -EINVAL when the skb->data does not contain a valid CAN frame
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800207 */
208int can_send(struct sk_buff *skb, int loop)
209{
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700210 struct sk_buff *newskb = NULL;
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700211 struct can_frame *cf = (struct can_frame *)skb->data;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800212 int err;
213
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700214 if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
215 kfree_skb(skb);
216 return -EINVAL;
217 }
218
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800219 if (skb->dev->type != ARPHRD_CAN) {
220 kfree_skb(skb);
221 return -EPERM;
222 }
223
224 if (!(skb->dev->flags & IFF_UP)) {
225 kfree_skb(skb);
226 return -ENETDOWN;
227 }
228
229 skb->protocol = htons(ETH_P_CAN);
230 skb_reset_network_header(skb);
231 skb_reset_transport_header(skb);
232
233 if (loop) {
234 /* local loopback of sent CAN frames */
235
236 /* indication for the CAN driver: do loopback */
237 skb->pkt_type = PACKET_LOOPBACK;
238
239 /*
240 * The reference to the originating sock may be required
241 * by the receiving socket to check whether the frame is
242 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
243 * Therefore we have to ensure that skb->sk remains the
244 * reference to the originating sock by restoring skb->sk
245 * after each skb_clone() or skb_orphan() usage.
246 */
247
248 if (!(skb->dev->flags & IFF_ECHO)) {
249 /*
250 * If the interface is not capable to do loopback
251 * itself, we do it here.
252 */
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700253 newskb = skb_clone(skb, GFP_ATOMIC);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800254 if (!newskb) {
255 kfree_skb(skb);
256 return -ENOMEM;
257 }
258
259 newskb->sk = skb->sk;
260 newskb->ip_summed = CHECKSUM_UNNECESSARY;
261 newskb->pkt_type = PACKET_BROADCAST;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800262 }
263 } else {
264 /* indication for the CAN driver: no loopback required */
265 skb->pkt_type = PACKET_HOST;
266 }
267
268 /* send to netdevice */
269 err = dev_queue_xmit(skb);
270 if (err > 0)
271 err = net_xmit_errno(err);
272
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700273 if (err) {
Wei Yongjunce030ed2009-02-25 00:35:44 +0000274 kfree_skb(newskb);
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700275 return err;
276 }
277
278 if (newskb)
Oliver Hartkopp481a8192009-09-15 01:31:34 -0700279 netif_rx_ni(newskb);
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700280
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800281 /* update statistics */
282 can_stats.tx_frames++;
283 can_stats.tx_frames_delta++;
284
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700285 return 0;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800286}
287EXPORT_SYMBOL(can_send);
288
289/*
290 * af_can rx path
291 */
292
293static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
294{
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000295 if (!dev)
296 return &can_rx_alldev_list;
297 else
298 return (struct dev_rcv_lists *)dev->ml_priv;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800299}
300
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800301/**
302 * find_rcv_list - determine optimal filterlist inside device filter struct
303 * @can_id: pointer to CAN identifier of a given can_filter
304 * @mask: pointer to CAN mask of a given can_filter
305 * @d: pointer to the device filter struct
306 *
307 * Description:
308 * Returns the optimal filterlist to reduce the filter handling in the
309 * receive path. This function is called by service functions that need
310 * to register or unregister a can_filter in the filter lists.
311 *
312 * A filter matches in general, when
313 *
314 * <received_can_id> & mask == can_id & mask
315 *
316 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
317 * relevant bits for the filter.
318 *
319 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
320 * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
321 * there is a special filterlist and a special rx path filter handling.
322 *
323 * Return:
324 * Pointer to optimal filterlist for the given can_id/mask pair.
325 * Constistency checked mask.
326 * Reduced can_id to have a preprocessed filter compare value.
327 */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800328static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
329 struct dev_rcv_lists *d)
330{
331 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
332
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800333 /* filter for error frames in extra filterlist */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800334 if (*mask & CAN_ERR_FLAG) {
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800335 /* clear CAN_ERR_FLAG in filter entry */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800336 *mask &= CAN_ERR_MASK;
337 return &d->rx[RX_ERR];
338 }
339
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800340 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
341
342#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
343
344 /* ensure valid values in can_mask for 'SFF only' frame filtering */
345 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
346 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800347
348 /* reduce condition testing at receive time */
349 *can_id &= *mask;
350
351 /* inverse can_id/can_mask filter */
352 if (inv)
353 return &d->rx[RX_INV];
354
355 /* mask == 0 => no condition testing at receive time */
356 if (!(*mask))
357 return &d->rx[RX_ALL];
358
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800359 /* extra filterlists for the subscription of a single non-RTR can_id */
Joe Perchesf64f9e72009-11-29 16:55:45 -0800360 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
361 !(*can_id & CAN_RTR_FLAG)) {
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800362
363 if (*can_id & CAN_EFF_FLAG) {
364 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) {
365 /* RFC: a future use-case for hash-tables? */
366 return &d->rx[RX_EFF];
367 }
368 } else {
369 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
370 return &d->rx_sff[*can_id];
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800371 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800372 }
373
374 /* default: filter via can_id/can_mask */
375 return &d->rx[RX_FIL];
376}
377
378/**
379 * can_rx_register - subscribe CAN frames from a specific interface
380 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
381 * @can_id: CAN identifier (see description)
382 * @mask: CAN mask (see description)
383 * @func: callback function on filter match
384 * @data: returned parameter for callback function
385 * @ident: string for calling module indentification
386 *
387 * Description:
388 * Invokes the callback function with the received sk_buff and the given
389 * parameter 'data' on a matching receive filter. A filter matches, when
390 *
391 * <received_can_id> & mask == can_id & mask
392 *
393 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
394 * filter for error frames (CAN_ERR_FLAG bit set in mask).
395 *
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800396 * The provided pointer to the sk_buff is guaranteed to be valid as long as
397 * the callback function is running. The callback function must *not* free
398 * the given sk_buff while processing it's task. When the given sk_buff is
399 * needed after the end of the callback function it must be cloned inside
400 * the callback function with skb_clone().
401 *
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800402 * Return:
403 * 0 on success
404 * -ENOMEM on missing cache mem to create subscription entry
405 * -ENODEV unknown device
406 */
407int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
408 void (*func)(struct sk_buff *, void *), void *data,
409 char *ident)
410{
411 struct receiver *r;
412 struct hlist_head *rl;
413 struct dev_rcv_lists *d;
414 int err = 0;
415
416 /* insert new receiver (dev,canid,mask) -> (func,data) */
417
Oliver Hartkopp8b640562010-02-02 07:21:34 -0800418 if (dev && dev->type != ARPHRD_CAN)
419 return -ENODEV;
420
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800421 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
422 if (!r)
423 return -ENOMEM;
424
425 spin_lock(&can_rcvlists_lock);
426
427 d = find_dev_rcv_lists(dev);
428 if (d) {
429 rl = find_rcv_list(&can_id, &mask, d);
430
431 r->can_id = can_id;
432 r->mask = mask;
433 r->matches = 0;
434 r->func = func;
435 r->data = data;
436 r->ident = ident;
437
438 hlist_add_head_rcu(&r->list, rl);
439 d->entries++;
440
441 can_pstats.rcv_entries++;
442 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
443 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
444 } else {
445 kmem_cache_free(rcv_cache, r);
446 err = -ENODEV;
447 }
448
449 spin_unlock(&can_rcvlists_lock);
450
451 return err;
452}
453EXPORT_SYMBOL(can_rx_register);
454
455/*
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800456 * can_rx_delete_receiver - rcu callback for single receiver entry removal
457 */
458static void can_rx_delete_receiver(struct rcu_head *rp)
459{
460 struct receiver *r = container_of(rp, struct receiver, rcu);
461
462 kmem_cache_free(rcv_cache, r);
463}
464
465/**
466 * can_rx_unregister - unsubscribe CAN frames from a specific interface
467 * @dev: pointer to netdevice (NULL => unsubcribe from 'all' CAN devices list)
468 * @can_id: CAN identifier
469 * @mask: CAN mask
470 * @func: callback function on filter match
471 * @data: returned parameter for callback function
472 *
473 * Description:
474 * Removes subscription entry depending on given (subscription) values.
475 */
476void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
477 void (*func)(struct sk_buff *, void *), void *data)
478{
479 struct receiver *r = NULL;
480 struct hlist_head *rl;
481 struct hlist_node *next;
482 struct dev_rcv_lists *d;
483
Oliver Hartkopp8b640562010-02-02 07:21:34 -0800484 if (dev && dev->type != ARPHRD_CAN)
485 return;
486
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800487 spin_lock(&can_rcvlists_lock);
488
489 d = find_dev_rcv_lists(dev);
490 if (!d) {
491 printk(KERN_ERR "BUG: receive list not found for "
492 "dev %s, id %03X, mask %03X\n",
493 DNAME(dev), can_id, mask);
494 goto out;
495 }
496
497 rl = find_rcv_list(&can_id, &mask, d);
498
499 /*
500 * Search the receiver list for the item to delete. This should
501 * exist, since no receiver may be unregistered that hasn't
502 * been registered before.
503 */
504
505 hlist_for_each_entry_rcu(r, next, rl, list) {
Joe Perchesf64f9e72009-11-29 16:55:45 -0800506 if (r->can_id == can_id && r->mask == mask &&
507 r->func == func && r->data == data)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800508 break;
509 }
510
511 /*
512 * Check for bugs in CAN protocol implementations:
513 * If no matching list item was found, the list cursor variable next
514 * will be NULL, while r will point to the last item of the list.
515 */
516
517 if (!next) {
518 printk(KERN_ERR "BUG: receive list entry not found for "
519 "dev %s, id %03X, mask %03X\n",
520 DNAME(dev), can_id, mask);
521 r = NULL;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800522 goto out;
523 }
524
525 hlist_del_rcu(&r->list);
526 d->entries--;
527
528 if (can_pstats.rcv_entries > 0)
529 can_pstats.rcv_entries--;
530
531 /* remove device structure requested by NETDEV_UNREGISTER */
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000532 if (d->remove_on_zero_entries && !d->entries) {
533 kfree(d);
534 dev->ml_priv = NULL;
535 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800536
537 out:
538 spin_unlock(&can_rcvlists_lock);
539
540 /* schedule the receiver item for deletion */
541 if (r)
542 call_rcu(&r->rcu, can_rx_delete_receiver);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800543}
544EXPORT_SYMBOL(can_rx_unregister);
545
546static inline void deliver(struct sk_buff *skb, struct receiver *r)
547{
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800548 r->func(skb, r->data);
549 r->matches++;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800550}
551
552static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
553{
554 struct receiver *r;
555 struct hlist_node *n;
556 int matches = 0;
557 struct can_frame *cf = (struct can_frame *)skb->data;
558 canid_t can_id = cf->can_id;
559
560 if (d->entries == 0)
561 return 0;
562
563 if (can_id & CAN_ERR_FLAG) {
564 /* check for error frame entries only */
565 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
566 if (can_id & r->mask) {
567 deliver(skb, r);
568 matches++;
569 }
570 }
571 return matches;
572 }
573
574 /* check for unfiltered entries */
575 hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) {
576 deliver(skb, r);
577 matches++;
578 }
579
580 /* check for can_id/mask entries */
581 hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) {
582 if ((can_id & r->mask) == r->can_id) {
583 deliver(skb, r);
584 matches++;
585 }
586 }
587
588 /* check for inverted can_id/mask entries */
589 hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) {
590 if ((can_id & r->mask) != r->can_id) {
591 deliver(skb, r);
592 matches++;
593 }
594 }
595
Oliver Hartkoppf706644d2008-12-04 15:01:08 -0800596 /* check filterlists for single non-RTR can_ids */
597 if (can_id & CAN_RTR_FLAG)
598 return matches;
599
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800600 if (can_id & CAN_EFF_FLAG) {
601 hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) {
602 if (r->can_id == can_id) {
603 deliver(skb, r);
604 matches++;
605 }
606 }
607 } else {
608 can_id &= CAN_SFF_MASK;
609 hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) {
610 deliver(skb, r);
611 matches++;
612 }
613 }
614
615 return matches;
616}
617
618static int can_rcv(struct sk_buff *skb, struct net_device *dev,
619 struct packet_type *pt, struct net_device *orig_dev)
620{
621 struct dev_rcv_lists *d;
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700622 struct can_frame *cf = (struct can_frame *)skb->data;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800623 int matches;
624
Oliver Hartkopp1758c092009-08-13 22:54:25 +0000625 if (!net_eq(dev_net(dev), &init_net))
626 goto drop;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800627
Oliver Hartkopp1758c092009-08-13 22:54:25 +0000628 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
629 skb->len != sizeof(struct can_frame) ||
630 cf->can_dlc > 8,
631 "PF_CAN: dropped non conform skbuf: "
632 "dev type %d, len %d, can_dlc %d\n",
633 dev->type, skb->len, cf->can_dlc))
634 goto drop;
Oliver Hartkopp7f2d38e2008-07-05 23:38:43 -0700635
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800636 /* update statistics */
637 can_stats.rx_frames++;
638 can_stats.rx_frames_delta++;
639
640 rcu_read_lock();
641
642 /* deliver the packet to sockets listening on all devices */
643 matches = can_rcv_filter(&can_rx_alldev_list, skb);
644
645 /* find receive list for this device */
646 d = find_dev_rcv_lists(dev);
647 if (d)
648 matches += can_rcv_filter(d, skb);
649
650 rcu_read_unlock();
651
Oliver Hartkopp62bcaa12009-04-17 01:38:46 -0700652 /* consume the skbuff allocated by the netdevice driver */
653 consume_skb(skb);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800654
655 if (matches > 0) {
656 can_stats.matches++;
657 can_stats.matches_delta++;
658 }
659
Oliver Hartkopp6ca8b992009-08-29 06:45:09 +0000660 return NET_RX_SUCCESS;
Oliver Hartkopp1758c092009-08-13 22:54:25 +0000661
662drop:
663 kfree_skb(skb);
Oliver Hartkopp6ca8b992009-08-29 06:45:09 +0000664 return NET_RX_DROP;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800665}
666
667/*
668 * af_can protocol functions
669 */
670
671/**
672 * can_proto_register - register CAN transport protocol
673 * @cp: pointer to CAN protocol structure
674 *
675 * Return:
676 * 0 on success
677 * -EINVAL invalid (out of range) protocol number
678 * -EBUSY protocol already in use
679 * -ENOBUF if proto_register() fails
680 */
681int can_proto_register(struct can_proto *cp)
682{
683 int proto = cp->protocol;
684 int err = 0;
685
686 if (proto < 0 || proto >= CAN_NPROTO) {
687 printk(KERN_ERR "can: protocol number %d out of range\n",
688 proto);
689 return -EINVAL;
690 }
691
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800692 err = proto_register(cp->prot, 0);
693 if (err < 0)
694 return err;
695
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800696 spin_lock(&proto_tab_lock);
697 if (proto_tab[proto]) {
698 printk(KERN_ERR "can: protocol %d already registered\n",
699 proto);
700 err = -EBUSY;
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800701 } else {
702 proto_tab[proto] = cp;
703
704 /* use generic ioctl function if not defined by module */
705 if (!cp->ops->ioctl)
706 cp->ops->ioctl = can_ioctl;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800707 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800708 spin_unlock(&proto_tab_lock);
709
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800710 if (err < 0)
711 proto_unregister(cp->prot);
712
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800713 return err;
714}
715EXPORT_SYMBOL(can_proto_register);
716
717/**
718 * can_proto_unregister - unregister CAN transport protocol
719 * @cp: pointer to CAN protocol structure
720 */
721void can_proto_unregister(struct can_proto *cp)
722{
723 int proto = cp->protocol;
724
725 spin_lock(&proto_tab_lock);
726 if (!proto_tab[proto]) {
727 printk(KERN_ERR "BUG: can: protocol %d is not registered\n",
728 proto);
729 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800730 proto_tab[proto] = NULL;
731 spin_unlock(&proto_tab_lock);
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800732
733 proto_unregister(cp->prot);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800734}
735EXPORT_SYMBOL(can_proto_unregister);
736
737/*
738 * af_can notifier to create/remove CAN netdevice specific structs
739 */
740static int can_notifier(struct notifier_block *nb, unsigned long msg,
741 void *data)
742{
743 struct net_device *dev = (struct net_device *)data;
744 struct dev_rcv_lists *d;
745
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700746 if (!net_eq(dev_net(dev), &init_net))
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800747 return NOTIFY_DONE;
748
749 if (dev->type != ARPHRD_CAN)
750 return NOTIFY_DONE;
751
752 switch (msg) {
753
754 case NETDEV_REGISTER:
755
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000756 /* create new dev_rcv_lists for this device */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800757 d = kzalloc(sizeof(*d), GFP_KERNEL);
758 if (!d) {
759 printk(KERN_ERR
760 "can: allocation of receive list failed\n");
761 return NOTIFY_DONE;
762 }
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000763 BUG_ON(dev->ml_priv);
764 dev->ml_priv = d;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800765
766 break;
767
768 case NETDEV_UNREGISTER:
769 spin_lock(&can_rcvlists_lock);
770
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000771 d = dev->ml_priv;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800772 if (d) {
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000773 if (d->entries)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800774 d->remove_on_zero_entries = 1;
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000775 else {
776 kfree(d);
777 dev->ml_priv = NULL;
778 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800779 } else
780 printk(KERN_ERR "can: notifier: receive list not "
781 "found for dev %s\n", dev->name);
782
783 spin_unlock(&can_rcvlists_lock);
784
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800785 break;
786 }
787
788 return NOTIFY_DONE;
789}
790
791/*
792 * af_can module init/exit functions
793 */
794
795static struct packet_type can_packet __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -0800796 .type = cpu_to_be16(ETH_P_CAN),
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800797 .dev = NULL,
798 .func = can_rcv,
799};
800
Stephen Hemmingerec1b4cf2009-10-05 05:58:39 +0000801static const struct net_proto_family can_family_ops = {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800802 .family = PF_CAN,
803 .create = can_create,
804 .owner = THIS_MODULE,
805};
806
807/* notifier block for netdevice event */
808static struct notifier_block can_netdev_notifier __read_mostly = {
809 .notifier_call = can_notifier,
810};
811
812static __init int can_init(void)
813{
814 printk(banner);
815
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000816 memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
817
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800818 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
819 0, 0, NULL);
820 if (!rcv_cache)
821 return -ENOMEM;
822
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800823 if (stats_timer) {
824 /* the statistics are updated every second (timer triggered) */
825 setup_timer(&can_stattimer, can_stat_update, 0);
826 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
827 } else
828 can_stattimer.function = NULL;
829
830 can_init_proc();
831
832 /* protocol register */
833 sock_register(&can_family_ops);
834 register_netdevice_notifier(&can_netdev_notifier);
835 dev_add_pack(&can_packet);
836
837 return 0;
838}
839
840static __exit void can_exit(void)
841{
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000842 struct net_device *dev;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800843
844 if (stats_timer)
845 del_timer(&can_stattimer);
846
847 can_remove_proc();
848
849 /* protocol unregister */
850 dev_remove_pack(&can_packet);
851 unregister_netdevice_notifier(&can_netdev_notifier);
852 sock_unregister(PF_CAN);
853
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000854 /* remove created dev_rcv_lists from still registered CAN devices */
855 rcu_read_lock();
856 for_each_netdev_rcu(&init_net, dev) {
857 if (dev->type == ARPHRD_CAN && dev->ml_priv){
858
859 struct dev_rcv_lists *d = dev->ml_priv;
860
861 BUG_ON(d->entries);
862 kfree(d);
863 dev->ml_priv = NULL;
864 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800865 }
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000866 rcu_read_unlock();
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800867
Jesper Dangaard Brouer382bfee2009-06-08 03:11:38 +0000868 rcu_barrier(); /* Wait for completion of call_rcu()'s */
869
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800870 kmem_cache_destroy(rcv_cache);
871}
872
873module_init(can_init);
874module_exit(can_exit);