1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 /* gw.c - CAN frame Gateway/Router/Bridge with netlink interface
3 *
4 * Copyright (c) 2019 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42 #include <linux/module.h>
43 #include <linux/init.h>
44 #include <linux/types.h>
45 #include <linux/kernel.h>
46 #include <linux/list.h>
47 #include <linux/spinlock.h>
48 #include <linux/rcupdate.h>
49 #include <linux/rculist.h>
50 #include <linux/net.h>
51 #include <linux/netdevice.h>
52 #include <linux/if_arp.h>
53 #include <linux/skbuff.h>
54 #include <linux/can.h>
55 #include <linux/can/core.h>
56 #include <linux/can/skb.h>
57 #include <linux/can/gw.h>
58 #include <net/rtnetlink.h>
59 #include <net/net_namespace.h>
60 #include <net/sock.h>
61
62 #define CAN_GW_NAME "can-gw"
63
64 MODULE_DESCRIPTION("PF_CAN netlink gateway");
65 MODULE_LICENSE("Dual BSD/GPL");
66 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
67 MODULE_ALIAS(CAN_GW_NAME);
68
69 #define CGW_MIN_HOPS 1
70 #define CGW_MAX_HOPS 6
71 #define CGW_DEFAULT_HOPS 1
72
73 static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
74 module_param(max_hops, uint, 0444);
75 MODULE_PARM_DESC(max_hops,
76 "maximum " CAN_GW_NAME " routing hops for CAN frames "
77 "(valid values: " __stringify(CGW_MIN_HOPS) "-"
78 __stringify(CGW_MAX_HOPS) " hops, "
79 "default: " __stringify(CGW_DEFAULT_HOPS) ")");
80
81 static struct notifier_block notifier;
82 static struct kmem_cache *cgw_cache __read_mostly;
83
84 /* structure that contains the (on-the-fly) CAN frame modifications */
85 struct cf_mod {
86 struct {
87 struct canfd_frame and;
88 struct canfd_frame or;
89 struct canfd_frame xor;
90 struct canfd_frame set;
91 } modframe;
92 struct {
93 u8 and;
94 u8 or;
95 u8 xor;
96 u8 set;
97 } modtype;
98 void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf,
99 struct cf_mod *mod);
100
101 /* CAN frame checksum calculation after CAN frame modifications */
102 struct {
103 struct cgw_csum_xor xor;
104 struct cgw_csum_crc8 crc8;
105 } csum;
106 struct {
107 void (*xor)(struct canfd_frame *cf,
108 struct cgw_csum_xor *xor);
109 void (*crc8)(struct canfd_frame *cf,
110 struct cgw_csum_crc8 *crc8);
111 } csumfunc;
112 u32 uid;
113 };
114
115 /* So far we just support CAN -> CAN routing and frame modifications.
116 *
117 * The internal can_can_gw structure contains data and attributes for
118 * a CAN -> CAN gateway job.
119 */
120 struct can_can_gw {
121 struct can_filter filter;
122 int src_idx;
123 int dst_idx;
124 };
125
126 /* list entry for CAN gateways jobs */
127 struct cgw_job {
128 struct hlist_node list;
129 struct rcu_head rcu;
130 u32 handled_frames;
131 u32 dropped_frames;
132 u32 deleted_frames;
133 struct cf_mod mod;
134 union {
135 /* CAN frame data source */
136 struct net_device *dev;
137 } src;
138 union {
139 /* CAN frame data destination */
140 struct net_device *dev;
141 } dst;
142 union {
143 struct can_can_gw ccgw;
144 /* tbc */
145 };
146 u8 gwtype;
147 u8 limit_hops;
148 u16 flags;
149 };
150
151 /* modification functions that are invoked in the hot path in can_can_gw_rcv */
152
153 #define MODFUNC(func, op) static void func(struct canfd_frame *cf, \
154 struct cf_mod *mod) { op ; }
155
156 MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
157 MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len)
158 MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags)
159 MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
160 MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
161 MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len)
162 MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags)
163 MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
164 MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
165 MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len)
166 MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags)
167 MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
168 MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
169 MODFUNC(mod_set_len, cf->len = mod->modframe.set.len)
170 MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags)
171 MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
172
mod_and_fddata(struct canfd_frame * cf,struct cf_mod * mod)173 static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod)
174 {
175 int i;
176
177 for (i = 0; i < CANFD_MAX_DLEN; i += 8)
178 *(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i);
179 }
180
mod_or_fddata(struct canfd_frame * cf,struct cf_mod * mod)181 static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod)
182 {
183 int i;
184
185 for (i = 0; i < CANFD_MAX_DLEN; i += 8)
186 *(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i);
187 }
188
mod_xor_fddata(struct canfd_frame * cf,struct cf_mod * mod)189 static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod)
190 {
191 int i;
192
193 for (i = 0; i < CANFD_MAX_DLEN; i += 8)
194 *(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i);
195 }
196
mod_set_fddata(struct canfd_frame * cf,struct cf_mod * mod)197 static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod)
198 {
199 memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN);
200 }
201
canframecpy(struct canfd_frame * dst,struct can_frame * src)202 static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
203 {
204 /* Copy the struct members separately to ensure that no uninitialized
205 * data are copied in the 3 bytes hole of the struct. This is needed
206 * to make easy compares of the data in the struct cf_mod.
207 */
208
209 dst->can_id = src->can_id;
210 dst->len = src->can_dlc;
211 *(u64 *)dst->data = *(u64 *)src->data;
212 }
213
canfdframecpy(struct canfd_frame * dst,struct canfd_frame * src)214 static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src)
215 {
216 /* Copy the struct members separately to ensure that no uninitialized
217 * data are copied in the 2 bytes hole of the struct. This is needed
218 * to make easy compares of the data in the struct cf_mod.
219 */
220
221 dst->can_id = src->can_id;
222 dst->flags = src->flags;
223 dst->len = src->len;
224 memcpy(dst->data, src->data, CANFD_MAX_DLEN);
225 }
226
cgw_chk_csum_parms(s8 fr,s8 to,s8 re,struct rtcanmsg * r)227 static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r)
228 {
229 s8 dlen = CAN_MAX_DLEN;
230
231 if (r->flags & CGW_FLAGS_CAN_FD)
232 dlen = CANFD_MAX_DLEN;
233
234 /* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
235 * relative to received dlc -1 .. -8 :
236 * e.g. for received dlc = 8
237 * -1 => index = 7 (data[7])
238 * -3 => index = 5 (data[5])
239 * -8 => index = 0 (data[0])
240 */
241
242 if (fr >= -dlen && fr < dlen &&
243 to >= -dlen && to < dlen &&
244 re >= -dlen && re < dlen)
245 return 0;
246 else
247 return -EINVAL;
248 }
249
calc_idx(int idx,int rx_len)250 static inline int calc_idx(int idx, int rx_len)
251 {
252 if (idx < 0)
253 return rx_len + idx;
254 else
255 return idx;
256 }
257
cgw_csum_xor_rel(struct canfd_frame * cf,struct cgw_csum_xor * xor)258 static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor)
259 {
260 int from = calc_idx(xor->from_idx, cf->len);
261 int to = calc_idx(xor->to_idx, cf->len);
262 int res = calc_idx(xor->result_idx, cf->len);
263 u8 val = xor->init_xor_val;
264 int i;
265
266 if (from < 0 || to < 0 || res < 0)
267 return;
268
269 if (from <= to) {
270 for (i = from; i <= to; i++)
271 val ^= cf->data[i];
272 } else {
273 for (i = from; i >= to; i--)
274 val ^= cf->data[i];
275 }
276
277 cf->data[res] = val;
278 }
279
cgw_csum_xor_pos(struct canfd_frame * cf,struct cgw_csum_xor * xor)280 static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor)
281 {
282 u8 val = xor->init_xor_val;
283 int i;
284
285 for (i = xor->from_idx; i <= xor->to_idx; i++)
286 val ^= cf->data[i];
287
288 cf->data[xor->result_idx] = val;
289 }
290
cgw_csum_xor_neg(struct canfd_frame * cf,struct cgw_csum_xor * xor)291 static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor)
292 {
293 u8 val = xor->init_xor_val;
294 int i;
295
296 for (i = xor->from_idx; i >= xor->to_idx; i--)
297 val ^= cf->data[i];
298
299 cf->data[xor->result_idx] = val;
300 }
301
cgw_csum_crc8_rel(struct canfd_frame * cf,struct cgw_csum_crc8 * crc8)302 static void cgw_csum_crc8_rel(struct canfd_frame *cf,
303 struct cgw_csum_crc8 *crc8)
304 {
305 int from = calc_idx(crc8->from_idx, cf->len);
306 int to = calc_idx(crc8->to_idx, cf->len);
307 int res = calc_idx(crc8->result_idx, cf->len);
308 u8 crc = crc8->init_crc_val;
309 int i;
310
311 if (from < 0 || to < 0 || res < 0)
312 return;
313
314 if (from <= to) {
315 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
316 crc = crc8->crctab[crc ^ cf->data[i]];
317 } else {
318 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
319 crc = crc8->crctab[crc ^ cf->data[i]];
320 }
321
322 switch (crc8->profile) {
323 case CGW_CRC8PRF_1U8:
324 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
325 break;
326
327 case CGW_CRC8PRF_16U8:
328 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
329 break;
330
331 case CGW_CRC8PRF_SFFID_XOR:
332 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
333 (cf->can_id >> 8 & 0xFF)];
334 break;
335 }
336
337 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
338 }
339
cgw_csum_crc8_pos(struct canfd_frame * cf,struct cgw_csum_crc8 * crc8)340 static void cgw_csum_crc8_pos(struct canfd_frame *cf,
341 struct cgw_csum_crc8 *crc8)
342 {
343 u8 crc = crc8->init_crc_val;
344 int i;
345
346 for (i = crc8->from_idx; i <= crc8->to_idx; i++)
347 crc = crc8->crctab[crc ^ cf->data[i]];
348
349 switch (crc8->profile) {
350 case CGW_CRC8PRF_1U8:
351 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
352 break;
353
354 case CGW_CRC8PRF_16U8:
355 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
356 break;
357
358 case CGW_CRC8PRF_SFFID_XOR:
359 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
360 (cf->can_id >> 8 & 0xFF)];
361 break;
362 }
363
364 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
365 }
366
cgw_csum_crc8_neg(struct canfd_frame * cf,struct cgw_csum_crc8 * crc8)367 static void cgw_csum_crc8_neg(struct canfd_frame *cf,
368 struct cgw_csum_crc8 *crc8)
369 {
370 u8 crc = crc8->init_crc_val;
371 int i;
372
373 for (i = crc8->from_idx; i >= crc8->to_idx; i--)
374 crc = crc8->crctab[crc ^ cf->data[i]];
375
376 switch (crc8->profile) {
377 case CGW_CRC8PRF_1U8:
378 crc = crc8->crctab[crc ^ crc8->profile_data[0]];
379 break;
380
381 case CGW_CRC8PRF_16U8:
382 crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
383 break;
384
385 case CGW_CRC8PRF_SFFID_XOR:
386 crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
387 (cf->can_id >> 8 & 0xFF)];
388 break;
389 }
390
391 cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
392 }
393
394 /* the receive & process & send function */
can_can_gw_rcv(struct sk_buff * skb,void * data)395 static void can_can_gw_rcv(struct sk_buff *skb, void *data)
396 {
397 struct cgw_job *gwj = (struct cgw_job *)data;
398 struct canfd_frame *cf;
399 struct sk_buff *nskb;
400 int modidx = 0;
401
402 /* process strictly Classic CAN or CAN FD frames */
403 if (gwj->flags & CGW_FLAGS_CAN_FD) {
404 if (skb->len != CANFD_MTU)
405 return;
406 } else {
407 if (skb->len != CAN_MTU)
408 return;
409 }
410
411 /* Do not handle CAN frames routed more than 'max_hops' times.
412 * In general we should never catch this delimiter which is intended
413 * to cover a misconfiguration protection (e.g. circular CAN routes).
414 *
415 * The Controller Area Network controllers only accept CAN frames with
416 * correct CRCs - which are not visible in the controller registers.
417 * According to skbuff.h documentation the csum_start element for IP
418 * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY.
419 * Only CAN skbs can be processed here which already have this property.
420 */
421
422 #define cgw_hops(skb) ((skb)->csum_start)
423
424 BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
425
426 if (cgw_hops(skb) >= max_hops) {
427 /* indicate deleted frames due to misconfiguration */
428 gwj->deleted_frames++;
429 return;
430 }
431
432 if (!(gwj->dst.dev->flags & IFF_UP)) {
433 gwj->dropped_frames++;
434 return;
435 }
436
437 /* is sending the skb back to the incoming interface not allowed? */
438 if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
439 can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex)
440 return;
441
442 /* clone the given skb, which has not been done in can_rcv()
443 *
444 * When there is at least one modification function activated,
445 * we need to copy the skb as we want to modify skb->data.
446 */
447 if (gwj->mod.modfunc[0])
448 nskb = skb_copy(skb, GFP_ATOMIC);
449 else
450 nskb = skb_clone(skb, GFP_ATOMIC);
451
452 if (!nskb) {
453 gwj->dropped_frames++;
454 return;
455 }
456
457 /* put the incremented hop counter in the cloned skb */
458 cgw_hops(nskb) = cgw_hops(skb) + 1;
459
460 /* first processing of this CAN frame -> adjust to private hop limit */
461 if (gwj->limit_hops && cgw_hops(nskb) == 1)
462 cgw_hops(nskb) = max_hops - gwj->limit_hops + 1;
463
464 nskb->dev = gwj->dst.dev;
465
466 /* pointer to modifiable CAN frame */
467 cf = (struct canfd_frame *)nskb->data;
468
469 /* perform preprocessed modification functions if there are any */
470 while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx])
471 (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod);
472
473 /* Has the CAN frame been modified? */
474 if (modidx) {
475 /* get available space for the processed CAN frame type */
476 int max_len = nskb->len - offsetof(struct canfd_frame, data);
477
478 /* dlc may have changed, make sure it fits to the CAN frame */
479 if (cf->len > max_len) {
480 /* delete frame due to misconfiguration */
481 gwj->deleted_frames++;
482 kfree_skb(nskb);
483 return;
484 }
485
486 /* check for checksum updates */
487 if (gwj->mod.csumfunc.crc8)
488 (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8);
489
490 if (gwj->mod.csumfunc.xor)
491 (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor);
492 }
493
494 /* clear the skb timestamp if not configured the other way */
495 if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
496 nskb->tstamp = 0;
497
498 /* send to netdevice */
499 if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
500 gwj->dropped_frames++;
501 else
502 gwj->handled_frames++;
503 }
504
cgw_register_filter(struct net * net,struct cgw_job * gwj)505 static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
506 {
507 return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
508 gwj->ccgw.filter.can_mask, can_can_gw_rcv,
509 gwj, "gw", NULL);
510 }
511
cgw_unregister_filter(struct net * net,struct cgw_job * gwj)512 static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
513 {
514 can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
515 gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
516 }
517
cgw_notifier(struct notifier_block * nb,unsigned long msg,void * ptr)518 static int cgw_notifier(struct notifier_block *nb,
519 unsigned long msg, void *ptr)
520 {
521 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
522 struct net *net = dev_net(dev);
523
524 if (dev->type != ARPHRD_CAN)
525 return NOTIFY_DONE;
526
527 if (msg == NETDEV_UNREGISTER) {
528 struct cgw_job *gwj = NULL;
529 struct hlist_node *nx;
530
531 ASSERT_RTNL();
532
533 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
534 if (gwj->src.dev == dev || gwj->dst.dev == dev) {
535 hlist_del(&gwj->list);
536 cgw_unregister_filter(net, gwj);
537 synchronize_rcu();
538 kmem_cache_free(cgw_cache, gwj);
539 }
540 }
541 }
542
543 return NOTIFY_DONE;
544 }
545
cgw_put_job(struct sk_buff * skb,struct cgw_job * gwj,int type,u32 pid,u32 seq,int flags)546 static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
547 u32 pid, u32 seq, int flags)
548 {
549 struct rtcanmsg *rtcan;
550 struct nlmsghdr *nlh;
551
552 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags);
553 if (!nlh)
554 return -EMSGSIZE;
555
556 rtcan = nlmsg_data(nlh);
557 rtcan->can_family = AF_CAN;
558 rtcan->gwtype = gwj->gwtype;
559 rtcan->flags = gwj->flags;
560
561 /* add statistics if available */
562
563 if (gwj->handled_frames) {
564 if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
565 goto cancel;
566 }
567
568 if (gwj->dropped_frames) {
569 if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
570 goto cancel;
571 }
572
573 if (gwj->deleted_frames) {
574 if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
575 goto cancel;
576 }
577
578 /* check non default settings of attributes */
579
580 if (gwj->limit_hops) {
581 if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0)
582 goto cancel;
583 }
584
585 if (gwj->flags & CGW_FLAGS_CAN_FD) {
586 struct cgw_fdframe_mod mb;
587
588 if (gwj->mod.modtype.and) {
589 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
590 mb.modtype = gwj->mod.modtype.and;
591 if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0)
592 goto cancel;
593 }
594
595 if (gwj->mod.modtype.or) {
596 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
597 mb.modtype = gwj->mod.modtype.or;
598 if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0)
599 goto cancel;
600 }
601
602 if (gwj->mod.modtype.xor) {
603 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
604 mb.modtype = gwj->mod.modtype.xor;
605 if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0)
606 goto cancel;
607 }
608
609 if (gwj->mod.modtype.set) {
610 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
611 mb.modtype = gwj->mod.modtype.set;
612 if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0)
613 goto cancel;
614 }
615 } else {
616 struct cgw_frame_mod mb;
617
618 if (gwj->mod.modtype.and) {
619 memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf));
620 mb.modtype = gwj->mod.modtype.and;
621 if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
622 goto cancel;
623 }
624
625 if (gwj->mod.modtype.or) {
626 memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf));
627 mb.modtype = gwj->mod.modtype.or;
628 if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
629 goto cancel;
630 }
631
632 if (gwj->mod.modtype.xor) {
633 memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf));
634 mb.modtype = gwj->mod.modtype.xor;
635 if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
636 goto cancel;
637 }
638
639 if (gwj->mod.modtype.set) {
640 memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf));
641 mb.modtype = gwj->mod.modtype.set;
642 if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
643 goto cancel;
644 }
645 }
646
647 if (gwj->mod.uid) {
648 if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0)
649 goto cancel;
650 }
651
652 if (gwj->mod.csumfunc.crc8) {
653 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
654 &gwj->mod.csum.crc8) < 0)
655 goto cancel;
656 }
657
658 if (gwj->mod.csumfunc.xor) {
659 if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
660 &gwj->mod.csum.xor) < 0)
661 goto cancel;
662 }
663
664 if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
665 if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
666 if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
667 &gwj->ccgw.filter) < 0)
668 goto cancel;
669 }
670
671 if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
672 goto cancel;
673
674 if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
675 goto cancel;
676 }
677
678 nlmsg_end(skb, nlh);
679 return 0;
680
681 cancel:
682 nlmsg_cancel(skb, nlh);
683 return -EMSGSIZE;
684 }
685
686 /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
cgw_dump_jobs(struct sk_buff * skb,struct netlink_callback * cb)687 static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
688 {
689 struct net *net = sock_net(skb->sk);
690 struct cgw_job *gwj = NULL;
691 int idx = 0;
692 int s_idx = cb->args[0];
693
694 rcu_read_lock();
695 hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
696 if (idx < s_idx)
697 goto cont;
698
699 if (cgw_put_job(skb, gwj, RTM_NEWROUTE,
700 NETLINK_CB(cb->skb).portid,
701 cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0)
702 break;
703 cont:
704 idx++;
705 }
706 rcu_read_unlock();
707
708 cb->args[0] = idx;
709
710 return skb->len;
711 }
712
713 static const struct nla_policy cgw_policy[CGW_MAX + 1] = {
714 [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) },
715 [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) },
716 [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) },
717 [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) },
718 [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) },
719 [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) },
720 [CGW_SRC_IF] = { .type = NLA_U32 },
721 [CGW_DST_IF] = { .type = NLA_U32 },
722 [CGW_FILTER] = { .len = sizeof(struct can_filter) },
723 [CGW_LIM_HOPS] = { .type = NLA_U8 },
724 [CGW_MOD_UID] = { .type = NLA_U32 },
725 [CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) },
726 [CGW_FDMOD_OR] = { .len = sizeof(struct cgw_fdframe_mod) },
727 [CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) },
728 [CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) },
729 };
730
731 /* check for common and gwtype specific attributes */
cgw_parse_attr(struct nlmsghdr * nlh,struct cf_mod * mod,u8 gwtype,void * gwtypeattr,u8 * limhops)732 static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
733 u8 gwtype, void *gwtypeattr, u8 *limhops)
734 {
735 struct nlattr *tb[CGW_MAX + 1];
736 struct rtcanmsg *r = nlmsg_data(nlh);
737 int modidx = 0;
738 int err = 0;
739
740 /* initialize modification & checksum data space */
741 memset(mod, 0, sizeof(*mod));
742
743 err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb,
744 CGW_MAX, cgw_policy, NULL);
745 if (err < 0)
746 return err;
747
748 if (tb[CGW_LIM_HOPS]) {
749 *limhops = nla_get_u8(tb[CGW_LIM_HOPS]);
750
751 if (*limhops < 1 || *limhops > max_hops)
752 return -EINVAL;
753 }
754
755 /* check for AND/OR/XOR/SET modifications */
756 if (r->flags & CGW_FLAGS_CAN_FD) {
757 struct cgw_fdframe_mod mb;
758
759 if (tb[CGW_FDMOD_AND]) {
760 nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN);
761
762 canfdframecpy(&mod->modframe.and, &mb.cf);
763 mod->modtype.and = mb.modtype;
764
765 if (mb.modtype & CGW_MOD_ID)
766 mod->modfunc[modidx++] = mod_and_id;
767
768 if (mb.modtype & CGW_MOD_LEN)
769 mod->modfunc[modidx++] = mod_and_len;
770
771 if (mb.modtype & CGW_MOD_FLAGS)
772 mod->modfunc[modidx++] = mod_and_flags;
773
774 if (mb.modtype & CGW_MOD_DATA)
775 mod->modfunc[modidx++] = mod_and_fddata;
776 }
777
778 if (tb[CGW_FDMOD_OR]) {
779 nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN);
780
781 canfdframecpy(&mod->modframe.or, &mb.cf);
782 mod->modtype.or = mb.modtype;
783
784 if (mb.modtype & CGW_MOD_ID)
785 mod->modfunc[modidx++] = mod_or_id;
786
787 if (mb.modtype & CGW_MOD_LEN)
788 mod->modfunc[modidx++] = mod_or_len;
789
790 if (mb.modtype & CGW_MOD_FLAGS)
791 mod->modfunc[modidx++] = mod_or_flags;
792
793 if (mb.modtype & CGW_MOD_DATA)
794 mod->modfunc[modidx++] = mod_or_fddata;
795 }
796
797 if (tb[CGW_FDMOD_XOR]) {
798 nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN);
799
800 canfdframecpy(&mod->modframe.xor, &mb.cf);
801 mod->modtype.xor = mb.modtype;
802
803 if (mb.modtype & CGW_MOD_ID)
804 mod->modfunc[modidx++] = mod_xor_id;
805
806 if (mb.modtype & CGW_MOD_LEN)
807 mod->modfunc[modidx++] = mod_xor_len;
808
809 if (mb.modtype & CGW_MOD_FLAGS)
810 mod->modfunc[modidx++] = mod_xor_flags;
811
812 if (mb.modtype & CGW_MOD_DATA)
813 mod->modfunc[modidx++] = mod_xor_fddata;
814 }
815
816 if (tb[CGW_FDMOD_SET]) {
817 nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN);
818
819 canfdframecpy(&mod->modframe.set, &mb.cf);
820 mod->modtype.set = mb.modtype;
821
822 if (mb.modtype & CGW_MOD_ID)
823 mod->modfunc[modidx++] = mod_set_id;
824
825 if (mb.modtype & CGW_MOD_LEN)
826 mod->modfunc[modidx++] = mod_set_len;
827
828 if (mb.modtype & CGW_MOD_FLAGS)
829 mod->modfunc[modidx++] = mod_set_flags;
830
831 if (mb.modtype & CGW_MOD_DATA)
832 mod->modfunc[modidx++] = mod_set_fddata;
833 }
834 } else {
835 struct cgw_frame_mod mb;
836
837 if (tb[CGW_MOD_AND]) {
838 nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
839
840 canframecpy(&mod->modframe.and, &mb.cf);
841 mod->modtype.and = mb.modtype;
842
843 if (mb.modtype & CGW_MOD_ID)
844 mod->modfunc[modidx++] = mod_and_id;
845
846 if (mb.modtype & CGW_MOD_LEN)
847 mod->modfunc[modidx++] = mod_and_len;
848
849 if (mb.modtype & CGW_MOD_DATA)
850 mod->modfunc[modidx++] = mod_and_data;
851 }
852
853 if (tb[CGW_MOD_OR]) {
854 nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
855
856 canframecpy(&mod->modframe.or, &mb.cf);
857 mod->modtype.or = mb.modtype;
858
859 if (mb.modtype & CGW_MOD_ID)
860 mod->modfunc[modidx++] = mod_or_id;
861
862 if (mb.modtype & CGW_MOD_LEN)
863 mod->modfunc[modidx++] = mod_or_len;
864
865 if (mb.modtype & CGW_MOD_DATA)
866 mod->modfunc[modidx++] = mod_or_data;
867 }
868
869 if (tb[CGW_MOD_XOR]) {
870 nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
871
872 canframecpy(&mod->modframe.xor, &mb.cf);
873 mod->modtype.xor = mb.modtype;
874
875 if (mb.modtype & CGW_MOD_ID)
876 mod->modfunc[modidx++] = mod_xor_id;
877
878 if (mb.modtype & CGW_MOD_LEN)
879 mod->modfunc[modidx++] = mod_xor_len;
880
881 if (mb.modtype & CGW_MOD_DATA)
882 mod->modfunc[modidx++] = mod_xor_data;
883 }
884
885 if (tb[CGW_MOD_SET]) {
886 nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
887
888 canframecpy(&mod->modframe.set, &mb.cf);
889 mod->modtype.set = mb.modtype;
890
891 if (mb.modtype & CGW_MOD_ID)
892 mod->modfunc[modidx++] = mod_set_id;
893
894 if (mb.modtype & CGW_MOD_LEN)
895 mod->modfunc[modidx++] = mod_set_len;
896
897 if (mb.modtype & CGW_MOD_DATA)
898 mod->modfunc[modidx++] = mod_set_data;
899 }
900 }
901
902 /* check for checksum operations after CAN frame modifications */
903 if (modidx) {
904 if (tb[CGW_CS_CRC8]) {
905 struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]);
906
907 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
908 c->result_idx, r);
909 if (err)
910 return err;
911
912 nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
913 CGW_CS_CRC8_LEN);
914
915 /* select dedicated processing function to reduce
916 * runtime operations in receive hot path.
917 */
918 if (c->from_idx < 0 || c->to_idx < 0 ||
919 c->result_idx < 0)
920 mod->csumfunc.crc8 = cgw_csum_crc8_rel;
921 else if (c->from_idx <= c->to_idx)
922 mod->csumfunc.crc8 = cgw_csum_crc8_pos;
923 else
924 mod->csumfunc.crc8 = cgw_csum_crc8_neg;
925 }
926
927 if (tb[CGW_CS_XOR]) {
928 struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]);
929
930 err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
931 c->result_idx, r);
932 if (err)
933 return err;
934
935 nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR],
936 CGW_CS_XOR_LEN);
937
938 /* select dedicated processing function to reduce
939 * runtime operations in receive hot path.
940 */
941 if (c->from_idx < 0 || c->to_idx < 0 ||
942 c->result_idx < 0)
943 mod->csumfunc.xor = cgw_csum_xor_rel;
944 else if (c->from_idx <= c->to_idx)
945 mod->csumfunc.xor = cgw_csum_xor_pos;
946 else
947 mod->csumfunc.xor = cgw_csum_xor_neg;
948 }
949
950 if (tb[CGW_MOD_UID])
951 nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32));
952 }
953
954 if (gwtype == CGW_TYPE_CAN_CAN) {
955 /* check CGW_TYPE_CAN_CAN specific attributes */
956 struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr;
957
958 memset(ccgw, 0, sizeof(*ccgw));
959
960 /* check for can_filter in attributes */
961 if (tb[CGW_FILTER])
962 nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
963 sizeof(struct can_filter));
964
965 err = -ENODEV;
966
967 /* specifying two interfaces is mandatory */
968 if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
969 return err;
970
971 ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]);
972 ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]);
973
974 /* both indices set to 0 for flushing all routing entries */
975 if (!ccgw->src_idx && !ccgw->dst_idx)
976 return 0;
977
978 /* only one index set to 0 is an error */
979 if (!ccgw->src_idx || !ccgw->dst_idx)
980 return err;
981 }
982
983 /* add the checks for other gwtypes here */
984
985 return 0;
986 }
987
cgw_create_job(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)988 static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh,
989 struct netlink_ext_ack *extack)
990 {
991 struct net *net = sock_net(skb->sk);
992 struct rtcanmsg *r;
993 struct cgw_job *gwj;
994 struct cf_mod mod;
995 struct can_can_gw ccgw;
996 u8 limhops = 0;
997 int err = 0;
998
999 if (!netlink_capable(skb, CAP_NET_ADMIN))
1000 return -EPERM;
1001
1002 if (nlmsg_len(nlh) < sizeof(*r))
1003 return -EINVAL;
1004
1005 r = nlmsg_data(nlh);
1006 if (r->can_family != AF_CAN)
1007 return -EPFNOSUPPORT;
1008
1009 /* so far we only support CAN -> CAN routings */
1010 if (r->gwtype != CGW_TYPE_CAN_CAN)
1011 return -EINVAL;
1012
1013 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
1014 if (err < 0)
1015 return err;
1016
1017 if (mod.uid) {
1018 ASSERT_RTNL();
1019
1020 /* check for updating an existing job with identical uid */
1021 hlist_for_each_entry(gwj, &net->can.cgw_list, list) {
1022 if (gwj->mod.uid != mod.uid)
1023 continue;
1024
1025 /* interfaces & filters must be identical */
1026 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
1027 return -EINVAL;
1028
1029 /* update modifications with disabled softirq & quit */
1030 local_bh_disable();
1031 memcpy(&gwj->mod, &mod, sizeof(mod));
1032 local_bh_enable();
1033 return 0;
1034 }
1035 }
1036
1037 /* ifindex == 0 is not allowed for job creation */
1038 if (!ccgw.src_idx || !ccgw.dst_idx)
1039 return -ENODEV;
1040
1041 gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
1042 if (!gwj)
1043 return -ENOMEM;
1044
1045 gwj->handled_frames = 0;
1046 gwj->dropped_frames = 0;
1047 gwj->deleted_frames = 0;
1048 gwj->flags = r->flags;
1049 gwj->gwtype = r->gwtype;
1050 gwj->limit_hops = limhops;
1051
1052 /* insert already parsed information */
1053 memcpy(&gwj->mod, &mod, sizeof(mod));
1054 memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw));
1055
1056 err = -ENODEV;
1057
1058 gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx);
1059
1060 if (!gwj->src.dev)
1061 goto out;
1062
1063 if (gwj->src.dev->type != ARPHRD_CAN)
1064 goto out;
1065
1066 gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
1067
1068 if (!gwj->dst.dev)
1069 goto out;
1070
1071 if (gwj->dst.dev->type != ARPHRD_CAN)
1072 goto out;
1073
1074 ASSERT_RTNL();
1075
1076 err = cgw_register_filter(net, gwj);
1077 if (!err)
1078 hlist_add_head_rcu(&gwj->list, &net->can.cgw_list);
1079 out:
1080 if (err)
1081 kmem_cache_free(cgw_cache, gwj);
1082
1083 return err;
1084 }
1085
cgw_remove_all_jobs(struct net * net)1086 static void cgw_remove_all_jobs(struct net *net)
1087 {
1088 struct cgw_job *gwj = NULL;
1089 struct hlist_node *nx;
1090
1091 ASSERT_RTNL();
1092
1093 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
1094 hlist_del(&gwj->list);
1095 cgw_unregister_filter(net, gwj);
1096 synchronize_rcu();
1097 kmem_cache_free(cgw_cache, gwj);
1098 }
1099 }
1100
cgw_remove_job(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1101 static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
1102 struct netlink_ext_ack *extack)
1103 {
1104 struct net *net = sock_net(skb->sk);
1105 struct cgw_job *gwj = NULL;
1106 struct hlist_node *nx;
1107 struct rtcanmsg *r;
1108 struct cf_mod mod;
1109 struct can_can_gw ccgw;
1110 u8 limhops = 0;
1111 int err = 0;
1112
1113 if (!netlink_capable(skb, CAP_NET_ADMIN))
1114 return -EPERM;
1115
1116 if (nlmsg_len(nlh) < sizeof(*r))
1117 return -EINVAL;
1118
1119 r = nlmsg_data(nlh);
1120 if (r->can_family != AF_CAN)
1121 return -EPFNOSUPPORT;
1122
1123 /* so far we only support CAN -> CAN routings */
1124 if (r->gwtype != CGW_TYPE_CAN_CAN)
1125 return -EINVAL;
1126
1127 err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
1128 if (err < 0)
1129 return err;
1130
1131 /* two interface indices both set to 0 => remove all entries */
1132 if (!ccgw.src_idx && !ccgw.dst_idx) {
1133 cgw_remove_all_jobs(net);
1134 return 0;
1135 }
1136
1137 err = -EINVAL;
1138
1139 ASSERT_RTNL();
1140
1141 /* remove only the first matching entry */
1142 hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
1143 if (gwj->flags != r->flags)
1144 continue;
1145
1146 if (gwj->limit_hops != limhops)
1147 continue;
1148
1149 /* we have a match when uid is enabled and identical */
1150 if (gwj->mod.uid || mod.uid) {
1151 if (gwj->mod.uid != mod.uid)
1152 continue;
1153 } else {
1154 /* no uid => check for identical modifications */
1155 if (memcmp(&gwj->mod, &mod, sizeof(mod)))
1156 continue;
1157 }
1158
1159 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
1160 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
1161 continue;
1162
1163 hlist_del(&gwj->list);
1164 cgw_unregister_filter(net, gwj);
1165 synchronize_rcu();
1166 kmem_cache_free(cgw_cache, gwj);
1167 err = 0;
1168 break;
1169 }
1170
1171 return err;
1172 }
1173
cangw_pernet_init(struct net * net)1174 static int __net_init cangw_pernet_init(struct net *net)
1175 {
1176 INIT_HLIST_HEAD(&net->can.cgw_list);
1177 return 0;
1178 }
1179
cangw_pernet_exit(struct net * net)1180 static void __net_exit cangw_pernet_exit(struct net *net)
1181 {
1182 rtnl_lock();
1183 cgw_remove_all_jobs(net);
1184 rtnl_unlock();
1185 }
1186
1187 static struct pernet_operations cangw_pernet_ops = {
1188 .init = cangw_pernet_init,
1189 .exit = cangw_pernet_exit,
1190 };
1191
cgw_module_init(void)1192 static __init int cgw_module_init(void)
1193 {
1194 int ret;
1195
1196 /* sanitize given module parameter */
1197 max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS);
1198
1199 pr_info("can: netlink gateway - max_hops=%d\n", max_hops);
1200
1201 ret = register_pernet_subsys(&cangw_pernet_ops);
1202 if (ret)
1203 return ret;
1204
1205 ret = -ENOMEM;
1206 cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
1207 0, 0, NULL);
1208 if (!cgw_cache)
1209 goto out_cache_create;
1210
1211 /* set notifier */
1212 notifier.notifier_call = cgw_notifier;
1213 ret = register_netdevice_notifier(¬ifier);
1214 if (ret)
1215 goto out_register_notifier;
1216
1217 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE,
1218 NULL, cgw_dump_jobs, 0);
1219 if (ret)
1220 goto out_rtnl_register1;
1221
1222 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE,
1223 cgw_create_job, NULL, 0);
1224 if (ret)
1225 goto out_rtnl_register2;
1226 ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE,
1227 cgw_remove_job, NULL, 0);
1228 if (ret)
1229 goto out_rtnl_register3;
1230
1231 return 0;
1232
1233 out_rtnl_register3:
1234 rtnl_unregister(PF_CAN, RTM_NEWROUTE);
1235 out_rtnl_register2:
1236 rtnl_unregister(PF_CAN, RTM_GETROUTE);
1237 out_rtnl_register1:
1238 unregister_netdevice_notifier(¬ifier);
1239 out_register_notifier:
1240 kmem_cache_destroy(cgw_cache);
1241 out_cache_create:
1242 unregister_pernet_subsys(&cangw_pernet_ops);
1243
1244 return ret;
1245 }
1246
cgw_module_exit(void)1247 static __exit void cgw_module_exit(void)
1248 {
1249 rtnl_unregister_all(PF_CAN);
1250
1251 unregister_netdevice_notifier(¬ifier);
1252
1253 unregister_pernet_subsys(&cangw_pernet_ops);
1254 rcu_barrier(); /* Wait for completion of call_rcu()'s */
1255
1256 kmem_cache_destroy(cgw_cache);
1257 }
1258
1259 module_init(cgw_module_init);
1260 module_exit(cgw_module_exit);
1261