blob: 166d436196c14480184859e2bcaadeb7c5514f3a [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>
Oliver Hartkopp0ae89be2014-01-30 10:11:28 +010060#include <linux/can/skb.h>
Manuel Zerpiesd751e622011-06-16 02:08:01 +000061#include <linux/ratelimit.h>
Oliver Hartkopp0d665482007-11-16 15:52:17 -080062#include <net/net_namespace.h>
63#include <net/sock.h>
64
65#include "af_can.h"
66
Oliver Hartkopp0d665482007-11-16 15:52:17 -080067MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
68MODULE_LICENSE("Dual BSD/GPL");
69MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
70 "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
71
72MODULE_ALIAS_NETPROTO(PF_CAN);
73
74static int stats_timer __read_mostly = 1;
75module_param(stats_timer, int, S_IRUGO);
76MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
77
Oliver Hartkopp20dd3852009-12-25 06:47:47 +000078/* receive filters subscribed for 'all' CAN devices */
79struct dev_rcv_lists can_rx_alldev_list;
Oliver Hartkopp0d665482007-11-16 15:52:17 -080080static DEFINE_SPINLOCK(can_rcvlists_lock);
81
82static struct kmem_cache *rcv_cache __read_mostly;
83
84/* table of registered CAN protocols */
Kurt Van Dijck16506292011-05-03 18:40:57 +000085static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +000086static DEFINE_MUTEX(proto_tab_lock);
Oliver Hartkopp0d665482007-11-16 15:52:17 -080087
88struct timer_list can_stattimer; /* timer for statistics update */
89struct s_stats can_stats; /* packet statistics */
90struct s_pstats can_pstats; /* receive list statistics */
91
Oliver Hartkoppd3b58c42015-06-26 11:58:19 +020092static atomic_t skbcounter = ATOMIC_INIT(0);
93
Oliver Hartkopp0d665482007-11-16 15:52:17 -080094/*
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
Eric W. Biederman11aa9c22015-05-08 21:09:13 -0500184 sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800185 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 Hartkopp9694390162015-02-23 20:37:54 +0100264 skb->ip_summed = CHECKSUM_UNNECESSARY;
265
266 skb_reset_mac_header(skb);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800267 skb_reset_network_header(skb);
268 skb_reset_transport_header(skb);
269
270 if (loop) {
271 /* local loopback of sent CAN frames */
272
273 /* indication for the CAN driver: do loopback */
274 skb->pkt_type = PACKET_LOOPBACK;
275
276 /*
277 * The reference to the originating sock may be required
278 * by the receiving socket to check whether the frame is
279 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
280 * Therefore we have to ensure that skb->sk remains the
281 * reference to the originating sock by restoring skb->sk
282 * after each skb_clone() or skb_orphan() usage.
283 */
284
285 if (!(skb->dev->flags & IFF_ECHO)) {
286 /*
287 * If the interface is not capable to do loopback
288 * itself, we do it here.
289 */
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700290 newskb = skb_clone(skb, GFP_ATOMIC);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800291 if (!newskb) {
292 kfree_skb(skb);
293 return -ENOMEM;
294 }
295
Oliver Hartkopp0ae89be2014-01-30 10:11:28 +0100296 can_skb_set_owner(newskb, skb->sk);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800297 newskb->ip_summed = CHECKSUM_UNNECESSARY;
298 newskb->pkt_type = PACKET_BROADCAST;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800299 }
300 } else {
301 /* indication for the CAN driver: no loopback required */
302 skb->pkt_type = PACKET_HOST;
303 }
304
305 /* send to netdevice */
306 err = dev_queue_xmit(skb);
307 if (err > 0)
308 err = net_xmit_errno(err);
309
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700310 if (err) {
Wei Yongjunce030ed2009-02-25 00:35:44 +0000311 kfree_skb(newskb);
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700312 return err;
313 }
314
Oliver Hartkoppd3b58c42015-06-26 11:58:19 +0200315 if (newskb)
Oliver Hartkopp481a8192009-09-15 01:31:34 -0700316 netif_rx_ni(newskb);
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700317
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800318 /* update statistics */
319 can_stats.tx_frames++;
320 can_stats.tx_frames_delta++;
321
Oliver Hartkoppc2ab7ac2008-05-08 02:49:55 -0700322 return 0;
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200323
324inval_skb:
325 kfree_skb(skb);
326 return err;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800327}
328EXPORT_SYMBOL(can_send);
329
330/*
331 * af_can rx path
332 */
333
334static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
335{
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000336 if (!dev)
337 return &can_rx_alldev_list;
338 else
339 return (struct dev_rcv_lists *)dev->ml_priv;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800340}
341
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800342/**
Oliver Hartkopp45c70022014-04-02 20:25:26 +0200343 * effhash - hash function for 29 bit CAN identifier reduction
344 * @can_id: 29 bit CAN identifier
345 *
346 * Description:
347 * To reduce the linear traversal in one linked list of _single_ EFF CAN
348 * frame subscriptions the 29 bit identifier is mapped to 10 bits.
349 * (see CAN_EFF_RCV_HASH_BITS definition)
350 *
351 * Return:
352 * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
353 */
354static unsigned int effhash(canid_t can_id)
355{
356 unsigned int hash;
357
358 hash = can_id;
359 hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
360 hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
361
362 return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
363}
364
365/**
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800366 * find_rcv_list - determine optimal filterlist inside device filter struct
367 * @can_id: pointer to CAN identifier of a given can_filter
368 * @mask: pointer to CAN mask of a given can_filter
369 * @d: pointer to the device filter struct
370 *
371 * Description:
372 * Returns the optimal filterlist to reduce the filter handling in the
373 * receive path. This function is called by service functions that need
374 * to register or unregister a can_filter in the filter lists.
375 *
376 * A filter matches in general, when
377 *
378 * <received_can_id> & mask == can_id & mask
379 *
380 * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
381 * relevant bits for the filter.
382 *
383 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200384 * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
385 * frames there is a special filterlist and a special rx path filter handling.
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800386 *
387 * Return:
388 * Pointer to optimal filterlist for the given can_id/mask pair.
389 * Constistency checked mask.
390 * Reduced can_id to have a preprocessed filter compare value.
391 */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800392static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
393 struct dev_rcv_lists *d)
394{
395 canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
396
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200397 /* filter for error message frames in extra filterlist */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800398 if (*mask & CAN_ERR_FLAG) {
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800399 /* clear CAN_ERR_FLAG in filter entry */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800400 *mask &= CAN_ERR_MASK;
401 return &d->rx[RX_ERR];
402 }
403
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800404 /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
405
406#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
407
408 /* ensure valid values in can_mask for 'SFF only' frame filtering */
409 if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
410 *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800411
412 /* reduce condition testing at receive time */
413 *can_id &= *mask;
414
415 /* inverse can_id/can_mask filter */
416 if (inv)
417 return &d->rx[RX_INV];
418
419 /* mask == 0 => no condition testing at receive time */
420 if (!(*mask))
421 return &d->rx[RX_ALL];
422
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800423 /* extra filterlists for the subscription of a single non-RTR can_id */
Joe Perchesf64f9e72009-11-29 16:55:45 -0800424 if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
425 !(*can_id & CAN_RTR_FLAG)) {
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800426
427 if (*can_id & CAN_EFF_FLAG) {
Oliver Hartkopp45c70022014-04-02 20:25:26 +0200428 if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
429 return &d->rx_eff[effhash(*can_id)];
Oliver Hartkoppd253eee2008-12-03 15:52:35 -0800430 } else {
431 if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
432 return &d->rx_sff[*can_id];
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800433 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800434 }
435
436 /* default: filter via can_id/can_mask */
437 return &d->rx[RX_FIL];
438}
439
440/**
441 * can_rx_register - subscribe CAN frames from a specific interface
442 * @dev: pointer to netdevice (NULL => subcribe from 'all' CAN devices list)
443 * @can_id: CAN identifier (see description)
444 * @mask: CAN mask (see description)
445 * @func: callback function on filter match
446 * @data: returned parameter for callback function
Maxime Jayat3f794102013-10-12 01:29:46 +0200447 * @ident: string for calling module identification
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800448 *
449 * Description:
450 * Invokes the callback function with the received sk_buff and the given
451 * parameter 'data' on a matching receive filter. A filter matches, when
452 *
453 * <received_can_id> & mask == can_id & mask
454 *
455 * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200456 * filter for error message frames (CAN_ERR_FLAG bit set in mask).
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800457 *
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800458 * The provided pointer to the sk_buff is guaranteed to be valid as long as
459 * the callback function is running. The callback function must *not* free
460 * the given sk_buff while processing it's task. When the given sk_buff is
461 * needed after the end of the callback function it must be cloned inside
462 * the callback function with skb_clone().
463 *
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800464 * Return:
465 * 0 on success
466 * -ENOMEM on missing cache mem to create subscription entry
467 * -ENODEV unknown device
468 */
469int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
470 void (*func)(struct sk_buff *, void *), void *data,
471 char *ident)
472{
473 struct receiver *r;
474 struct hlist_head *rl;
475 struct dev_rcv_lists *d;
476 int err = 0;
477
478 /* insert new receiver (dev,canid,mask) -> (func,data) */
479
Oliver Hartkopp8b640562010-02-02 07:21:34 -0800480 if (dev && dev->type != ARPHRD_CAN)
481 return -ENODEV;
482
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800483 r = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
484 if (!r)
485 return -ENOMEM;
486
487 spin_lock(&can_rcvlists_lock);
488
489 d = find_dev_rcv_lists(dev);
490 if (d) {
491 rl = find_rcv_list(&can_id, &mask, d);
492
493 r->can_id = can_id;
494 r->mask = mask;
495 r->matches = 0;
496 r->func = func;
497 r->data = data;
498 r->ident = ident;
499
500 hlist_add_head_rcu(&r->list, rl);
501 d->entries++;
502
503 can_pstats.rcv_entries++;
504 if (can_pstats.rcv_entries_max < can_pstats.rcv_entries)
505 can_pstats.rcv_entries_max = can_pstats.rcv_entries;
506 } else {
507 kmem_cache_free(rcv_cache, r);
508 err = -ENODEV;
509 }
510
511 spin_unlock(&can_rcvlists_lock);
512
513 return err;
514}
515EXPORT_SYMBOL(can_rx_register);
516
517/*
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800518 * can_rx_delete_receiver - rcu callback for single receiver entry removal
519 */
520static void can_rx_delete_receiver(struct rcu_head *rp)
521{
522 struct receiver *r = container_of(rp, struct receiver, rcu);
523
524 kmem_cache_free(rcv_cache, r);
525}
526
527/**
528 * can_rx_unregister - unsubscribe CAN frames from a specific interface
Jeremiah Mahler069f8452014-12-05 09:54:38 -0800529 * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800530 * @can_id: CAN identifier
531 * @mask: CAN mask
532 * @func: callback function on filter match
533 * @data: returned parameter for callback function
534 *
535 * Description:
536 * Removes subscription entry depending on given (subscription) values.
537 */
538void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
539 void (*func)(struct sk_buff *, void *), void *data)
540{
541 struct receiver *r = NULL;
542 struct hlist_head *rl;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800543 struct dev_rcv_lists *d;
544
Oliver Hartkopp8b640562010-02-02 07:21:34 -0800545 if (dev && dev->type != ARPHRD_CAN)
546 return;
547
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800548 spin_lock(&can_rcvlists_lock);
549
550 d = find_dev_rcv_lists(dev);
551 if (!d) {
Valentin Ilief4f3efd2013-03-10 11:15:13 +0000552 pr_err("BUG: receive list not found for "
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800553 "dev %s, id %03X, mask %03X\n",
554 DNAME(dev), can_id, mask);
555 goto out;
556 }
557
558 rl = find_rcv_list(&can_id, &mask, d);
559
560 /*
561 * Search the receiver list for the item to delete. This should
562 * exist, since no receiver may be unregistered that hasn't
563 * been registered before.
564 */
565
Sasha Levinb67bfe02013-02-27 17:06:00 -0800566 hlist_for_each_entry_rcu(r, rl, list) {
Joe Perchesf64f9e72009-11-29 16:55:45 -0800567 if (r->can_id == can_id && r->mask == mask &&
568 r->func == func && r->data == data)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800569 break;
570 }
571
572 /*
Oliver Hartkoppc9bbb752013-03-18 07:52:06 +0000573 * Check for bugs in CAN protocol implementations using af_can.c:
574 * 'r' will be NULL if no matching list item was found for removal.
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800575 */
576
Sasha Levinb67bfe02013-02-27 17:06:00 -0800577 if (!r) {
Oliver Hartkoppc9bbb752013-03-18 07:52:06 +0000578 WARN(1, "BUG: receive list entry not found for dev %s, "
579 "id %03X, mask %03X\n", DNAME(dev), can_id, mask);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800580 goto out;
581 }
582
583 hlist_del_rcu(&r->list);
584 d->entries--;
585
586 if (can_pstats.rcv_entries > 0)
587 can_pstats.rcv_entries--;
588
589 /* remove device structure requested by NETDEV_UNREGISTER */
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000590 if (d->remove_on_zero_entries && !d->entries) {
591 kfree(d);
592 dev->ml_priv = NULL;
593 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800594
595 out:
596 spin_unlock(&can_rcvlists_lock);
597
598 /* schedule the receiver item for deletion */
599 if (r)
600 call_rcu(&r->rcu, can_rx_delete_receiver);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800601}
602EXPORT_SYMBOL(can_rx_unregister);
603
604static inline void deliver(struct sk_buff *skb, struct receiver *r)
605{
Oliver Hartkopp1fa17d42009-01-06 11:07:54 -0800606 r->func(skb, r->data);
607 r->matches++;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800608}
609
610static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
611{
612 struct receiver *r;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800613 int matches = 0;
614 struct can_frame *cf = (struct can_frame *)skb->data;
615 canid_t can_id = cf->can_id;
616
617 if (d->entries == 0)
618 return 0;
619
620 if (can_id & CAN_ERR_FLAG) {
Oliver Hartkoppd6e640f2012-05-08 22:20:33 +0200621 /* check for error message frame entries only */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800622 hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800623 if (can_id & r->mask) {
624 deliver(skb, r);
625 matches++;
626 }
627 }
628 return matches;
629 }
630
631 /* check for unfiltered entries */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800632 hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800633 deliver(skb, r);
634 matches++;
635 }
636
637 /* check for can_id/mask entries */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800638 hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800639 if ((can_id & r->mask) == r->can_id) {
640 deliver(skb, r);
641 matches++;
642 }
643 }
644
645 /* check for inverted can_id/mask entries */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800646 hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800647 if ((can_id & r->mask) != r->can_id) {
648 deliver(skb, r);
649 matches++;
650 }
651 }
652
Oliver Hartkoppf706644d2008-12-04 15:01:08 -0800653 /* check filterlists for single non-RTR can_ids */
654 if (can_id & CAN_RTR_FLAG)
655 return matches;
656
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800657 if (can_id & CAN_EFF_FLAG) {
Oliver Hartkopp45c70022014-04-02 20:25:26 +0200658 hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800659 if (r->can_id == can_id) {
660 deliver(skb, r);
661 matches++;
662 }
663 }
664 } else {
665 can_id &= CAN_SFF_MASK;
Sasha Levinb67bfe02013-02-27 17:06:00 -0800666 hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800667 deliver(skb, r);
668 matches++;
669 }
670 }
671
672 return matches;
673}
674
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200675static void can_receive(struct sk_buff *skb, struct net_device *dev)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800676{
677 struct dev_rcv_lists *d;
678 int matches;
679
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800680 /* update statistics */
681 can_stats.rx_frames++;
682 can_stats.rx_frames_delta++;
683
Oliver Hartkoppd3b58c42015-06-26 11:58:19 +0200684 /* create non-zero unique skb identifier together with *skb */
685 while (!(can_skb_prv(skb)->skbcnt))
686 can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter);
687
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800688 rcu_read_lock();
689
690 /* deliver the packet to sockets listening on all devices */
691 matches = can_rcv_filter(&can_rx_alldev_list, skb);
692
693 /* find receive list for this device */
694 d = find_dev_rcv_lists(dev);
695 if (d)
696 matches += can_rcv_filter(d, skb);
697
698 rcu_read_unlock();
699
Oliver Hartkopp62bcaa12009-04-17 01:38:46 -0700700 /* consume the skbuff allocated by the netdevice driver */
701 consume_skb(skb);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800702
703 if (matches > 0) {
704 can_stats.matches++;
705 can_stats.matches_delta++;
706 }
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200707}
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800708
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200709static int can_rcv(struct sk_buff *skb, struct net_device *dev,
710 struct packet_type *pt, struct net_device *orig_dev)
711{
712 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
713
714 if (unlikely(!net_eq(dev_net(dev), &init_net)))
715 goto drop;
716
717 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
718 skb->len != CAN_MTU ||
719 cfd->len > CAN_MAX_DLEN,
720 "PF_CAN: dropped non conform CAN skbuf: "
721 "dev type %d, len %d, datalen %d\n",
722 dev->type, skb->len, cfd->len))
723 goto drop;
724
725 can_receive(skb, dev);
726 return NET_RX_SUCCESS;
727
728drop:
729 kfree_skb(skb);
730 return NET_RX_DROP;
731}
732
733static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
734 struct packet_type *pt, struct net_device *orig_dev)
735{
736 struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
737
738 if (unlikely(!net_eq(dev_net(dev), &init_net)))
739 goto drop;
740
741 if (WARN_ONCE(dev->type != ARPHRD_CAN ||
742 skb->len != CANFD_MTU ||
743 cfd->len > CANFD_MAX_DLEN,
744 "PF_CAN: dropped non conform CAN FD skbuf: "
745 "dev type %d, len %d, datalen %d\n",
746 dev->type, skb->len, cfd->len))
747 goto drop;
748
749 can_receive(skb, dev);
Oliver Hartkopp6ca8b992009-08-29 06:45:09 +0000750 return NET_RX_SUCCESS;
Oliver Hartkopp1758c092009-08-13 22:54:25 +0000751
752drop:
753 kfree_skb(skb);
Oliver Hartkopp6ca8b992009-08-29 06:45:09 +0000754 return NET_RX_DROP;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800755}
756
757/*
758 * af_can protocol functions
759 */
760
761/**
762 * can_proto_register - register CAN transport protocol
763 * @cp: pointer to CAN protocol structure
764 *
765 * Return:
766 * 0 on success
767 * -EINVAL invalid (out of range) protocol number
768 * -EBUSY protocol already in use
769 * -ENOBUF if proto_register() fails
770 */
Kurt Van Dijck16506292011-05-03 18:40:57 +0000771int can_proto_register(const struct can_proto *cp)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800772{
773 int proto = cp->protocol;
774 int err = 0;
775
776 if (proto < 0 || proto >= CAN_NPROTO) {
Valentin Ilief4f3efd2013-03-10 11:15:13 +0000777 pr_err("can: protocol number %d out of range\n", proto);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800778 return -EINVAL;
779 }
780
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800781 err = proto_register(cp->prot, 0);
782 if (err < 0)
783 return err;
784
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000785 mutex_lock(&proto_tab_lock);
786
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800787 if (proto_tab[proto]) {
Valentin Ilief4f3efd2013-03-10 11:15:13 +0000788 pr_err("can: protocol %d already registered\n", proto);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800789 err = -EBUSY;
Oliver Hartkopp53914b62011-03-22 08:27:25 +0000790 } else
Stephen Hemmingera9b3cd72011-08-01 16:19:00 +0000791 RCU_INIT_POINTER(proto_tab[proto], cp);
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800792
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000793 mutex_unlock(&proto_tab_lock);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800794
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800795 if (err < 0)
796 proto_unregister(cp->prot);
797
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800798 return err;
799}
800EXPORT_SYMBOL(can_proto_register);
801
802/**
803 * can_proto_unregister - unregister CAN transport protocol
804 * @cp: pointer to CAN protocol structure
805 */
Kurt Van Dijck16506292011-05-03 18:40:57 +0000806void can_proto_unregister(const struct can_proto *cp)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800807{
808 int proto = cp->protocol;
809
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000810 mutex_lock(&proto_tab_lock);
811 BUG_ON(proto_tab[proto] != cp);
Stephen Hemmingera9b3cd72011-08-01 16:19:00 +0000812 RCU_INIT_POINTER(proto_tab[proto], NULL);
Oliver Hartkopp1ca050d2011-04-05 08:01:16 +0000813 mutex_unlock(&proto_tab_lock);
814
815 synchronize_rcu();
Urs Thuermanna2fea5f2008-02-07 18:04:45 -0800816
817 proto_unregister(cp->prot);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800818}
819EXPORT_SYMBOL(can_proto_unregister);
820
821/*
822 * af_can notifier to create/remove CAN netdevice specific structs
823 */
824static int can_notifier(struct notifier_block *nb, unsigned long msg,
Jiri Pirko351638e2013-05-28 01:30:21 +0000825 void *ptr)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800826{
Jiri Pirko351638e2013-05-28 01:30:21 +0000827 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800828 struct dev_rcv_lists *d;
829
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700830 if (!net_eq(dev_net(dev), &init_net))
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800831 return NOTIFY_DONE;
832
833 if (dev->type != ARPHRD_CAN)
834 return NOTIFY_DONE;
835
836 switch (msg) {
837
838 case NETDEV_REGISTER:
839
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000840 /* create new dev_rcv_lists for this device */
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800841 d = kzalloc(sizeof(*d), GFP_KERNEL);
Valentin Ilief4f3efd2013-03-10 11:15:13 +0000842 if (!d)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800843 return NOTIFY_DONE;
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000844 BUG_ON(dev->ml_priv);
845 dev->ml_priv = d;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800846
847 break;
848
849 case NETDEV_UNREGISTER:
850 spin_lock(&can_rcvlists_lock);
851
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000852 d = dev->ml_priv;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800853 if (d) {
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000854 if (d->entries)
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800855 d->remove_on_zero_entries = 1;
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000856 else {
857 kfree(d);
858 dev->ml_priv = NULL;
859 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800860 } else
Valentin Ilief4f3efd2013-03-10 11:15:13 +0000861 pr_err("can: notifier: receive list not found for dev "
862 "%s\n", dev->name);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800863
864 spin_unlock(&can_rcvlists_lock);
865
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800866 break;
867 }
868
869 return NOTIFY_DONE;
870}
871
872/*
873 * af_can module init/exit functions
874 */
875
876static struct packet_type can_packet __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -0800877 .type = cpu_to_be16(ETH_P_CAN),
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800878 .func = can_rcv,
879};
880
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200881static struct packet_type canfd_packet __read_mostly = {
882 .type = cpu_to_be16(ETH_P_CANFD),
883 .func = canfd_rcv,
884};
885
Stephen Hemmingerec1b4cf2009-10-05 05:58:39 +0000886static const struct net_proto_family can_family_ops = {
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800887 .family = PF_CAN,
888 .create = can_create,
889 .owner = THIS_MODULE,
890};
891
892/* notifier block for netdevice event */
893static struct notifier_block can_netdev_notifier __read_mostly = {
894 .notifier_call = can_notifier,
895};
896
897static __init int can_init(void)
898{
Oliver Hartkopp7c941632012-06-13 20:04:33 +0200899 /* check for correct padding to be able to use the structs similarly */
900 BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
901 offsetof(struct canfd_frame, len) ||
902 offsetof(struct can_frame, data) !=
903 offsetof(struct canfd_frame, data));
904
Jeremiah Mahlerb111b782014-11-21 23:42:35 -0800905 pr_info("can: controller area network core (" CAN_VERSION_STRING ")\n");
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800906
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000907 memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
908
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800909 rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
910 0, 0, NULL);
911 if (!rcv_cache)
912 return -ENOMEM;
913
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800914 if (stats_timer) {
915 /* the statistics are updated every second (timer triggered) */
916 setup_timer(&can_stattimer, can_stat_update, 0);
917 mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
918 } else
919 can_stattimer.function = NULL;
920
921 can_init_proc();
922
923 /* protocol register */
924 sock_register(&can_family_ops);
925 register_netdevice_notifier(&can_netdev_notifier);
926 dev_add_pack(&can_packet);
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200927 dev_add_pack(&canfd_packet);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800928
929 return 0;
930}
931
932static __exit void can_exit(void)
933{
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000934 struct net_device *dev;
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800935
936 if (stats_timer)
rajan.aggarwal85@gmail.comd9e64f82011-08-30 23:57:38 +0000937 del_timer_sync(&can_stattimer);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800938
939 can_remove_proc();
940
941 /* protocol unregister */
Oliver Hartkopp8b019392012-06-13 20:33:02 +0200942 dev_remove_pack(&canfd_packet);
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800943 dev_remove_pack(&can_packet);
944 unregister_netdevice_notifier(&can_netdev_notifier);
945 sock_unregister(PF_CAN);
946
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000947 /* remove created dev_rcv_lists from still registered CAN devices */
948 rcu_read_lock();
949 for_each_netdev_rcu(&init_net, dev) {
Valentin Ilief4f3efd2013-03-10 11:15:13 +0000950 if (dev->type == ARPHRD_CAN && dev->ml_priv) {
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000951
952 struct dev_rcv_lists *d = dev->ml_priv;
953
954 BUG_ON(d->entries);
955 kfree(d);
956 dev->ml_priv = NULL;
957 }
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800958 }
Oliver Hartkopp20dd3852009-12-25 06:47:47 +0000959 rcu_read_unlock();
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800960
Jesper Dangaard Brouer382bfee2009-06-08 03:11:38 +0000961 rcu_barrier(); /* Wait for completion of call_rcu()'s */
962
Oliver Hartkopp0d665482007-11-16 15:52:17 -0800963 kmem_cache_destroy(rcv_cache);
964}
965
966module_init(can_init);
967module_exit(can_exit);